An Introduction to the History of Science
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Transcriber's note:
Every effort has been made to replicate this text as
faithfully as possible. Some changes have been made.
They are listed at the end of the text, apart from
some changes of puctuation in the Index.
Text enclosed by underscores is in italics (_italics_).
Characters enclosed by curly braces are subscripts
(example: H{2}O).
Dalton's symbols for the elements have been represented
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Circle with vertical bar (|) Nitrogen
Circle with central dot (·) Oxygen
Black cirle (*) Carbon
AN INTRODUCTION TO THE HISTORY OF SCIENCE
by
WALTER LIBBY, M.A., Ph.D.
Professor of the History of Science
in the Carnegie Institute of Technology
[Illustration]
Boston New York Chicago
Houghton Mifflin Company
The Riverside Press Cambridge
Copyright, 1917, by Walter Libby
All Rights Reserved
The Riverside Press
Cambridge. Massachusetts
U . S . A
TO MY STUDENTS OF THE LAST TWELVE YEARS IN THE CHICAGO AND
PITTSBURGH DISTRICTS THIS BOOK IS INSCRIBED IN FURTHERANCE OF THE
ENDEAVOR TO INCULCATE A DEMOCRATIC CULTURE, EVER MINDFUL OF THE
DAILY TASK, NOT ALTOGETHER IGNORANT OF THE ACHIEVEMENTS OF THE PAST
PREFACE
The history of science has something to offer to the humblest
intelligence. It is a means of imparting a knowledge of scientific facts
and principles to unschooled minds. At the same time it affords a simple
method of school instruction. Those who understand a business or an
institution best, as a contemporary writer on finance remarks, are those
who have made it or grown up with it, and the next best thing is to know
how it has grown up, and then watch or take part in its actual working.
Generally speaking, we know best what we know in its origins.
The history of science is an aid in scientific research. It places the
student in the current of scientific thought, and gives him a clue to
the purpose and necessity of the theories he is required to master. It
presents science as the constant pursuit of truth rather than the
formulation of truth long since revealed; it shows science as
progressive rather than fixed, dynamic rather than static, a growth to
which each may contribute. It does not paralyze the self-activity of
youth by the record of an infallible past.
It is only by teaching the sciences in their historical development that
the schools can be true to the two principles of modern education, that
the sciences should occupy the foremost place in the curriculum and that
the individual mind in its evolution should rehearse the history of
civilization.
The history of science should be given a larger place than at present in
general history; for, as Bacon said, the history of the world without a
history of learning is like a statue of Polyphemus with the eye out. The
history of science studies the past for the sake of the future. It is a
story of continuous progress. It is rich in biographical material. It
shows the sciences in their interrelations, and saves the student from
narrowness and premature specialization. It affords a unique approach to
the study of philosophy. It gives new motive to the study of foreign
languages. It gives an interest in the applications of knowledge, offers
a clue to the complex civilization of the present, and renders the mind
hospitable to new discoveries and inventions.
The history of science is hostile to the spirit of caste. It shows the
sciences rising from daily needs and occupations, formulated by
philosophy, enriching philosophy, giving rise to new industries, which
react in turn upon the sciences. The history of science reveals men of
all grades of intelligence and of all social ranks coöperating in the
cause of human progress. It is a basis of intellectual and social
homogeneity.
Science is international, English, Germans, French, Italians,
Russians--all nations--contributing to advance the general interests.
Accordingly, a survey of the sciences tends to increase mutual respect,
and to heighten the humanitarian sentiment. The history of science can
be taught to people of all creeds and colors, and cannot fail to enhance
in the breast of every young man, or woman, faith in human progress and
good-will to all mankind.
This book is intended as a simple introduction, taking advantage of the
interests of youth of from seventeen to twenty-two years of age (and
their intellectual compeers) in order to direct their attention to the
story of the development of the sciences. It makes no claim to be in any
sense complete or comprehensive. It is, therefore, a psychological
introduction, having the mental capacity of a certain class of readers
always in view, rather than a logical introduction, which would
presuppose in all readers both full maturity of intellect and
considerable initial interest in the history of science.
I cannot conclude this preface without thanking those who have assisted
me in the preparation of this book--Sir William Osler, who read the
first draft of the manuscript, and aided me with his counsel; Dr.
Charles Singer, who read all the chapters in manuscript, and to whom I
am indebted for advice in reference to the illustrations and for many
other valuable suggestions; the officers of the Bodleian Library, whose
courtesy was unfailing during the year I worked there; Professor Henry
Crew, who helped in the revision of two of the chapters by his judicious
criticism; Professor J. E. Rush, whose knowledge of bacteriology
improved the chapter on Pasteur; Professor L. O. Grondahl, who read one
of the chapters relating to the history of physics and suggested
important emendations; and Dr. John A. Brashear, who contributed
valuable information in reference to the activities of Samuel Pierpont
Langley. I wish to express my gratitude also to Miss Florence Bonnet for
aid in the correction of the manuscript.
W. LIBBY.
February 2, 1917.
CONTENTS
I. SCIENCE AND PRACTICAL NEEDS--EGYPT AND BABYLONIA 1
II. THE INFLUENCE OF ABSTRACT THOUGHT--GREECE: ARISTOTLE 15
III. SCIENTIFIC THEORY SUBORDINATED TO APPLICATION--ROME:
VITRUVIUS 30
IV. THE CONTINUITY OF SCIENCE--THE MEDIEVAL CHURCH AND
THE ARABS 43
V. THE CLASSIFICATION OF THE SCIENCES--FRANCIS BACON 57
VI. SCIENTIFIC METHOD--GILBERT, GALILEO, HARVEY, DESCARTES 72
VII. SCIENCE AS MEASUREMENT--TYCHO BRAHE, KEPLER, BOYLE 86
VIII. COÖPERATION IN SCIENCE--THE ROYAL SOCIETY 99
IX. SCIENCE AND THE STRUGGLE FOR LIBERTY--BENJAMIN FRANKLIN 114
X. THE INTERACTION OF THE SCIENCES--WERNER, HUTTON, BLACK,
HALL, WILLIAM SMITH 129
XI. SCIENCE AND RELIGION--KANT, LAMBERT, LAPLACE, SIR
WILLIAM HERSCHEL 142
XII. THE REIGN OF LAW--DALTON, JOULE 155
XIII. THE SCIENTIST--SIR HUMPHRY DAVY 170
XIV. SCIENTIFIC PREDICTION--THE DISCOVERY OF NEPTUNE 184
XV. SCIENCE AND TRAVEL--THE VOYAGE OF THE BEAGLE 197
XVI. SCIENCE AND WAR--PASTEUR, LISTER 213
XVII. SCIENCE AND INVENTION--LANGLEY'S AEROPLANE 231
XVIII. SCIENTIFIC HYPOTHESIS--RADIOACTIVE SUBSTANCES 245
XIX. THE SCIENTIFIC IMAGINATION 258
XX. SCIENCE AND DEMOCRATIC CULTURE 270
INDEX 283
ILLUSTRATIONS
EARLIEST PICTURE KNOWN OF A SURGICAL OPERATION.
EGYPT, 2500 B.C. 6
ST. THOMAS AQUINAS OVERCOMING AVERROËS 54
DR. GILBERT SHOWING HIS ELECTRICAL EXPERIMENTS
TO QUEEN ELIZABETH AND HER COURT 72
THE TICHONIC QUADRANT 88
WADHAM COLLEGE, OXFORD 104
SIR ISAAC NEWTON 112
JOHN DALTON COLLECTING MARSH GAS 162
THE FIRST SUCCESSFUL HEAVIER-THAN-AIR FLYING MACHINE 236
AN INTRODUCTION TO THE HISTORY OF SCIENCE
CHAPTER I
SCIENCE AND PRACTICAL NEEDS--EGYPT AND BABYLONIA
If you consult encyclopedias and special works in reference to the early
history of any one of the sciences,--astronomy, geology, geometry,
physiology, logic, or political science, for example,--you will find
strongly emphasized the part played by the Greeks in the development of
organized knowledge. Great, indeed, as we shall see in the next chapter,
are the contributions to the growth of science of this highly rational
and speculative people. It must be conceded, also, that the influence on
Western science of civilizations earlier than theirs has come to us, to
a considerable extent at least, through the channels of Greek
literature.
Nevertheless, if you seek the very origins of the sciences, you will
inevitably be drawn to the banks of the Nile, and to the valleys of the
Tigris and the Euphrates. Here, in Egypt, in Assyria and Babylonia,
dwelt from very remote times nations whose genius was practical and
religious rather than intellectual and theoretical, and whose mental
life, therefore, was more akin to our own than was the highly evolved
culture of the Greeks. Though more remote in time, the wisdom and
practical knowledge of Thebes and Memphis, Nineveh and Babylon, are more
readily comprehended by our minds than the difficult speculations of
Athenian philosophy.
Much that we have inherited from the earliest civilizations is so
familiar, so homely, that we simply accept it, much as we may light, or
air, or water, without analysis, without inquiry as to its origin, and
without full recognition of how indispensable it is. Why are there seven
days in the week, and not eight? Why are there sixty minutes in the
hour, and why are there not sixty hours in the day? These artificial
divisions of time are accepted so unquestioningly that to ask a reason
for them may, to an indolent mind, seem almost absurd. This acceptance
of a week of seven days and of an hour of sixty minutes (almost as if
they were natural divisions of time like day and night) is owing to a
tradition that is Babylonian in its origin. From the Old Testament
(which is one of the greatest factors in preserving the continuity of
human culture, and the only ancient book which speaks with authority
concerning Babylonian history) we learn that Abraham, the progenitor of
the Hebrews, migrated to the west from southern Babylonia about
twenty-three hundred years before Christ. Even in that remote age,
however, the Babylonians had established those divisions of time which
are familiar to us. The seven days of the week were closely associated
in men's thinking with the heavenly bodies. In our modern languages they
are named after the sun, the moon, Mars, Mercury, Jupiter, Venus, and
Saturn, which from the remotest times were personified and worshiped.
Thus we see that the usage of making seven days a unit of time depends
on the religious belief and astronomical science of a very remote
civilization. The usage is so completely established that by the
majority it is simply taken for granted.
Another piece of commonplace knowledge--the cardinal points of the
compass--may be accepted, likewise, without inquiry or without
recognition of its importance. Unless thrown on your own resources in an
unsettled country or on unknown waters, you may long fail to realize how
indispensable to the practical conduct of life is the knowledge of east
and west and north and south. In this matter, again, the records of
ancient civilizations show the pains that were taken to fix these
essentials of science. Modern excavations have demonstrated that the
sides or the corners of the temples and palaces of Assyria and Babylonia
were directed to the four cardinal points of the compass. In Egypt the
pyramids, erected before 3000 B.C., were laid out with such strict
regard to direction that the conjecture has been put forward that their
main purpose was to establish, in a land of shifting sands, east and
west and north and south. That conjecture seems extravagant; but the
fact that the Phœnicians studied astronomy merely because of its
practical value in navigation, the early invention of the compass in
China, the influence on discovery of the later improvements of the
compass, make us realize the importance of the alleged purpose of the
pyramids. Without fixed points, without something to go by, men, before
they had acquired the elements of astronomy, were altogether at sea. As
they advanced in knowledge they looked to the stars for guidance,
especially to the pole star and the imperishable star-group of the
northern heavens. The Egyptians even developed an apparatus for telling
the time by reference to the stars--a star-clock similar in its purpose
to the sundial. By the Egyptians, also, was carefully observed the
season of the year at which certain stars and constellations were
visible at dawn. This was of special importance in the case of Sirius,
for its heliacal rising, that is, the period when it rose in conjunction
with the sun, marked the coming of the Nile flood (so important in the
lives of the inhabitants) and the beginning of a new year. Not
unnaturally Sirius was an object of worship. One temple is said to have
been so constructed as to face that part of the eastern horizon at which
this star arose at the critical season of inundation. Of another temple
we are told that only at sunset at the time of the summer solstice did
the sun throw its rays throughout the edifice. The fact that astronomy
in Egypt as in Babylonia, where the temples were observatories, was
closely associated with religion confirms the view that this science was
first cultivated because of its bearing on the practical needs of the
people. The priests were the preservers of such wisdom as had been
accumulated in the course of man's immemorial struggle with the forces
of nature.
It is well known that geometry had its origin in the valley of the Nile,
that it arose to meet a practical need, and that it was in the first
place, as its name implies, a measurement of the earth--a crude
surveying, employed in the restoration of boundaries obliterated by the
annual inundations of the river. Egyptian geometry cared little for
theory. It addressed itself to actual problems, such as determining the
area of a square or triangular field from the length of the sides. To
find the area of a circular field, or floor, or vessel, from the length
of the diameter was rather beyond the science of 2000 B.C. This was,
however, a practical problem which had to be solved, even if the
solution were not perfect. The practice was to square the diameter
reduced by one ninth.
In all the Egyptian mathematics of which we have record there is to be
observed a similar practical bent. In the construction of a temple or a
pyramid not merely was it necessary to have regard to the points of the
compass, but care must be taken to have the sides at right angles. This
required the intervention of specialists, expert "rope-fasteners," who
laid off a triangle by means of a rope divided into three parts, of
three, four, and five units. The Babylonians followed much the same
practice in fixing a right angle. In addition they learned how to bisect
and trisect the angle. Hence we see in their designs and ornaments the
division of the circle into twelve parts, a division which does not
appear in Egyptian ornamentation till after the incursion of Babylonian
influence.
There is no need, however, to multiply examples; the tendency of all
Egyptian mathematics was, as already stated, concerned with the
practical solution of concrete problems--mensuration, the cubical
contents of barns and granaries, the distribution of bread, the amounts
of food required by men and animals in given numbers and for given
periods of time, the proportions and the angle of elevation (about 52°)
of a pyramid, etc. Moreover, they worked simple equations involving one
unknown, and had a hieroglyph for a million (the drawing of a man
overcome with wonder), and another for ten million.
The Rhind mathematical papyrus in the British Museum is the main source
of our present knowledge of early Egyptian arithmetic, geometry, and of
what might be called their trigonometry and algebra. It describes itself
as "Instructions for arriving at the knowledge of all things, and of
things obscure, and of all mysteries." It was copied by a priest about
1600 B.C.--the classical period of Egyptian culture--from a document
seven hundred years older.
[Illustration: EARLIEST PICTURE KNOWN OF A SURGICAL OPERATION. EGYPT,
2500 B.C.]
Medicine, which is almost certain to develop in the early history of a
people in response to their urgent needs, has been justly called the
foster-mother of many sciences. In the records of Egyptian medical
practice can be traced the origin of chemistry, anatomy, physiology, and
botany. Our most definite information concerning Egyptian medicine
belongs to the same general period as the mathematical document to which
we have just referred. It is true something is known of remoter times.
The first physician of whom history has preserved the name, I-em-hetep
(He-who-cometh-in-peace), lived about 4500 B.C. Recent researches have
also brought to light, near Memphis, pictures, not later than 2500 B.C.,
of surgical operations. They were found sculptured on the doorposts at
the entrance to the tomb of a high official of one of the Pharaohs. The
patients, as shown in the accompanying illustration, are suffering pain,
and, according to the inscription, one cries out, "Do this [and] let me
go," and the other, "Don't hurt me so!" Our most satisfactory data in
reference to Egyptian medicine are derived, however, from the Ebers
papyrus. This document displays some little knowledge of the pulse in
different parts of the body, of a relation between the heart and the
other organs, and of the passage of the breath to the lungs (and heart).
It contains a list of diseases. In the main it is a collection of
prescriptions for the eyes, ears, stomach, to reduce tumors, effect
purgation, etc. There is no evidence of a tendency to homeopathy, but
mental healing seems to have been called into play by the use of
numerous spells and incantations. Each prescription, as in medical
practice to-day, contains as a rule several ingredients. Among the seven
hundred recognized remedies are to be noted poppy, castor-oil, gentian,
colchicum, squills, and many other familiar medicinal plants, as well as
bicarbonate of soda, antimony, and salts of lead and copper. The fat of
the lion, hippopotamus, crocodile, goose, serpent, and wild goat, in
equal parts, served as a prescription for baldness. In the interests of
his art the medical practitioner ransacked the resources of organic and
inorganic nature. The Ebers papyrus shows that the Egyptians knew of the
development of the beetle from the egg, of the blow-fly from the larva,
and of the frog from the tadpole. Moreover, for precision in the use of
medicaments weights of very small denominations were employed.
The Egyptian embalmers relied on the preservative properties of common
salt, wine, aromatics, myrrh, cassia, etc. By the use of linen smeared
with gum they excluded all putrefactive agencies. They understood the
virtue of extreme dryness in the exercise of their antiseptic art. Some
knowledge of anatomy was involved in the removal of the viscera, and
much more in a particular method they followed in removing the brain.
In their various industries the Egyptians made use of gold, silver,
bronze (which on analysis is found to consist of copper, tin, and a
trace of lead, etc.), metallic iron and copper and their oxides,
manganese, cobalt, alum, cinnabar, indigo, madder, brass, white lead,
lampblack. There is clear evidence that they smelted iron ore as early
as 3400 B.C. maintaining a blast by means of leather tread-bellows. They
also contrived to temper the metal, and to make helmets, swords,
lance-points, ploughs, tools, and other implements of iron. Besides
metallurgy they practiced the arts of weaving, dyeing, distillation.
They produced soap (from soda and oil), transparent and colored glass,
enamel, and ceramics. They were skilled in the preparation of leather.
They showed aptitude for painting, and for the other fine arts. They
were expert builders, and possessed the engineering skill to erect
obelisks weighing hundreds of tons. They cultivated numerous vegetables,
grains, fruits, and flowers. They had many domestic animals. In seeking
the satisfaction of their practical needs they laid the foundation of
geometry, botany, chemistry (named, as some think, from the Egyptian
Khem, the god of medicinal herbs), and other sciences. But their
practical achievements far transcended their theoretical formulations.
To all time they will be known as an artistic, noble, and religious
people, who cherished their dead and would not allow that the good and
beautiful and great should altogether pass away.
Excavations in Assyria and Babylonia, especially since 1843, have
brought to our knowledge an ancient culture stretching back four or five
thousand years before the beginning of the Christian era. The records of
Assyria and Babylonia, like those of Egypt, are fragmentary and still in
need of interpretation. Here again, however, it is the fundamental, the
indispensable, the practical forms of knowledge that stand revealed
rather than the theoretical, speculative, and purely intellectual.
By the Babylonian priests the heavens were made the object of expert
observation as early as 3800 B.C. The length of the year, the length of
the month, the coming of the seasons, the course of the sun in the
heavens, the movements of the planets, the recurrence of eclipses,
comets, and meteors, were studied with particular care. One motive was
the need of a measurement of time, the same motive as underlies the
common interest in the calendar and almanac. It was found that the year
contained more than 365 days, the month (synodic) more than 29 days, 12
hours, and 44 minutes. The sun's apparent diameter was contained 720
times in the ecliptic, that is, in the apparent path of the sun through
the heavens. Like the Egyptians, the Babylonians took special note of
the stars and star-groups that were to be seen at dawn at different
times of the year. These constellations, lying in the imaginary
belt encircling the heavens on either side of the ecliptic, bore
names corresponding to those we have adopted for the signs of the
zodiac,--Balance, Ram, Bull, Twins, Scorpion, Archer, etc. The
Babylonian astronomers also observed that the successive vernal (or
autumnal) equinoxes follow each other at intervals of a few seconds
less than a year.
A second motive that influenced the Babylonian priests in studying the
movements of the heavenly bodies was the hope of foretelling events. The
planets, seen to shift their positions with reference to the other
heavenly bodies, were called messengers, or angels. The appearance of
Mars, perhaps on account of its reddish color, was associated in their
imaginations with war. Comets, meteors, and eclipses were considered as
omens portending pestilence, national disaster, or the fate of kings.
The fortunes of individuals could be predicted from a knowledge of the
aspect of the heavens at the hour of their birth. This interest in
astrology, or divination by means of the stars, no doubt stimulated the
priests to make careful observations and to preserve religiously the
record of astronomical phenomena. It was even established that there is
a cycle in which eclipses, solar and lunar, repeat themselves, a period
(_saros_) somewhat more than eighteen years and eleven months. Moreover,
from the Babylonians we derive some of our most sublime religious and
scientific conceptions. They held that strict law governs the apparently
erratic movements of the heavenly bodies. Their creation myth proclaims:
"Merodach next arranged the stars in order, along with the sun and moon,
and gave them laws which they were never to transgress."
The mathematical knowledge of the Babylonians is related on the one hand
to their astronomy and on the other to their commercial pursuits. They
possessed highly developed systems of measuring, weighing, and
counting--processes, which, as we shall see in the sequel, are essential
to scientific thought. About 2300 B.C. they had multiplication tables
running from 1 to 1350, which were probably used in connection with
astronomical calculations. Unlike the Egyptians they had no symbol for a
million, though the "ten thousand times ten thousand" of the Bible
(Daniel VII: 10) may indicate that the conception of even larger numbers
was not altogether foreign to them. They counted in sixties as well as
in tens. Their hours and minutes had each sixty subdivisions. They
divided the circle into six parts and into six-times-sixty subdivisions.
Tables of squares and cubes discovered in southern Babylonia were
interpreted correctly only on a sexagesimal basis, the statement that 1
plus 4 is the square of 8 implying that the first unit is 60. As we have
already seen, considerable knowledge of geometry is apparent in
Babylonian designs and constructions.
According to a Greek historian of the fifth century B.C., there were no
physicians at Babylon, while a later Greek historian (of the first
century B.C.) speaks of a Babylonian university which had attained
celebrity, and which is now believed to have been a school of medicine.
Modern research has made known letters by a physician addressed to an
Assyrian king in the seventh century B.C. referring to the king's chief
physician, giving directions for the treatment of a bleeding from the
nose from which a friend of the prince was suffering, and reporting the
probable recovery of a poor fellow whose eyes were diseased. Other
letters from the same general period mention the presence of physicians
at court. We have even recovered the name (Ilu-bani) of a physician who
lived in southern Babylonia about 2700 B.C. The most interesting
information, however, in reference to Babylonian medicine dates from the
time of Hammurabi, a contemporary of the patriarch Abraham. It appears
from the code drawn up in the reign of that monarch that the Babylonian
surgeons operated in case of cataract; that they were entitled to twenty
silver shekels (half the sum for which Joseph was sold into slavery, and
equivalent to seven or eight dollars) for a successful operation; and
that in case the patient lost his life or his sight as the result of an
unsuccessful operation, the surgeon was condemned to have his hands
amputated.
The Babylonian records of medicine like those of astronomy reveal the
prevalence of many superstitious beliefs. The spirits of evil bring
maladies upon us; the gods heal the diseases that afflict us. The
Babylonian books of medicine contained strange interminglings of
prescription and incantation. The priests studied the livers of
sacrificial animals in order to divine the thoughts of the gods--a
practice which stimulated the study of anatomy. The maintenance of state
menageries no doubt had a similar influence on the study of the natural
history of animals.
The Babylonians were a nation of agriculturists and merchants. Sargon of
Akkad, who founded the first Semitic empire in Asia (3800 B.C.), was
brought up by an irrigator, and was himself a gardener. Belshazzar, the
son of the last Babylonian king, dealt in wool on a considerable scale.
Excavation in the land watered by the Tigris and Euphrates tells the
tale of the money-lenders, importers, dyers, fullers, tanners,
saddlers, smiths, carpenters, shoemakers, stonecutters, ivory-cutters,
brickmakers, porcelain-makers, potters, vintners, sailors, butchers,
engineers, architects, painters, sculptors, musicians, dealers in rugs,
clothing and fabrics, who contributed to the culture of this great
historic people. It is not surprising that science should find its
matrix in so rich a civilization.
The lever and the pulley, lathes, picks, saws, hammers, bronze
operating-lances, sundials, water-clocks, the gnomon (a vertical pillar
for determining the sun's altitude) were in use. Gem-cutting was highly
developed as early as 3800 B.C. The Babylonians made use of copper
hardened with antimony and tin, lead, incised shells, glass, alabaster,
lapis-lazuli, silver, and gold. Iron was not employed before the period
of contact with Egyptian civilization. Their buildings were furnished
with systems of drains and flushes that seem to us altogether modern.
Our museums are enriched by specimens of their handicraft--realistic
statuary in dolerite of 2700 B.C.; rock crystal worked to the form of a
plano-convex lens, 3800 B.C.; a beautiful silver vase of the period 3950
B.C.; and the head of a goat in copper about 4000 B.C.
Excavation has not disclosed nor scholarship interpreted the full record
of this ancient people in the valley of the Tigris and the Euphrates,
not far from the Gulf of Persia, superior in religious inspiration, not
inferior in practical achievements to the Egyptians. Both these great
nations of antiquity, however, failed to carry the sciences that arose
in connection with their arts to a high degree of generalization. That
was reserved for another people of ancient times, namely, the Greeks.
REFERENCES
F. H. Garrison, _An Introduction to the History of Medicine_.
H. V. Hilprecht, _Excavations in Assyria and Babylonia_.
Max Neuburger, _History of Medicine_.
A. H. Sayce, _Babylonians and Assyrians_.
CHAPTER II
THE INFLUENCE OF ABSTRACT THOUGHT--GREECE: ARISTOTLE
No sooner did the Greeks turn their attention to the sciences which had
originated in Egypt and Babylonia than the characteristic intellectual
quality of the Hellenic genius revealed itself. Thales (640-546 B.C.),
who is usually regarded as the first of the Greek philosophers, was the
founder of Greek geometry and astronomy. He was one of the seven "wise
men" of Greece, and might be called the Benjamin Franklin of antiquity,
for he was interested in commerce, famous for political sagacity, and
honored for his disinterested love of general truth. His birthplace was
Miletus, a Greek city on the coast of Asia Minor. There is evidence that
he acquired a knowledge of Babylonian astronomy. The pursuit of commerce
carried him to Egypt, and there he gained a knowledge of geometry. Not
only so, but he was able to advance this study by generalizing and
formulating its truths. For the Egyptians, geometry was concerned with
surfaces and dimensions, with areas and cubical contents; for the Greek,
with his powers of abstraction, it became a study of line and angle. For
example, Thales saw that the angles at the base of an isosceles triangle
are equal, and that when two straight lines cut one another the
vertically opposite angles are equal. However, after having established
general principles, he showed himself capable of applying them to the
solution of particular problems. In the presence of the Egyptian
priests, to which class he was solely indebted for instruction, Thales
demonstrated a method of measuring the height of a pyramid by reference
to its shadow. And again, on the basis of his knowledge of the relation
of the sides of a triangle to its angles, he developed a practical rule
for ascertaining the distance of a ship from the shore.
The philosophical mind of Thales laid hold, no doubt, of some of the
essentials of astronomical science. The particulars usually brought
forward to prove his originality tend rather to show his indebtedness to
the Babylonians. The number of days in the year, the length of the
synodic month, the relation of the sun's apparent diameter to the
ecliptic, the times of recurrence of eclipses, were matters that had
long been known to the Babylonians, as well as to the Chinese. However,
he aroused great interest in astronomy among the Greeks by the
prediction of a solar eclipse. This was probably the eclipse of 585
B.C., which interrupted a fierce battle between the Medes and the
Lydians. The advice of Thales to mariners to steer by the Lesser Bear,
as nearer the pole, rather than by the Great Bear, shows also that in
his astronomical studies as in his geometrical he was not indifferent to
the applications of scientific knowledge.
In fact, some writers maintain that Thales was not a philosopher at all,
but rather an astronomer and engineer. We know very little of his purely
speculative thought. We do know, however, that he arrived at a
generalization--fantastic to most minds--that all things are water.
Attempts have been made to add to this statement, and to explain it
away. Its great interest for the history of thought lies in the fact
that it is the result of seeking the constant in the variable, the
unitary principle in the multiple phenomena of nature. This abstract and
general view (though perhaps suggested by the Babylonian belief that the
world originated in a watery chaos, or by the teaching of Egyptian
priests) was preëminently Greek, and was the first of a series of
attempts to discover the basis or origin of all things. One of the
followers of Thales taught that air was the fundamental principle; while
Heraclitus, anticipating to some extent modern theories of the origin of
the cosmos, declared in favor of a fiery vapor subject to ceaseless
change. Empedocles, the great philosopher-physician, first set forth the
doctrine of the four _elements_--earth, air, fire, and water. For
Democritus indivisible particles or atoms are fundamental to all
phenomena. It is evident that the theory of Thales was a starting point
for Greek abstract thought, and that his inclination to seek out
principles and general laws accounts for his influence on the
development both of philosophy and the sciences.
Pythagoras, on the advice of Thales, visited Egypt in the pursuit of
mathematics. There is reason to believe that he also visited Babylonia.
For him and his followers mathematics became a philosophy--almost a
religion. They had discovered (by experimenting with the monochord, the
first piece of physical-laboratory apparatus, consisting of a tense
harpstring with a movable bridge) the effect on the tone of the string
of a musical instrument when the length is reduced by one half, and also
that strings of like thickness and under equal tension yield harmonious
tones when their lengths are related as 1:2, 2:3, 3:4, 4:5. The
Pythagoreans drew from this the extravagant inference that the heavenly
bodies would be in distance from the earth as 1, 2, 3, 4, 5, etc. Much
of their theory must seem to the modern mind merely fanciful and
unsupported speculation. At the same time it is only just to this school
of philosophers to recognize that their assumption that simple
mathematical relationships govern the phenomena of nature has had an
immense influence on the advance of the sciences. Whether their
fanaticism for number was owing to the influence of Egyptian priests or
had an Oriental origin, it gave to the Pythagoreans an enthusiasm for
pure mathematics. They disregarded the bearing of their science on the
practical needs of life. Old problems like squaring the circle,
trisecting the angle, and doubling the cube, were now attempted in a new
spirit and with fresh vigor. The first, second, and fourth books of
Euclid are largely of Pythagorean origin. For solid geometry as a
science we are also indebted to this sect of number-worshipers. One of
them (Archytas, 428-347 B.C., a friend of Plato) was the first to apply
geometry to mechanics. We see again here, as in the case of Thales, that
the love of abstract thought, the pursuit of science as science, did not
interfere with ultimate practical applications.
Plato (429-347 B.C.), like many other Greek philosophers, traveled
extensively, visiting Asia Minor, Egypt, and Lower Italy, where
Pythagorean influence was particularly strong. His chief interest lay in
speculation. For him there were two worlds, the world of sense and the
world of ideas. The senses deceive us; therefore, the philosopher should
turn his back upon the world of sensible impressions, and develop the
reason. In his _Dialogues_ he outlined a course of training and study,
the professed object of which was to educate a class of philosophers.
(Strange to say, Plato's curriculum, planned originally for the
intellectual _élite_, still dictates in our schools the education of
millions of boys and girls whose careers do not call for a training
merely of the reason.)
Over the porch of his school, the Academy at Athens, were inscribed the
words, "Let no one who is unacquainted with geometry enter here." It was
not because it was useful in everyday life that Plato laid such
insistence on this study, but because it increased the students' powers
of abstraction and trained the mind to correct and vigorous thinking.
From his point of view the chief good of geometry is lost unless we can
through it withdraw the mind from the particular and the material. He
delighted in clearness of conception. His main scientific interest was
in astronomy and mathematics. We owe to him the definition of a line as
"length without breadth," and the formulation of the axiom, "Equals
subtracted from equals leave equals."
Plato had an immediate influence in stimulating mathematical studies,
and has been called a maker of mathematicians. Euclid, who was active at
Alexandria toward the end of the fourth century B.C., was not one of
Plato's immediate disciples but shared the great philosopher's point of
view. The story is told that one of his pupils, arrived perhaps at the
_pons asinorum_, asked, "What do I get by learning these things?"
Euclid, calling his servant, said, "Give him sixpence, since he must
make gain out of what he learns." Adults were also found, even among the
nimble-witted Greeks, to whom abstract reasoning was not altogether
congenial. This is attested by the familiar story of Ptolemy, King of
Egypt, who once asked Euclid whether geometry could not be learned in
some easier way than by studying the geometer's book, _The Elements_. To
this the schoolmaster replied, "There is no royal road to geometry." For
the academic intelligence abstract and abstruse mathematics are tonic
and an end in themselves. As already stated, their ultimate practical
value is also immense. One of Plato's associates, working under his
direction, investigated the curves produced by cutting cones of
different kinds in a certain plane. These curves--the ellipse, the
parabola, the hyperbola--play a large part in the subsequent history of
astronomy and mechanics. Another Platonist made the first measurement of
the earth's circumference.
Aristotle, the greatest pupil of Plato, was born at Stagira in 384 B.C.
He came of a family of physicians, was trained for the medical
profession, and had his attention early directed to natural phenomena.
He entered the Academy at Athens about 367 B.C., and studied there till
the death of Plato twenty years later. He was a diligent but, as was
natural, considering the character of his early education, by no means a
passive student. Plato said that Aristotle reacted against his
instructor as a vigorous colt kicks the mother that nourishes it. The
physician's son did not accept without modification the view that the
philosopher should turn his back upon the things of sense. He had been
trained in the physical science of the time, and believed in the reality
of concrete things. At the same time he absorbed what he found of value
in his master's teachings. He thought that science did not consist in a
mere study of individual things, but that we must pass on to a
formulation of general principles and then return to a study of the
concrete. His was a great systematizing intellect, which has left its
imprint on nearly every department of knowledge. Physical astronomy,
physical geography, meteorology, physics, chemistry, geology, botany,
anatomy, physiology, embryology, and zoölogy were enriched by his
teaching. It was through him that logic, ethics, psychology, rhetoric,
æsthetics, political science, zoölogy (especially ichthyology), first
received systematic treatment. As a great modern philosopher has said,
Aristotle pressed his way through the mass of things knowable, and
subjected its diversity to the power of his thought. No wonder that for
ages he was known as "The Philosopher," master of those who know. His
purpose was to comprehend, to define, to classify the phenomena of
organic and inorganic nature, to systematize the knowledge of his own
time.
Twenty years' apprenticeship in the school of Plato had sharpened his
logical powers and added to his stock of general ideas, but had not
taught him to distrust his senses. When we say that our eyes deceive us,
we really confess that we have misinterpreted the data that our sight
has furnished. Properly to know involves the right use of the senses as
well as the right use of reason. The advance of science depends on the
development both of speculation and observation. Aristotle advised
investigators to make sure of the facts before seeking the explanation
of the facts. Where preconceived theory was at variance with observed
facts, the former must of course give way. Though it has been said that
while Plato was a dreamer, Aristotle was a thinker, yet it must be
acknowledged in qualification that Plato often showed genuine knowledge
of natural phenomena in anatomy and other departments of study, and that
Aristotle was carried away at times by his own presuppositions, or
failed to bring his theories to the test of observation. The Stagirite
held that the velocity of falling bodies is proportional to their
weight, that the function of the diaphragm is to divide the region of
the nobler from that of the animal passions, and that the brain is
intended to act in opposition to the heart, the brain being formed of
earthy and watery material, which brings about a cooling effect. The
theory of the four elements--the hot, the cold, the moist, the dry--led
to dogmatic statements with little attempt at verification. From the
standpoint of modern studies it is easy to point out the mistakes of
Aristotle even. Science is progressive, not infallible.
In his own time he was rather reproached for what was considered an
undignified and sordid familiarity with observed facts. His critics said
that having squandered his patrimony, he had served in the army, and,
failing there, had become a _seller of drugs_. His observations on the
effects of heat seem to have been drawn from the common processes of the
home and the workshop. Even in the ripening of fruits heat appears to
him to have a cooking effect. Heat distorts articles made of potters'
clay after they have been hardened by cold. Again we find him describing
the manufacture of potash and of steel. He is not disdainful of the
study of the lower animals, but invites us to investigate all forms in
the expectancy of discovering something natural and beautiful. In a
similar spirit of scientific curiosity the Aristotelian work _The
Problems_ studies the principle of the lever, the rudder, the wheel and
axle, the forceps, the balance, the beam, the wedge, as well as other
mechanical principles.
In Aristotle, in fact, we find a mind exceptionally able to form clear
ideas, and at the same time to observe the rich variety of nature. He
paid homage both to the multiplicity and the uniformity of nature, the
wealth of the phenomena and the simplicity of the law explaining the
phenomena. Many general and abstract ideas (category, energy,
entomology, essence, mean between extremes, metaphysics, meteorology,
motive, natural history, principle, syllogism) have through the
influence of Aristotle become the common property of educated people the
world over.
Plato was a mathematician and an astronomer. Aristotle was first and
foremost a biologist. His books treated the history of animals, the
parts of animals, the locomotion of animals, the generation of animals,
respiration, life and death, length and shortness of life, youth and old
age. His psychology is, like that of the present day, a biological
psychology. In his contributions to biological science is manifested
his characteristic inclination to be at once abstract and concrete. His
works display a knowledge of over five hundred living forms. He
dissected specimens of fifty different species of animals. One might
mention especially his minute knowledge of the sea-urchin, of the murex
(source of the famous Tyrian dye), of the chameleon, of the habits of
the torpedo, the so-called fishing-frog, and nest-making fishes, as well
as of the manner of reproduction of whales and certain species of
sharks. One of his chief contributions to anatomy is the description of
the heart and of the arrangement of the blood-vessels. A repugnance to
the dissection of the human body seems to have checked to some extent
his curiosity in reference to the anatomy of man, but he was acquainted
with the structure of the internal ear, the passage leading from the
pharynx to the middle ear, and the two outer membranes of the brain of
man. Aristotle's genius did not permit him to get lost in the mere
details of observed phenomena. He recognized resemblances and
differences between the various species, classified animals as belonging
to two large groups, distinguished whales and dolphins from fishes,
recognized the family likeness of the domestic pigeon, the wood pigeon,
the rock pigeon, and the turtle dove. He laid down the characteristics
of the class of invertebrates to which octopus and sepia belong. Man
takes a place in Aristotle's system of nature as a social animal, the
highest type of the whole series of living beings, characterized by
certain powers of recall, reason, deliberation. Of course it was not to
be expected that Aristotle should work out a fully satisfactory
classification of all the varieties of plants and animals known to him.
Yet his purpose and method mark him as the father of natural science. He
had the eye to observe and the mind to grasp the relationships and the
import of what he observed. His attempt to classify animals according to
the nature of their teeth (dentition) has been criticized as
unsuccessful, but this principle of classification is still of use,
and may be regarded as typical of his mind, at once careful and
comprehensive.
One instance of Aristotle's combining philosophical speculation with
acute observation of natural phenomena is afforded by his work on
generation and development. He knew that the transmission of life
deserves special study as the predominant function of the various
species of plants and animals. Deformed parents may have well-formed
offspring. Children may resemble grandparents rather than parents. It is
only toward the close of its development that the embryo exhibits the
characteristics of its parent species. Aristotle traced with some care
the embryological development of the chick from the fourth day of
incubation. His knowledge of the propagation of animals was, however,
not sufficient to make him reject the belief in spontaneous generation
from mud, sand, foam, and dew. His errors are readily comprehensible,
as, for example, in attributing spontaneous generation to eels, the
habits and mode of reproduction of which only recent studies have made
fully known. In regard to generation, as in other scientific fields, the
philosophic mind of Aristotle anticipated modern theories, and also
raised general questions only to be solved by later investigation of the
facts.
Only one indication need be given of the practical results that flowed
from Aristotle's scientific work. In one of his writings he has stated
that the sphericity of the earth can be observed from the fact that its
shadow on the moon at the time of eclipse is an arc. That it is both
spherical and small in comparison with the heavenly bodies appears,
moreover, from this, that stars visible in Egypt are invisible in
countries farther north; while stars always above the horizon in
northern countries are seen to set from countries to the south.
Consequently the earth is not only spherical but also not large;
otherwise this phenomenon would not present itself on so limited a
change of position on the part of the observer. "It seems, therefore,
not incredible that the region about the Pillars of Hercules [Gibraltar]
is connected with that of India, and that there is thus only one ocean."
It is known that this passage from _The Philosopher_ influenced Columbus
in his undertaking to reach the Orient by sailing west from the coast of
Spain.
We must pass over Aristotle's observation of a relationship (homology)
between the arms of man, the forelegs of quadrupeds, the wings of birds,
and the pectoral fins of fishes, as well as many other truths to which
his genius for generalization led him.
In the field of botany Aristotle had a wide knowledge of natural
phenomena, and raised general questions as to mode of propagation,
nourishment, relation of plants to animals, etc. His pupil and lifelong
friend, and successor as leader of the Peripatetic school of philosophy,
Theophrastus, combined a knowledge of mathematics, astronomy, botany,
and mineralogy. His _History of Plants_ describes about five hundred
species. At the same time he treats the general principles of botany,
the distribution of plants, the nourishment of the plant through leaf as
well as root, the sexuality of date palm and terebinth. He lays great
stress on the uses of plants. His classification of plants is inferior
to Aristotle's classification of animals. His views in reference to
spontaneous generation are more guarded than those of his master. His
work _On Stones_ is dominated by the practical rather than the
generalizing spirit. It is evidently inspired by a knowledge of mines,
such as the celebrated Laurium, from which Athens drew its supply of
silver, and the wealth from which enabled the Athenians to develop a
sea-power that overmatched that of the Persians. Even to-day enough
remains of the galleries, shafts, scoria, mine-lamps, and other utensils
to give a clear idea of this scene of ancient industry. Theophrastus
considered the medicinal uses of minerals as well as of plants.
We have failed to mention Hippocrates (460-370 B.C.), the Father of
Medicine, in whom is found an intimate union of practical science and
speculative philosophy. We must also pass over such later Greek
scientists as Aristarchus and Hipparchus who confuted the theories of
Pythagoras and Plato in reference to the relative distances of the
heavenly bodies from the earth. Archimedes of Syracuse demands, however,
particular consideration. He lived in the third century B.C., and has
been called the greatest mathematician of antiquity. In him we find the
devotion to the abstract that marked the Greek intelligence. He went so
far as to say that every kind of art is ignoble if connected with daily
needs. His interest lay in abstruse mathematical problems. His special
pride was in having determined the relative dimensions of the sphere and
the enclosing cylinder. He worked out the principle of the lever. "Give
me," he said, "a place on which to stand and I will move the earth." He
approximated more closely than the Egyptians the solution of the problem
of the relation between the area of a circle and the radius. His work
had practical value in spite of himself. At the request of his friend
the King of Sicily, he applied his ingenuity to discover whether a
certain crown were pure gold or alloyed with silver, and he hit upon a
method which has found many applications in the industries. His name is
associated with the endless screw. In fact, his practical contrivances
won such repute that it is not easy to separate the historical facts
from the legends that enshroud his name. He aided in the defense of his
native city against the Romans in 212 B.C., and devised war-engines with
which to repel the besiegers. After the enemy had entered the city, says
tradition, he stood absorbed in a mathematical problem which he had
diagrammed on the sand. As a rude Roman soldier approached, Archimedes
cried, "Don't spoil my circles," and was instantly killed. The
victorious general, however, buried him with honor, and on the tomb of
the mathematician caused to be inscribed the sphere with its enclosing
cylinder. The triumphs of Greek abstract thought teach the lesson that
practical men should pay homage to speculation even when they fail to
comprehend a fraction of it.
REFERENCES
Aristotle, _Historia Animalium_; translated by D'A. W. Thompson. (Vol.
IV of the _Works of Aristotle Translated into English_. Oxford:
Clarendon Press.)
A. B. Buckley (Mrs. Buckley Fisher), _A Short History of Natural
Science_.
G. H. Lewes, _Aristotle; A Chapter in the History of Science_.
T. E. Lones, _Aristotle's Researches in Natural Science_.
D'A. W. Thompson, _On Aristotle as a Biologist_.
William Whewell, _History of the Inductive Sciences_.
Alfred Weber, _History of Philosophy_.
CHAPTER III
SCIENTIFIC THEORY SUBORDINATED TO APPLICATION--ROME: VITRUVIUS
Vitruvius was a cultured engineer and architect. He was employed in the
service of the Roman State at the time of Augustus, shortly before the
beginning of the Christian era. He planned basilicas and aqueducts, and
designed powerful war-engines capable of hurling rocks weighing three or
four hundred pounds. He knew the arts and the sciences, held lofty
ideals of professional conduct and dignity, and was a diligent student
of Greek philosophy.
We know of him chiefly from his ten short books on Architecture (_De
Architectura, Libri Decem_), in which he touches upon much of the
learning of his time. Architecture for Vitruvius is a science arising
out of many other sciences. Practice and theory are its parents. The
merely practical man loses much by not knowing the background of his
activities; the mere theorist fails by mistaking the shadow for the
substance. Vitruvius in the theoretical and historical parts of his book
draws largely on Greek writers; but in the parts bearing on practice he
sets forth, with considerable shrewdness, the outcome of years of
thoughtful professional experience. One cannot read his pages without
feeling that he is more at home in the concrete than in the abstract and
speculative, in describing a catapult than in explaining a scientific
theory or a philosophy. He was not a Plato or an Archimedes, but an
efficient officer of State, conscious of indebtedness to the great
scientists and philosophers. With a just sense of his limitations he
undertook to write, not as a literary man, but as an architect. His
education had been mainly professional, but, the whole circle of
learning being one harmonious system, he had been drawn to many branches
of knowledge in so far as they were related to his calling.
In the judgment of Vitruvius an architect should be a good writer, able
to give a lucid explanation of his plans, a skillful draftsman, versed
in geometry and optics, expert at figures, acquainted with history,
informed in the principles of physics and of ethics, knowing something
of music (tones and acoustics), not ignorant of law, or of hygiene, or
of the motions, laws, and relations to each other of the heavenly
bodies. For, since architecture "is founded upon and adorned with so
many different sciences, I am of opinion that those who have not, from
their early youth, gradually climbed up to the summit, cannot without
presumption, call themselves masters of it."
Vitruvius was far from sharing the view of Archimedes that art which was
connected with the satisfaction of daily needs was necessarily ignoble
and vulgar. On the contrary, his interest centered in the practical; and
he was mainly concerned with scientific theory by reason of its
application in the arts. Geometry helped him plan a staircase; a
knowledge of tones was necessary in discharging catapults; law dealt
with boundary-lines, sewage-disposal, and contracts; hygiene enabled the
architect to show a Hippocratic wisdom in the choice of building-sites
with due reference to airs and waters. Vitruvius had the Roman
practical and regulative genius, not the abstract and speculative genius
of Athens.
The second book begins with an account of different philosophical views
concerning the origin of matter, and a discussion of the earliest
dwellings of man. Its real theme, however, is building-material--brick,
sand, lime, stone, concrete, marble, stucco, timber, pozzolano. In
reference to the last (volcanic ash combined with lime and rubble to
form a cement) Vitruvius writes in a way that indicates a discriminating
knowledge of geological formations. Likewise his discussion of the
influence of the Apennines on the rainfall, and, consequently, on the
timber of the firs on the east and west of the range, shows a grasp of
meteorological principles. His real power to generalize is shown in
connection with his specialty, in his treatment of the sources of
building-material, rather than in his consideration of the origin of
matter.
Similarly the fifth book begins with a discussion of the theories of
Pythagoras, but its real topic is public buildings--fora, basilicas,
theaters, baths, palæstras, harbors, and quays. In the theaters bronze
vases of various sizes, arranged according to Pythagorean musical
principles, were to be used in the auditorium to reinforce the voice of
the actor. (This recommendation was misunderstood centuries later, when
Vitruvius was considered of great authority, and led to the futile
practice of placing earthenware jars beneath the floors of church
choirs.) According to our author, "The voice arises from flowing breath,
sensible to the hearing through its percussion on the air." It is
compared to the wavelets produced by a stone dropped in water, only that
in the case of sound the waves are not confined to one plane. This
generalization concerning the nature of sound was probably not original,
however; it may have been suggested to Vitruvius by one of the
Aristotelian writings.
The seventh book treats of interior decoration--mosaic floors, gypsum
mouldings, wall painting, white lead, red lead, verdigris, mercury
(which may be used to recover gold from worn-out pieces of embroidery),
encaustic painting with hot wax, colors (black, blue, genuine and
imitation murex purple). The eighth book deals with water and with
hydraulic engineering, hot springs, mineral waters, leveling
instruments, construction of aqueducts, lead and clay piping. Vitruvius
was not ignorant of the fact that water seeks its own level, and he even
argued that air must have weight in order to account for the rise of
water in pumps. In his time it was more economical to convey the hard
water by aqueducts than by such pipes as could then be constructed. The
ninth book undertakes to rehearse the elements of geometry and
astronomy--the signs of the zodiac, the sun, moon, planets, the phases
of the moon, the mathematical divisions of the gnomon, the use of the
sundial, etc. One feels in reading Vitruvius that his purpose was to
turn to practical account what he had gained from the study of the
sciences; and, at the same time, one is convinced that his applications
tend to react on theoretical knowledge, and lead to new insights through
the suggestion of new problems.
The tenth book of the so-called _De Architectura_ is concerned with
machinery--windmills, windlasses, axles, pulleys, cranes, pumps,
fire-engines, revolving spiral tubes for raising water, wheels for
irrigation worked by water-power, wheels to register distance traveled
by land or water, scaling-ladders, battering-rams, tortoises, catapults,
scorpions, and ballistæ. On the subject of war-engines Vitruvius speaks
with special authority, as he had served, probably as military engineer,
under Julius Cæsar in 46 B.C., and had been appointed superintendent of
ballistæ and other military engines in the time of Augustus. It was to
the divine Emperor that his book was dedicated as a protest against the
administration of Roman public works. In its pages we see reflected the
life of a nation employed in conquering and ruling the world, with a
genius more distinguished for practical achievement than for theory and
speculation. Its author is truly representative of Roman culture, for
nearly everything that Rome had of a scientific and intellectual sort it
drew from Greece, and it selected that part of Greek wisdom that
ministered to the daily needs of the times. In his work on architecture,
Vitruvius shows himself a diligent and devoted student of the sciences
in order that he may turn them to account in his own department of
technology.
If you glance at the study of mathematics, astronomy, and medicine among
the Romans prior to the time of Greek influence, you find that next to
nothing had been accomplished. Their method of field measurement was far
less developed than the ancient Egyptian geometry, and even for it (as
well as for their system of numerals) they were indebted to the
Etruscans. The history of astronomy has nothing to record of scientific
accomplishment on the part of the Romans. They reckoned time by months,
and in the earlier period kept a rude tally of the years by driving
nails into a statue of Janus, the ancient sun-god. As we shall see, they
were unable to regulate the calendar. Again, so far were they from
contributing to the development of medicine that they had no physicians
for the six hundred years preceding the coming of Greek science. A
medical slave acted as overseer of the family health, and disease was
combated in primitive fashion by prayers and offerings to various gods,
who were supposed to furnish general health or to influence the
functions of the different parts of the body. So rude was the native
culture of the Romans that it is doubtful whether they had any schools
before the advent of Greek learning. The girls were trained by their
mothers, the boys either by their fathers or by some master to whom they
were apprenticed.
The Greeks were conquered by the Romans in 146 B.C., but before that
time Roman life and institutions had been touched by Hellenic culture.
Cato the Censor (who died in 149 B.C.) and other conservatives tried in
vain to resist the invasion of Greek science, philosophy, and
refinement. After the conquest of Greece the master became pupil, and
the conqueror was taken captive. The Romans, however, never rose to
preëminence in science or the fine arts. A further development in
technology corresponded more closely to their national needs, and in
this field they came undoubtedly to surpass the Greeks. Bridges, ships,
military roads, war-engines, aqueducts, public buildings, organization
of the State and the army, the formulation of legal procedure, the
enactment and codification of laws, were necessary to secure and
maintain the Empire. The use in building construction of a knowledge of
the right-angled triangle as well as other matters known to the
Egyptians and Babylonians, and Archimedes' method of determining
specific gravity were of peculiar interest to the practical Romans.
Julius Cæsar, 102-44 B.C., instituted a reform of the calendar. This was
very much needed, as the Romans were eighty-five days out of their
reckoning, and the date for the spring equinox, instead of coming at the
proper time, was falling in the middle of winter. An Alexandrian
astronomer (Sosigenes) assisted in establishing the new (Julian)
calendar. The principle followed was based on ancient Egyptian practice.
Among the 365 days of the year was to be inserted, or intercalated,
every fourth year an extra day. This the Romans did by giving to two
days in leap-year the same name; thus the sixth day before the first of
March was repeated, and leap-year was known as a bissextile year. Cæsar,
trained himself in the Greek learning and known to his contemporaries as
a writer on mathematics and astronomy, also planned a survey of the
Empire, which was finally carried into execution by Augustus.
There is evidence that the need of technically trained men became more
and more pressing as the Empire developed. At first there were no
special teachers or schools. Later we find mention of teachers of
architecture and mechanics. Then the State came to provide classrooms
for technical instruction and to pay the salaries of the teachers.
Finally, in the fourth century A.D., further measures were adopted by
the State. The Emperor Constantine writes to one of his officials: "We
need as many engineers as possible. Since the supply is small, induce to
begin this study youths of about eighteen years of age who are already
acquainted with the sciences required in a general education. Relieve
their parents from the payment of taxes, and furnish the students with
ample means."
Pliny the Elder (23-79 A.D.), in the encyclopedic work which he compiled
under the title _Natural History_, drew freely on hundreds of Greek and
Latin authors for his facts and fables. In the selection that he made
from his sources can be traced, as in the work of Vitruvius and other
Latin writers, the tendency to make the sciences subservient to the
arts. For example, the one thousand species of plants of which he makes
mention are considered from the medicinal or from the economic point of
view. It was largely in the interest of their practical uses that the
Roman regarded both plants and animals; his chief motive was not a
disinterested love of truth. Pliny thought that each plant had its
special virtue, and much of his botany is applied botany. So
comprehensive a work as the _Natural History_ was sure to contain
interesting anticipations of modern science. Pliny held that the earth
hovers in the heavens upheld by the air, that its sphericity is proved
by the fact that the mast of a ship approaching the land is visible
before the hull comes in sight. He also taught that there are
inhabitants on the other side of the earth (antipodes), that at the time
of the winter solstice the polar night must last for twenty-four hours,
and that the moon plays a part in the production of the tides.
Nevertheless, the whole book is permeated by the idea that the purpose
of nature is to minister to the needs of man.
It further marks the practical spirit among the Romans that a work on
agriculture by a Carthaginian (Mago) was translated by order of the
Senate. Cato (234-149 B.C.), so characteristically Roman in his genius,
wrote (_De Re Rustica_) concerning grains and the cultivation of fruits.
Columella wrote treatises on agriculture and forestry. Among the
technical writings of Varro besides the book on agriculture, which is
extant, are numbered works on law, mensuration, and naval tactics.
It was but natural that at the time of the Roman Empire there should be
great advances in medical science. A Roman's interest in a science was
keen when it could be proved to have immediate bearing on practical
life. The greatest physician of the time, however, was a Greek. Galen
(131-201 A.D.), who counted himself a disciple of Hippocrates, began to
practice at Rome at the age of thirty-three. He was the only
experimental physiologist before the time of Harvey. He studied the
vocal apparatus in the larynx, and understood the contraction and
relaxation of the muscles, and, to a considerable extent, the motion of
the blood through the heart, lungs, and other parts of the body. He was
a vivisector, made sections of the brain in order to determine the
functions of its parts, and severed the gustatory, optic, and auditory
nerves with a similar end in view. His dissections were confined to the
lower animals. Yet his works on human anatomy and physiology were
authoritative for the subsequent thirteen centuries. It is difficult to
say how much of the work and credit of this practical scientist is to be
given to the race from which he sprang and how much to the social
environment of his professional career. (In the ruins of Pompeii,
destroyed in 79 A.D., have been recovered some two hundred kinds of
surgical instrument, and in the later Empire certain departments of
surgery developed to a degree not surpassed till the sixteenth century.)
If it is too much to say that the Roman environment is responsible for
Galen's achievements, we can at least say that it was characteristic
of the Roman people to welcome such science as his, capable of
demonstrating its utility.
Dioscorides was also a Greek who, long resident at Rome, applied his
science in practice. He knew six hundred different plants, one hundred
more than Theophrastus. The latter laid much stress, as we have seen in
the preceding chapter, on the medicinal properties of plants, but in
this respect he was outdone by Dioscorides (as well as by Pliny).
Theophrastus was the founder of the science of botany, Dioscorides the
founder of materia medica.
Quintilian, born in Spain, spent the greater part of his life as a
teacher of rhetoric in Rome. He valued the sciences, not on their own
account, but as they might subserve the purposes of the orator. Music,
astronomy, logic, and even theology, might be exploited as aids to
public speech. In the time of Quintilian (first century A.D.), as in our
own, oratory was considered one of the great factors in a young man's
success; mock debating contests were frequent, and the periods of the
future orators reverberated among the seven hills of Rome. To him our
schools are also indebted for the method of teaching foreign languages
by declensions, conjugations, vocabularies, formal rhetoric and
annotations. He considered ethics the most valuable part of philosophy.
In fact, it would not be pressing our argument unduly to say that, so
far as the minds of the Romans turned to speculation, it was the
tendency to practical philosophy--Epicureanism or Stoicism--that was
most characteristic. This was true even of Lucretius (98-55 B.C.),
author of the noble poem concerning the Nature of Things (_De Rerum
Natura_). In this work he writes under the inspiration of Greek
philosophy. His model was a poem by Empedocles on Nature, the grand
hexameters of which had fascinated the Roman poet. The distinctive
feature of the work of Lucretius is the purpose, ethical rather than
speculative, to curb the ambition, passion, luxury of those hard pagan
times, and likewise to free the souls of his countrymen from the fear of
the gods and the fear of death, and to replace superstition by peace of
mind and purity of heart.
From the work on Physical Science (_Quæstionum Naturalium, Libri
Septem_) of Seneca, the tutor of Nero, we learn that the Romans made use
of globes filled with water as magnifiers, employed hothouses in their
highly developed horticulture, and observed the refraction of colors by
the prism. At the same time the book contains interesting conjectures in
reference to the relation of earthquakes and volcanoes, and to the fact
that comets travel in fixed orbits. In the main, however, this work is
an attempt to find a basis for ethics in natural phenomena. Seneca was a
Stoic, as Lucretius was an Epicurean, moralist.
When we glance back at the culture, or cultures, of the great peoples of
antiquity, Egyptian, Babylonian, Greek, and Roman, that which had its
center on the banks of the Tiber offers the closest analogy to our own.
Among English-speaking peoples as among the Romans there is noticeable a
certain contempt for scientific studies strangely mingled with an
inclination to exploit all theory in the interest of immediate
application. An English author, writing in 1834, remarks that the
Romans, eminent in war, in polite literature, and civil policy, showed
at all times a remarkable indisposition to the pursuit of mathematical
and physical science. Geometry and astronomy, so highly esteemed by the
Greeks, were not merely disregarded by the Italians, but even considered
beneath the attention of a man of good birth and liberal education; they
were imagined to partake of a mechanical, and therefore servile,
character. "The results were seen to be made use of by the mechanical
artist, and the abstract principles were therefore supposed to be, as it
were, contaminated by his touch. This unfortunate peculiarity in the
taste of his countrymen is remarked by Cicero. And it may not be
irrelevant to inquire, whether similar prejudices do not prevail to some
extent even among ourselves." To Americans also must be attributed an
impatience of theory as theory, and a predominant interest in the
applications of science.
REFERENCES
Lucretius, _The Nature of Things_; translated by H. A. J. Munro.
Pliny, _Natural History_; translated by Philemon Holland.
Professor Baden Powell, _History of Natural Philosophy_.
Seneca, _Physical Science_; translated by John Clarke.
Vitruvius, _Architecture_; translated by Joseph Gwilt, 1826.
Vitruvius, _Architecture_; translated by Professor M. H. Morgan, 1914.
CHAPTER IV
THE CONTINUITY OF SCIENCE--THE MEDIEVAL CHURCH AND THE ARABS
Learning has very often and very aptly been compared to a torch passed
from hand to hand. By the written sign or spoken word it is transmitted
from one person to another. Very little advance in culture could be made
even by the greatest man of genius if he were dependent, for what
knowledge he might acquire, merely on his own personal observation.
Indeed, it might be said that exceptional mental ability involves a
power to absorb the ideas of others, and even that the most original
people are those who are able to borrow the most freely.
In recalling the lives of certain great men we may at first be inclined
to doubt this truth. How shall we account for the part played in the
progress of civilization by the rustic Burns, the village-bred
Shakespeare, or by Lincoln the frontiersman? When, however, we
scrutinize the case of any one of these, we discover, of course,
exceptional natural endowment, susceptibility to mental influence,
remarkable powers of acquisition, but no ability to produce anything
absolutely original. In the case of Lincoln, for example, we find that
in his youth he was as distinguished by diligence in study as by
physical stature and prowess. After he withdrew from school, he read,
wrote, and ciphered (in the intervals of manual work) almost
incessantly. He read everything he could lay hands on. He copied out
what most appealed to him. A few books he read and re-read till he had
almost memorized them. What constituted his library? The Bible, _Æsop's
Fables_, _Robinson Crusoe_, _The Pilgrim's Progress_, a _Life of
Washington_, a _History of the United States_. These established for him
a vital relation with the past, and laid the foundations of a democratic
culture; not the culture of a Chesterfield, to be sure, but something
immeasurably better, and none the less good for being almost universally
accessible. Lincoln developed his logical powers conning the dictionary.
Long before he undertook the regular study of the law, he spent long
hours poring over the revised statutes of the State in which he was
living. From a book he mastered with a purpose the principles of
grammar. In the same spirit he learned surveying, also by means of a
book. There is no need to ignore any of the influences that told
toward the development of this great statesman, the greatest of
English-speaking orators, but it is evident that remote as was his
habitation from all the famous centers of learning he was, nevertheless,
early immersed in the current of the world's best thought.
Similarly, in the history of science, every great thinker has his
intellectual pedigree. Aristotle was the pupil of Plato, Plato was the
disciple of Socrates, and the latter's intellectual genealogy in turn
can readily be traced to Thales, and beyond--to Egyptian priests and
Babylonian astronomers.
The city of Alexandria, founded by the pupil of Aristotle in 332 B.C.,
succeeded Athens as the center of Greek culture. On the death of
Alexander the Great, Egypt was ruled by one of his generals, Ptolemy,
who assumed the title of king. This monarch, though often engaged in
war, found time to encourage learning, and drew to his capital scholars
and philosophers from Greece and other countries. He wrote himself a
history of Alexander's campaigns, and instituted the famous library of
Alexandria. This was greatly developed (and supplemented with schools of
science and an observatory) by his son Ptolemy Philadelphus, a prince
distinguished by his zeal in promoting the good of the human species. He
collected vast numbers of manuscripts, had strange animals brought from
distant lands to Alexandria, and otherwise promoted scientific research.
This movement was continued under Ptolemy III (246-221 B.C.).
Something has already been said of the early astronomers and
mathematicians of Alexandria. The scientific movement of the later
Alexandrian period found its consummation in the geographer, astronomer,
and mathematician Claudius Ptolemy (not to be confused with the rulers
of that name). He was most active 127-151 A.D., and is best known by his
work the _Syntaxis_, which summarized what was known in astronomy at
that time. Ptolemy drew up a catalogue of 1080 stars based on the
earlier work of Hipparchus. He followed that astronomer in teaching that
the earth is the center of the movement of the heavenly bodies, and this
geocentric system of the heavens became known as the Ptolemaic system of
astronomy. To Hipparchus and Ptolemy we owe also the beginnings of the
science of trigonometry. The _Syntaxis_ sets forth his method of
drawing up a table of chords. For example, the side of a hexagon
inscribed in a circle is equal to the radius, and is the chord of 60°,
or of the sixth part of the circle. The radius is divided into sixty
equal parts, and these again divided and subdivided sexagesimally. The
smaller divisions and the subdivisions are known as prime minute parts
and second minute parts (_partes minutæ primæ_ and _partes minutæ
secundæ_), whence our terms "minute" and "second." The sexagesimal
method of dividing the circle and its parts was, as we have seen in the
first chapter, of Babylonian origin.
Ptolemy was the last of the great Greek astronomers. In the fourth
century and at the beginning of the fifth, Theon and his illustrious
daughter Hypatia commented on and taught the astronomy of Ptolemy. In
the Greek schools of philosophy Plato's doctrine of the supreme reality
of the invisible world was harmonized for a time with Christian
mysticism, but these schools were suppressed at the beginning of the
sixth century. The extinction of scientific and of all other learning
seemed imminent.
What were the causes of this threatened break in the historical
continuity of science? They were too many and too varied to admit of
adequate statement here. From the latter part of the fourth century the
Roman Empire had been overrun by the Visigoths, the Vandals, the Huns,
the Ostrogoths, the Lombards, and other barbarians. Even before these
incursions learning had suffered under the calamity of war. In the time
of Julius Cæsar the larger of the famous libraries of Alexandria,
containing, it is computed, some 490,000 rolls, caught fire from ships
burning in the harbor, and perished. This alone involved an incalculable
setback to the march of scientific thought.
Another influence tending to check the advance of the sciences was the
clash between Christian and Pagan ideals. To many of the bishops of the
Church the aims and pursuits of science seemed vain and trivial when
compared with the preservation of purity of character or the assurance
of eternal felicity. Many were convinced that the end of the world was
at hand, and strove to fix their thoughts solely on the world to come.
Their austere disregard of this life found some support in a noble
teaching of the Stoic philosophy that death itself is no evil to the
just man. The early Christian teachers held that the body should be
mortified if it interfered with spiritual welfare. Disease is a
punishment, or a discipline to be patiently borne. One should choose
physical uncleanliness rather than run any risk of moral contamination.
It is not impossible for enlightened people at the present time
to assume a tolerant attitude toward the worldly Greeks or the
other-worldly Christians. At that time, however, mutual antipathy was
intense. The long and cruel war between science and Christian theology
had begun.
Not all the Christian bishops, to be sure, took a hostile view of Greek
learning. Some regarded the great philosophers as the allies of the
Church. Some held that churchmen should study the wisdom of the Greeks
in order the better to refute them. Others held that the investigation
of truth was no longer necessary after mankind had received the
revelation of the gospel. One of the ablest of the Church Fathers
regretted his early education and said that it would have been better
for him if he had never heard of Democritus. The Christian writer
Lactantius asked shrewdly whence atoms came, and what proof there was of
their existence. He also allowed himself to ridicule the idea of the
antipodes, a topsy-turvy world of unimaginable disorder. In 389 A.D. one
of the libraries at Alexandria was destroyed and its books were pillaged
by the Christians. In 415 Hypatia, Greek philosopher and mathematician,
was murdered by a Christian mob. In 642 the Arabs having pushed their
conquest into northern Africa gained possession of Alexandria. The cause
of learning seemed finally and irrecoverably lost.
The Arab conquerors, however, showed themselves singularly hospitable to
the culture of the nations over which they had gained control. Since the
time of Alexander there had been many Greek settlers in the larger
cities of Syria and Persia, and here learning had been maintained in the
schools of the Jews and of a sect of Christians (Nestorians), who were
particularly active as educators from the fifth century to the eleventh.
The principal Greek works on science had been translated into Syrian.
Hindu arithmetic and astronomy had found their way into Persia. By the
ninth century all these sources of scientific knowledge had been
appropriated by the Arabs. Some fanatics among them, to be sure, held
that one book, the Koran, was of itself sufficient to insure the
well-being of the whole human race, but happily a more enlightened view
prevailed.
In the time of Harun Al-Rashid (800 A.D.), and his son, the Caliphate
of Bagdad was the center of Arab science. Mathematics and astronomy were
especially cultivated; an observatory was established; and the work of
translation was systematically carried on by a sort of institute of
translators, who rendered the writings of Aristotle, Hippocrates, Galen,
Euclid, Ptolemy, and other Greek scientists, into Arabic. The names of
the great Arab astronomers and mathematicians are not popularly known to
us; their influence is greater than their fame. One of them describes
the method pursued by him in the ninth century in taking measure of the
circumference of the earth. A second developed a trigonometry of sines
to replace the Ptolemaic trigonometry of chords. A third made use of the
so-called Arabic (really Hindu) system of numerals, and wrote the first
work on Algebra under that name. In this the writer did not aim at the
mental discipline of students, but sought to confine himself to what is
easiest and most useful in calculation, "such as men constantly require
in cases of inheritance, legacies, partition, law-suits, and trade, and
in all their dealings with one another, or where the measuring of lands,
the digging of canals, geometrical computation, and other objects of
various sorts and kinds are concerned."
In the following centuries Arab institutions of higher learning were
widely distributed and the flood-tide of Arab science was borne farther
west. At Cairo about the close of the tenth century the first accurate
records of eclipses were made, and tables were constructed of the
motions of the sun, moon, and planets. Here as elsewhere the Arabs
displayed ingenuity in the making of scientific apparatus, celestial
globes, sextants of large size, quadrants of various sorts, and
contrivances from which in the course of time were developed modern
surveying instruments for measuring horizontal and vertical angles.
Before the end of the eleventh century an Arab born at Cordova, the
capital of Moorish Spain, constructed the Toletan Tables. These were
followed in 1252 by the publication of the Alphonsine Tables, an event
which astronomers regard as marking the dawn of European science.
Physics and chemistry, as well as mathematics and astronomy, owe much in
their development to the Arabs. An Arabian scientist of the eleventh
century studied the phenomena of the reflection and refraction of light,
explained the causes of morning and evening twilight, understood the
magnifying power of lenses and the anatomy of the human eye. Our use of
the terms retina, cornea, and vitreous humor may be traced to
the translation of his work on optics. The Arabs also made fair
approximations to the correct specific weights of gold, copper, mercury,
and lead. Their alchemy was closely associated with metallurgy, the
making of alloys and amalgams, and the handicrafts of the goldsmiths and
silversmiths. The alchemists sought to discover processes whereby one
metal might be transmuted into another. Sulphur affected the color and
substance. Mercury was supposed to play an important part in metal
transmutations. They thought, for example, that tin contained more
mercury than lead, and that the baser, more unhealthy metal might be
converted into the nobler and more healthy by the addition of mercury.
They even sought for a substance that might effect all transmutations,
and be for mankind a cure for all ailments, even that of growing old.
The writings that have been attributed to Geber show the advances that
chemistry made through the experiments of the Arabs. They produced
sulphuric and nitric acids, and _aqua regia_, able to dissolve gold, the
king of metals. They could make use of wet methods, and form metallic
salts such as silver nitrate. Laboratory processes like distilling,
filtering, crystallization, sublimation, became known to the Europeans
through them. They obtained potash from wine lees, soda from sea-plants,
and from quicksilver the mercuric oxide which played so interesting a
part in the later history of chemistry.
Much of the science lore of the Arabs arose from their extensive trade,
and in the practice of medicine. They introduced sugar-cane into Europe,
improved the methods of manufacturing paper, discovered a method of
obtaining alcohol, knew the uses of gypsum and of white arsenic, were
expert in pharmacy and learned in materia medica. They are sometimes
credited with introducing to the West the knowledge of the mariner's
compass and of gunpowder.
Avicenna (980-1037), the Arab physician, not only wrote a large work on
medicine (the _Canon_) based on the lore of Galen, which was used as a
text-book for centuries in the universities of Europe, but wrote
commentaries on all the works of Aristotle. For Averroës (1126-1198),
the Arab physician and philosopher, was reserved the title "The
Commentator," due to his devotion to the works of the Greek biologist
and philosopher. It was through the commentaries of Averroës that
Aristotelian science became known in Europe during the Middle Ages. In
his view Aristotle was the founder and perfecter of science; yet he
showed an independent knowledge of physics and chemistry, and wrote on
astronomy and medicine as well as philosophy. He set forth the facts in
reference to natural phenomena purely in the interests of the truth. He
could not conceive of anything being created from nothing. At the same
time he taught that God is the essence, the eternal cause, of progress.
It is in humanity that intellect most clearly reveals itself, but there
is a transcendent intellect beyond, union with which is the highest
bliss of the individual soul. With the death of the Commentator the
culture of liberal science among the Arabs came to an end, but his
influence (and through him that of Aristotle) was perpetuated in all the
western centers of education.
The preservation of the ancient learning had not, however, depended
solely on the Arabs. At the beginning of the sixth century, before the
taking of Alexandria by the followers of Mohammed, St. Benedict had
founded the monastery of Monte Cassino in Italy. Here was begun the
copying of manuscripts, and the preparation of compendiums treating of
grammar, dialectic, rhetoric, arithmetic, astronomy, music, and
geometry. These were based on ancient, Roman writings. Works like
Pliny's _Natural History_, the encyclopedia of the Middle Ages, had
survived all the wars by which Rome had been devastated. Learning, which
in Rome's darkest days had found refuge in Britain and Ireland, returned
book in hand. Charlemagne (800) called Alcuin from York to instruct
princes and nobles at the Frankish court. At this same palace school
half a century later the Irishman Scotus Erigena exhibited his learning,
wit, and logical acumen. In the tenth century Gerbert (Pope Sylvester
II) learned mathematics at Arab schools in Spain. The translation of
Arab works on science into the Latin language, freer intercourse of
European peoples with the East through war and trade, economic
prosperity, the liberation of serfs and the development of a well-to-do
middle class, the voyages of Marco Polo to the Orient, the founding of
universities, the encouragement of learning by the Emperor Frederick II,
the study of logic by the schoolmen, were all indicative of a new era in
the history of scientific thought.
The learned Dominican Albertus Magnus (1193-1280) was a careful student
of Aristotle as well as of his Arabian commentators. In his many books
on natural history he of course pays great deference to the Philosopher,
but he is not devoid of original observation. As the official visitor of
his order he had traveled through the greater part of Germany on foot,
and with a keen eye for natural phenomena was able to enrich botany and
zoölogy by much accurate information. His intimacy with the details of
natural history made him suspected by the ignorant of the practice of
magical arts.
His pupil and disciple Thomas Aquinas (1227-1274) was the philosopher
and recognized champion of the Christian Church. In 1879 Pope Leo XIII,
while proclaiming that every wise saying, every useful discovery, by
whomsoever it may be wrought, should be welcomed with a willing and
grateful mind, exhorted the leaders of the Roman Catholic Church to
restore the golden wisdom of St. Thomas and to propagate it as widely as
possible for the good of society and the advancement of all the
sciences. Certainly the genius of St. Thomas Aquinas seems comprehensive
enough to embrace all science as well as all philosophy from the
Christian point of view. According to him there are two sources of
knowledge, reason and revelation. These are not irreconcilably opposed.
The Greek philosophers speak with the voice of reason. It is the duty of
theology to bring all knowledge into harmony with the truths of
revelation imparted by God for the salvation of the human race. Averroës
is in error when he argues the impossibility of something being created
from nothing, and again when he implies that the individual intellect
becomes merged in a transcendental intellect; for such teaching would be
the contrary of what has been revealed in reference to the creation of
the world and the immortality of the individual soul. In the
accompanying illustration we see St. Thomas inspired by Christ in glory,
guided by Moses, St. Peter, and the Evangelists, and instructed by
Aristotle and Plato. He has overcome the heathen philosopher Averroës,
who lies below discomfited.
[Illustration: ST. THOMAS AQUINAS OVERCOMING AVERROËS]
The English Franciscan Roger Bacon (1214-1294) deserves to be mentioned
with the two great Dominicans. He was acquainted with the works of the
Greek and Arabian scientists. He transmitted in a treatise that fell
under the eye of Columbus the view of Aristotle in reference to the
proximity of another continent on the other side of the Atlantic; he
anticipated the principle on which the telescope was afterwards
constructed; he advocated basing natural science on experience and
careful observation rather than on a process of reasoning. Roger Bacon's
writings are characterized by a philosophical breadth of view. To his
mind the earth is only an insignificant dot in the center of the vast
heavens.
In the centuries that followed the death of Bacon the relation of this
planet to the heavenly bodies was made an object of study by a
succession of scientists who like him were versed in the achievements of
preceding ages. Peurbach (1423-1461), author of _New Theories of the
Planets_, developed the trigonometry of the Arabians, but died before
fulfilling his plan to give Europe an epitome of the astronomy of
Ptolemy. His pupil, Regiomontanus, however, more than made good the
intentions of his master. The work of Peurbach had as commentator the
first teacher in astronomy of Copernicus (1473-1543). Later Copernicus
spent nine years in Italy, studying at the universities and acquainting
himself with Ptolemaic and other ancient views concerning the motions of
the planets. He came to see that the apparent revolution of the heavenly
bodies about the earth from east to west is really owing to the
revolution of the earth on its axis from west to east. This view was so
contrary to prevailing beliefs that Copernicus refused to publish his
theory for thirty-six years. A copy of his book, teaching that our earth
is not the center of the universe, was brought to him on his deathbed,
but he never opened it.
Momentous as was this discovery, setting aside the geocentric system
which had held captive the best minds for fourteen slow centuries and
substituting the heliocentric, it was but a link in the chain of
successes in astronomy to which Tycho Brahe, Kepler, Galileo, Newton,
and their followers contributed.
REFERENCES
_The Catholic Encyclopedia._
J. L. E. Dreyer, _History of the Planetary Systems_.
_Encyclopædia Britannica._ Arabian Philosophy; Roger Bacon.
W. J. Townsend, _The Great Schoolmen of the Middle Ages_.
R. B. Vaughan, _St. Thomas of Aquin; his Life and Labours_.
Andrew D. White, _A History of the Warfare of Science with Theology in
Christendom_.
CHAPTER V
THE CLASSIFICATION OF THE SCIENCES--FRANCIS BACON
The preceding chapter has shown that there is a continuity in the
development of single sciences. The astronomy, or the chemistry, or the
mathematics, of one period depends so directly on the respective science
of the foregoing period, that one feels justified in using the term
"growth," or "evolution," to describe their progress. Now a vital
relationship can be observed not only among different stages of the same
science, but also among the different sciences. Physics, astronomy, and
chemistry have much in common; geometry, trigonometry, arithmetic, and
algebra are called "branches" of mathematics; zoölogy and botany are
biological sciences, as having to do with living species. In the century
following the death of Copernicus, two great scientists, Bacon and
Descartes, compared all knowledge to a tree, of which the separate
sciences are branches. They thought of all knowledge as a living
organism with an interconnection or continuity of parts, and a
capability of growth.
By the beginning of the seventeenth century the sciences were so
considerable that in the interest of further progress a comprehensive
view of the tree of knowledge, a survey of the field of learning, was
needed. The task of making this survey was undertaken by Francis Bacon,
Lord Verulam (1561-1626). His classification of human knowledge was
celebrated, and very influential in the progress of science. He kept one
clear purpose in view, namely, the control of nature by man. He wished
to take stock of what had already been accomplished, to supply
deficiencies, and to enlarge the bounds of human empire. He was acutely
conscious that this was an enterprise too great for any one man, and he
used his utmost endeavors to induce James I to become the patron of the
plan. His project admits of very simple statement now; he wished to edit
an encyclopedia, but feared that it might prove impossible without
coöperation and without state support. He felt capable of furnishing the
plans for the building, but thought it a hardship that he was compelled
to serve both as architect and laborer. The worthiness of these plans
was attested in the middle of the eighteenth century, when the great
French _Encyclopaedia_ was projected by Diderot and D'Alembert. The
former, its chief editor and contributor, wrote in the Prospectus: "If
we come out successful from this vast undertaking, we shall owe it
mainly to Chancellor Bacon, who sketched the plan of a universal
dictionary of sciences and arts at a time when there were not, so to
speak, either arts or sciences. This extraordinary genius, when it was
impossible to write a history of what men knew, wrote one of what they
had to learn."
Bacon, as we shall amply see, was a firm believer in the study
of the arts and occupations, and at the same time retained his
devotion to principles and abstract thought. He knew that philosophy
could aid the arts that supply daily needs; also that the arts and
occupations enriched the field of philosophy, and that the basis of our
generalizations must be the universe of things knowable. "For," he
writes, "if men judge that learning should be referred to use and
action, they judge well; but it is easy in this to fall into the error
pointed out in the ancient fable; in which the other parts of the body
found fault with the stomach, because it neither performed the office of
motion as the limbs do, nor of sense, as the head does; but yet
notwithstanding it is the stomach which digests and distributes the
aliment to all the rest. So that if any man think that philosophy and
universality are idle and unprofitable studies, he does not consider
that all arts and professions are from thence supplied with sap and
strength." For Bacon, as for Descartes, natural philosophy was the trunk
of the tree of knowledge.
Human Learning (Bacon's Classification)
Column Key:
(A) Reason Philosophy, or the Sciences
(B) Imagination Poesy
(C) Memory History
---------------------------------------------------------------------------
Philosophia prima, or sapience
-----+---+--------+----------------------+---------------------------------
(A) | | | Civil Philosophy | Intercourse
| N | | (Standards of | Business
| a | | right in:) | Government
| t | Man +---------------+------+---------------------------------
| u | | Philosophy | Body | Medicine, Athletics, etc.
| r | | of Humanity +------+---------------------------------
| a | | (Anthropology)| | Logic
| l | | | Soul |
| | | | | Ethics
| P +--------+-------------+-+------+--------+----------+-------------
| h | | | Physics | Concrete |
| i | | | (Material and | | M
| l | | | Secondary | Abstract | a
| o | | | Causes) | | t
| s | Nature | Speculative | | | h
| o | | | Metaphysics | Concrete | e
| p | | | (Form and Final | | m
| h | | | Causes) | Abstract | a
| y | +-------------+-----------------+----------+ t
| | | | Mechanics | i
| | | Operative | | c
| | | | Purified Magic | s
| +--------+-------------+----------------------------+-------------
| | God | Natural Theology, Nature of Angels and Spirits
+---+--------+--------------------------------------------------------
| Divinity | Revelation
-----+------------+--------------------------------------------------------
(B) | Narrative, or Heroical
| Dramatic
| Parabolic (Fables)
-----+-----------+------------------------+--------------------------------
(C) | | Political | Memorials
| Civil | (Civil History proper) | Antiquities
| | | Perfect History
| +-----------+------------+--------------------------------
| | | Learning
| | Literary |
| | | Arts
| +-----------+---------------------------------------------
| | Ecclesiastical
+-----------+-------------------+-------------------+-----------------
| | Bonds | Arts | Mechanical
| | (Control by Man) | | Experimental
| +-------------------+-------------------+-----------------
| | Errors | Pretergenerations
| Natural | (Anomics) | (Monsters)
| +-------------------+---------------+---------------------
| | Freedom | Generations | Astronomical Physics
| | (Nomic Law) | | Physical Geography
| | | | Physics of Matter
| | | | Organic Species
-----+-----------+-------------------+---------------+---------------------
------------+----------------------------------------------------
| Knowledge Classified (Hugo of St. Victor, d. 1141).
------------+---------------------+------------------------------
Theoretical | Theology |
| Natural Philosophy |
| (Physic) |
------------+---------------------+------------------------------
| Mathematics | Arithmetic
| | Music (study of harmony)
| | Geometry
| | Astronomy
------------+---------------------+------------------------------
Practical | Ethics, or individual morality
(Moral) | Economics, or family morality
| Politics, or civics
------------+----------------------------------------------------
Mechanical | Weaving, spinning, sewing; work in wool, flax, etc.
| Equipment--arms, ships; work in stone, wood, metal
| Navigation
| Agriculture
| Hunting, fishing, foods
| Medicine
| Theatricals--drama, music, athletics, etc.
------------+----------------------------------------------------
Logical | Oratory
| Grammar
| Dialectic
| Rhetoric
------------+----------------------------------------------------
On the other hand, he looked to the arts, crafts, and occupations as a
source of scientific principles. In his survey of learning he found some
records of agriculture and likewise of many mechanical arts. Some think
them a kind of dishonor. "But if my judgment be of any weight, the use
of History Mechanical is, of all others, the most radical and
fundamental towards natural philosophy." When the different arts are
known, the senses will furnish sufficient concrete material for the
information of the understanding. The record of the arts is of most use
because it exhibits things in motion, and leads more directly to
practice. "Upon this history, therefore, mechanical and illiberal as it
may seem (all fineness and daintiness set aside), the greatest diligence
must be bestowed." "Again, among the particular arts those are to be
preferred which exhibit, alter, and prepare natural bodies and
materials of things as agriculture, cooking, chemistry, dyeing; the
manufacture of glass, enamel, sugar, gunpowder, artificial fires, paper
and the like." Weaving, carpentry, architecture, manufacture of mills,
clocks, etc. follow. The purpose is not solely to bring the arts to
perfection, but all mechanical experiments should be as streams flowing
from all sides into the sea of philosophy.
Shortly after James I came to the throne in 1603, Bacon published his
_Advancement of Learning_. He continued in other writings, however, to
develop the organization of knowledge, and in 1623 summed up his plan in
the _De Augmentis Scientiarum_.
A recent writer (Pearson, 1900) has attempted to summarize Bacon's
classification of the different branches of learning. When one compares
this summary with an outline of the classification of knowledge made by
the French monk, Hugo of St. Victor, who stands midway between Isidore
of Seville (570-636) and Bacon, some points of resemblance are of course
obvious. Moreover, Hugo, like Bacon, insisted on the importance of not
being narrowly utilitarian. Men, he says, are often accustomed to value
knowledge not on its own account but for what it yields. Thus it is with
the arts of husbandry, weaving, painting, and the like, where skill is
considered absolutely vain, unless it results in some useful product.
If, however, we judged after this fashion of God's wisdom, then, no
doubt, the creation would be preferred to the Creator. But wisdom is
life, and the love of wisdom is the joy of life (_felicitas vitæ_).
Nevertheless, when we compare these classifications diligently, we find
very marked differences between Bacon's views and the medieval. The
weakest part of Hugo's classification is that which deals with natural
philosophy. _Physica_, he says, undertakes the investigation of the
causes of things in their effects, and of effects in their causes. It
deals with the explanation of earthquakes, tides, the virtues of plants,
the fierce instincts of wild animals, every species of stone, shrub, and
reptile. When we turn to his special work, however, on this branch of
knowledge, _Concerning Beasts and Other Things_, we find no attempt to
subdivide the field of _physica_, but a series of details in botany,
geology, zoölogy, and human anatomy, mostly arranged in dictionary form.
When we refer to Bacon's classification we find that Physics corresponds
to Hugo's _Physica_. It studies natural phenomena in relation to their
material causes. For this study, Natural History, according to Bacon,
supplies the facts. Let us glance, then, at his work on natural history,
and see how far he had advanced from the medieval toward the modern
conception of the sciences.
For purposes of scientific study he divided the phenomena of the
universe into (1) Celestial phenomena; (2) Atmosphere; (3) Globe; (4)
Substance of earth, air, fire, water; (5) Genera, species, etc. Great
scope is given to the natural history of man. The arts are classified as
_nature modified by man_. _History_ means, of course, descriptive
science.
_Bacon's Catalogue of Particular Histories by Titles (1620)_
1. History of the Heavenly Bodies; or Astronomical History.
2. History of the Configuration of the Heavens and the parts thereof
towards the Earth and the parts thereof; or Cosmographical
History.
3. History of Comets.
4. History of Fiery Meteors.
5. History of Lightnings, Thunderbolts, Thunders, and Coruscations.
6. History of Winds and Sudden Blasts and Undulations of the Air.
7. History of Rainbows.
8. History of Clouds, as they are seen above.
9. History of the Blue Expanse, of Twilight, of Mock-Suns,
Mock-Moons, Haloes, various colours of the Sun; and of every
variety in the aspect of the heavens caused by the medium.
10. History of Showers, Ordinary, Stormy, and Prodigious; also of
Waterspouts (as they are called); and the like.
11. History of Hail, Snow, Frost, Hoar-frost, Fog, Dew, and the like.
12. History of all other things that fall or descend from above, and
that are generated in the upper region.
13. History of Sounds in the upper region (if there be any), besides
Thunder.
14. History of Air as a whole, or in the Configuration of the World.
15. History of the Seasons or Temperatures of the Year, as well
according to the variations of Regions as according to accidents
of Times and Periods of Years; of Floods, Heats, Droughts, and the
like.
16. History of Earth and Sea; of the Shape and Compass of them, and
their Configurations compared with each other; and of their
broadening or narrowing; of Islands in the Sea; of Gulfs of the
Sea, and Salt Lakes within the Land; Isthmuses and Promontories.
17. History of the Motions (if any be) of the Globe of Earth and Sea;
and of the Experiments from which such motions may be collected.
18. History of the greater motions and Perturbations in Earth and Sea;
Earthquakes, Tremblings and Yawnings of the Earth, Islands newly
appearing; Floating Islands; Breakings off of Land by entrance of
the Sea, Encroachments and Inundations and contrariwise Recessions
of the Sea; Eruptions of Fire from the Earth; Sudden Eruptions of
Waters from the Earth; and the like.
19. Natural History of Geography; of Mountains, Vallies, Woods,
Plains, Sands, Marshes, Lakes, Rivers, Torrents, Springs, and
every variety of their course, and the like; leaving apart
Nations, Provinces, Cities, and such like matters pertaining to
Civil life.
20. History of Ebbs and Flows of the Sea; Currents, Undulations, and
other Motions of the Sea.
21. History of other Accidents of the Sea; its Saltness, its various
Colours, its Depth; also of Rocks, Mountains, and Vallies under
the Sea, and the like.
_Next come Histories of the Greater Masses_
22. History of Flame and of things Ignited.
23. History of Air, in Substance, not in the Configuration of the
World.
24. History of Water, in Substance, not in the Configuration of the
World.
25. History of the Earth and the diversity thereof, in Substance, not
in the Configuration of the World.
_Next come Histories of Species_
26. History of perfect Metals, Gold, Silver; and of the Mines, Veins,
Marcasites of the same; also of the Working in the Mines.
27. History of Quicksilver.
28. History of Fossils; as Vitriol, Sulphur, etc.
29. History of Gems; as the Diamond, the Ruby, etc.
30. History of Stones; as Marble, Touchstone, Flint, etc.
31. History of the Magnet.
32. History of Miscellaneous Bodies, which are neither entirely Fossil
nor Vegetable; as Salts, Amber, Ambergris, etc.
33. Chemical History of Metals and Minerals.
34. History of Plants, Trees, Shrubs, Herbs; and of their parts,
Roots, Stalks, Wood, Leaves, Flowers, Fruits, Seeds, Gums, etc.
35. Chemical History of Vegetables.
36. History of Fishes, and the Parts and Generation of them.
37. History of Birds, and the Parts and Generation of them.
38. History of Quadrupeds, and the Parts and Generation of them.
39. History of Serpents, Worms, Flies, and other insects; and of the
Parts and Generation of them.
40. Chemical History of the things which are taken by Animals.
_Next come Histories of Man_
41. History of the Figure and External Limbs of man, his Stature,
Frame, Countenance, and Features; and of the variety of the same
according to Races and Climates, or other smaller differences.
42. Physiognomical History of the same.
43. Anatomical History, or of the Internal Members of Man; and of the
variety of them, as it is found in the Natural Frame and
Structure, and not merely as regards Diseases and Accidents out of
the course of Nature.
44. History of the parts of Uniform Structure in Man; as Flesh, Bones,
Membranes, etc.
45. History of Humours in Man; Blood, Bile, Seed, etc.
46. History of Excrements; Spittle, Urine, Sweats, Stools, Hair of the
Head, Hairs of the Body, Whitlows, Nails, and the like.
47. History of Faculties; Attraction, Digestion, Retention,
Expulsion, Sanguification, Assimilation of Aliment into the
members, conversion of Blood and Flower of Blood into Spirit, etc.
48. History of Natural and Involuntary Motions; as Motion of the
Heart, the Pulses, Sneezing, Lungs, Erection, etc.
49. History of Motions partly Natural and Partly Violent; as of
Respiration, Cough, Urine, Stool, etc.
50. History of Voluntary Motions; as of the Instruments of
Articulation of Words; Motions of the Eyes, Tongue, Jaws, Hands,
Fingers; of Swallowing, etc.
51. History of Sleep and Dreams.
52. History of different habits of Body--Fat, Lean; of the Complexions
(as they call them), etc.
53. History of the Generation of Man.
54. History of Conception, Vivification, Gestation in the Womb, Birth,
etc.
55. History of the Food of Man; and of all things Eatable and
Drinkable; and of all Diet; and of the variety of the same
according to nations and smaller differences.
56. History of the Growth and Increase of the Body, in the whole and
in its parts.
57. History of the Course of Age; Infancy, Boyhood, Youth, Old Age; of
Length and Shortness of Life, and the like, according to nations
and lesser differences.
58. History of Life and Death.
59. History Medicinal of Diseases, and of the Symptoms and Signs of
them.
60. History Medicinal of the Treatment and Remedies and Cures of
Diseases.
61. History Medicinal of those things which preserve the Body and the
Health.
62. History Medicinal of those things which relate to the Form and
Comeliness of the Body.
63. History Medicinal of those things which alter the Body, and
pertain to Alterative Regimen.
64. History of Drugs.
65. History of Surgery.
66. Chemical History of Medicines.
67. History of Vision, and of things Visible.
68. History of Painting, Sculpture, Modelling, etc.
69. History of Hearing and Sound.
70. History of Music.
71. History of Smell and Smells.
72. History of Taste and Tastes.
73. History of Touch, and the objects of Touch.
74. History of Venus, as a species of Touch.
75. History of Bodily Pains, as species of Touch.
76. History of Pleasure and Pain in general.
77. History of the Affections; as Anger, Love, Shame, etc.
78. History of the Intellectual Faculties; Reflexion, Imagination,
Discourse, Memory, etc.
79. History of Natural Divinations.
80. History of Diagnostics, or Secret Natural Judgements.
81. History of Cookery, and of the arts thereto belonging, as of the
Butcher, Poulterer, etc.
82. History of Baking, and the Making of Bread, and the arts thereto
belonging, as of the Miller, etc.
83. History of Wine.
84. History of the Cellar and of different kinds of Drink.
85. History of Sweetmeats and Confections.
86. History of Honey.
87. History of Sugar.
88. History of the Dairy.
89. History of Baths and Ointments.
90. Miscellaneous History concerning the care of the body--as of
Barbers, Perfumers, etc.
91. History of the working of Gold, and the arts thereto belonging.
92. History of the manufactures of Wool, and the arts thereto
belonging.
93. History of the manufactures of Silk, and the arts thereto
belonging.
94. History of the manufactures of Flax, Hemp, Cotton, Hair, and
other kinds of Thread, and the arts thereto belonging.
95. History of manufactures of Feathers.
96. History of Weaving, and the arts thereto belonging.
97. History of Dyeing.
98. History of Leather-making, Tanning, and the arts thereto
belonging.
99. History of Ticking and Feathers.
100. History of working in Iron.
101. History of Stone-cutting.
102. History of the making of Bricks and Tiles.
103. History of Pottery.
104. History of Cements, etc.
105. History of working in Wood.
106. History of working in Lead.
107. History of Glass and all vitreous substances, and of Glass-making.
108. History of Architecture generally.
109. History of Waggons, Chariots, Litters, etc.
110. History of Printing, of Books, of Writing, of Sealing; of Ink,
Pen, Paper, Parchment, etc.
111. History of Wax.
112. History of Basket-making.
113. History of Mat-making, and of manufactures of Straw, Rushes, and
the like.
114. History of Washing, Scouring, etc.
115. History of Agriculture, Pasturage, Culture of Woods, etc.
116. History of Gardening.
117. History of Fishing.
118. History of Hunting and Fowling.
119. History of the Art of War, and of the arts thereto belonging, as
Armoury, Bow-making, Arrow-making, Musketry, Ordnance, Cross-bows,
Machines, etc.
120. History of the Art of Navigation, and of the crafts and arts
thereto belonging.
121. History of Athletics and Human Exercises of all kinds.
122. History of Horsemanship.
123. History of Games of all kinds.
124. History of Jugglers and Mountebanks.
125. Miscellaneous History of various Artificial Materials,--Enamel,
Porcelain, various cements, etc.
126. History of Salts.
127. Miscellaneous History of various Machines and Motions.
128. Miscellaneous History of Common Experiments which have not grown
into an Art.
_Histories must also be written of Pure Mathematics; though they are
rather observations than experiments_
129. History of the Natures and Powers of Numbers.
130. History of the Natures and Powers of Figures.
The fragment containing this catalogue (_Parasceve_--Day of Preparation)
was added to Bacon's work on method, _The New Logic_ (_Novum Organum_),
1620. Besides completing his survey and classification of the sciences
(_De Augmentis Scientiarum_), 1623, he published a few separate writings
on topics in the catalogue--_Winds_, _Life and Death_, _Tides_, etc. In
1627, a year after his death, appeared his much misunderstood work,
_Sylva Sylvarum_. He had found that the Latin word _sylva_ meant _stuff_
or _raw material_, as well as a _wood_, and called this final work
_Sylva Sylvarum_, which I would translate, "Jungle of Raw Material." He
himself referred to it as "an undigested heap of particulars"; yet he
was willing it should be published because "he preferred the good of men
to anything that might have relation to himself." In it, following his
catalogue, he fulfilled the promise made in 1620, of putting nature and
the arts to question. Some of the problems suggested for investigation
are: congealing of air, turning air into water, the secret nature of
flame, motion of gravity, production of cold, nourishing of young
creatures in the egg or womb, prolongation of life, the media of sound,
infectious diseases, accelerating and preventing putrefaction,
accelerating and staying growth, producing fruit without core or seed,
production of composts and helps for ground, flying in the air.
In the _New Atlantis_, a work of imagination, Bacon had represented as
already achieved for mankind some of the benefits he wished for:
artificial metals, various cements, excellent dyes, animals for
vivisection and medical experiment, instruments which generate heat
solely by motion, artificial precious stones, conveyance of sound for
great distances and in tortuous lines, new explosives. "We imitate,"
says the guide in the Utopian land, "also flights of birds; we have some
degree of flying in the air; we have ships and boats for going under
water." Bacon believed in honoring the great discoverers and inventors,
and advocated maintaining a calendar of inventions.
He was a fertile and stimulating thinker, and much of his great
influence arose from the comprehensiveness that led to his celebrated
classification of the sciences.
REFERENCES
Bacon's _Philosophical Works_, vol. IV, _Parasceve_, edited by R. L.
Ellis, J. Spedding, and D. D. Heath.
Karl Pearson, _Grammar of Science_.
J. A. Thomson, _Introduction to Science_.
CHAPTER VI
SCIENTIFIC METHOD--GILBERT, GALILEO, HARVEY, DESCARTES
The previous chapter has given some indication of the range of the
material which was demanding scientific investigation at the end of the
sixteenth and the beginning of the seventeenth century. The same period
witnessed a conscious development of the method, or methods, of
investigation. As we have seen, Bacon wrote in 1620 a considerable work,
_The New Logic_ (_Novum Organum_), so called to distinguish it from the
traditional deductive logic. It aimed to furnish the organ or
instrument, to indicate the correct mental procedure, to be employed in
the discovery of natural law. Some seventeen years later, the
illustrious Frenchman René Descartes (1596-1650) published his
_Discourse on the Method of rightly conducting the Reason and seeking
Truth in the Sciences_. Both of these philosophers illustrated by their
own investigations the efficiency of the methods which they advocated.
[Illustration: _Painting by A. Ackland Hunt_
DR. GILBERT SHOWING HIS ELECTRICAL EXPERIMENTS TO QUEEN ELIZABETH AND
HER COURT]
Before 1620, however, the experimental method had already yielded
brilliant results in the hands of other scientists. We pass over
Leonardo da Vinci and many others in Italy and elsewhere, whose names
should be mentioned if we were tracing this method to its origin. By
1600 William Gilbert (1540-1603), physician to Queen Elizabeth, before
whom, as a picture in his birthplace illustrates, he was called to
demonstrate his discoveries, had published his work on the Magnet, the
outcome of about eighteen years of critical research. He may be
considered the founder of electrical science. Galileo, who discovered
the fundamental principles of dynamics and thus laid the basis of modern
physical science, although he did not publish his most important work
till 1638, had even before the close of the sixteenth century prepared
the way for the announcement of his principles by years of strict
experiment. By the year 1616, William Harvey (1578-1657), physician at
the court of James I, and, later, of Charles I, had, as the first modern
experimental physiologist, gained important results through his study of
the circulation of the blood.
It is not without significance that both Gilbert and Harvey had spent
years in Italy, where, as we have implied, the experimental method of
scientific research was early developed. Harvey was at Padua (1598-1602)
within the time of Galileo's popular professoriate, and may well have
been inspired by the physicist to explain on dynamical principles the
flow of blood through arteries and veins. This conjecture is the more
probable, since Galileo, like Harvey and Gilbert, had been trained in
the study of medicine. Bacon in turn had in his youth learned something
of the experimental method on the Continent of Europe, and, later, was
well aware of the studies of Gilbert and Galileo, as well as of Harvey,
who was indeed his personal physician.
Although these facts seem to indicate that method may be transmitted in
a nation or a profession, or through personal association, there still
remains some doubt as to whether anything so intimate as the mental
procedure involved in invention and in the discovery of truth can be
successfully imparted by instruction. The individuality of the man of
genius engaged in investigation must remain a factor difficult to
analyze. Bacon, whose purpose was to hasten man's empire over nature
through increasing the number of inventions and discoveries, recognized
that the method he illustrated is not the sole method of scientific
investigation. In fact, he definitely states that the method set forth
in the _Novum Organum_ is not original, or perfect, or indispensable. He
was aware that his method tended to the ignoring of genius and to the
putting of intelligences on one level. He knew that, although it is
desirable for the investigator to free his mind from prepossessions, and
to avoid premature generalizations, interpretation is the true and
natural work of the mind when free from impediments, and that the
conjecture of the man of genius must at times anticipate the slow
process of painful induction. As we shall see in the nineteenth chapter,
the psychology of to-day does not know enough about the workings of the
mind to prescribe a fixed mental attitude for the investigator.
Nevertheless, Bacon was not wrong in pointing out the virtues of a
method which he and many others turned to good account. Let us first
glance, however, at the activities of those scientists who preceded
Bacon in the employment of the experimental method.
Gilbert relied, in his investigations, on oft-repeated and verifiable
experiments, as can be seen from his work _De Magnete_. He directs the
experimenter, for example, to take a piece of loadstone of convenient
size and turn it on a lathe to the form of a ball. It then may be
called a _terrella_, or earthkin. Place on it a piece of iron wire. The
ends of the wire move round its middle point and suddenly come to a
standstill. Mark with chalk the line along which the wire lies still and
sticks. Then move the wire to other spots on the _terrella_ and repeat
your procedure. The lines thus marked, if produced, will form meridians,
all coming together at the poles. Again, place the magnet in a wooden
vessel, and then set the vessel afloat in a tub or cistern of still
water. The north pole of the stone will seek approximately the direction
of the south pole of the earth, etc. It was on the basis of scores of
experiments of this sort, carried on from about 1582 till 1600, that
Gilbert felt justified in concluding that the terrestrial globe is a
magnet. This theory has since that time been abundantly confirmed by
navigators. The full title of his book is _Concerning the Magnet and
Magnetic Bodies, and concerning the Great Magnet the Earth: A New
Natural History (Physiologia) demonstrated by many Arguments and
Experiments_. It does not detract from the credit of Gilbert's result to
state that his initial purpose was not to discover the nature of
magnetism or electricity, but to determine the true substance of the
earth, the innermost constitution of the globe. He was fully conscious
of his own method and speaks with scorn of certain writers who, having
made no magnetical experiments, constructed ratiocinations on the basis
of mere opinions and old-womanishly dreamed the things that were not.
Galileo (1564-1642) even as a child displayed something of the
inventor's ingenuity, and when he was nineteen, shortly after the
beginning of Gilbert's experiments, his keen perception for the
phenomena of motion led to his making a discovery of great scientific
moment. He observed a lamp swinging by a long chain in the cathedral of
his native city of Pisa, and noticed that, no matter how much the range
of the oscillations might vary, their times were constant. He verified
his first impressions by counting his pulse, the only available
timepiece. Later he invented simple pendulum devices for timing the
pulse of patients, and even made some advances in applying his discovery
in the construction of pendulum clocks.
b
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In 1589 he was appointed professor of mathematics in the University of
Pisa, and within a year or two established through experiment the
foundations of the science of dynamics. As early as 1590 he put on
record, in a Latin treatise _Concerning Motion_ (_De Motu_), his dissent
from the theories of Aristotle in reference to moving bodies, confuting
the Philosopher both by reason and ocular demonstration. Aristotle had
held that two moving bodies of the same sort and in the same medium have
velocities in proportion to their weights. If a moving body, whose
weight is represented by _b_, be carried through the line _c--e_ which
is divided in the point _d_, if, also, the moving body is divided
according to the same proportion as line _c--e_ is in the point _d_, it
is manifest that in the time taken to carry the whole body through
_c--e_, the part will be moved through _c--d_. Galileo said that it is
as clear as daylight that this view is ridiculous, for who would
believe that when two lead spheres are dropped from a great height, the
one being a hundred times heavier than the other, if the larger took an
hour to reach the earth, the smaller would take a hundred hours? Or,
that if from a high tower two stones, one twice the weight of the other,
should be pushed out at the same moment, the larger would strike the
ground while the smaller was still midway? His biography tells that
Galileo in the presence of professors and students dropped bodies of
different weights from the height of the Leaning Tower of Pisa to
demonstrate the truth of his views. If allowance be made for the
friction of the air, all bodies fall from the same height in equal
times: the final velocities are proportional to the times; the spaces
passed through are proportional to the squares of the times. The
experimental basis of the last two statements was furnished by means of
an inclined plane, down a smooth groove in which a bronze ball was
allowed to pass, the time being ascertained by means of an improvised
water-clock.
Galileo's mature views on dynamics received expression in a work
published in 1638, _Mathematical Discourses and Demonstrations
concerning Two New Sciences relating to Mechanics and Local Movements_.
It treats of cohesion and resistance to fracture (strength of
materials), and uniform, accelerated, and projectile motion (dynamics).
The discussion is in conversation form. The opening sentence shows
Galileo's tendency to base theory on the empirical. It might be freely
translated thus: "Large scope for intellectual speculation, I should
think, would be afforded, gentlemen, by frequent visits to your famous
Venetian Dockyard (_arsenale_), especially that part where mechanics are
in demand; seeing that there every sort of instrument and machine is put
to use by numbers of workmen, among whom, taught both by tradition and
their own observation, there must be some very skillful and also able to
talk." The view of the shipbuilders, that a large galley before being
set afloat is in greater danger of breaking under its own weight than a
small galley, is the starting-point of this most important of Galileo's
contributions to science.
Vesalius (1514-1564) had in his work on the structure of the human body
(_De Humani Corporis Fabrica_, 1543) shaken the authority of Galen's
anatomy; it remained for Harvey on the basis of the new anatomy to
improve upon the Greek physician's experimental physiology. Harvey
professed to learn and teach anatomy, not from books, but from
dissections, not from the dogmas of the philosophers, but from the
fabric of nature.
There have come down to us notes of his lectures on anatomy delivered
first in 1616. A brief extract will show that even at that date he had
already formulated a theory of the circulation of the blood:--
"[Illustration: WH monogram][1] By the structure of the heart it appears
that the blood is continually transfused through the lungs to the
aorta--as by the two clacks of a water-ram for raising water.
"It is shown by ligature that there is continuous motion of the blood
from arteries to veins.
"Whence Δ it is demonstrated that there is a continuous motion of the
blood in a circle, affected by the beat of the heart."
It was not till 1628 that Harvey published his _Anatomical Disquisition
on the Motion of the Heart and Blood in Animals_. It gives the
experimental basis of his conclusions. If a live snake be laid open, the
heart will be seen pulsating and propelling its contents. Compress the
large vein entering the heart, and the part intervening between the
point of constriction and the heart becomes empty and the organ pales
and shrinks. Remove the pressure, and the size and color of the heart
are restored. Now compress the artery leading from the organ, and the
part between the heart and the point of pressure, and the heart itself,
become distended and take on a deep purple color. The course of the
blood is evidently from the vena cava through the heart to the aorta.
Harvey in his investigations made use of many species of animals--at
least eighty-seven.
It was believed by some, before Harvey's demonstrations, that the
arteries were hollow pipes carrying air from the lungs throughout the
body, although Galen had shown by cutting a dog's trachea, inflating the
lungs and tying the trachea, that the lungs were in an enclosing sack
which retained the air. Harvey, following Galen, held that the pulmonary
artery, carrying blood to the lungs from the right side of the heart,
and the pulmonary veins, carrying blood from the lungs to the left side
of the heart, intercommunicate in the hidden porosities of the lungs and
through minute inosculations.
In man the vena cava carries the blood to the right side of the heart,
the pulmonary artery inosculates with the pulmonary veins, which convey
it to the left side of the heart. This muscular pump drives it into the
aorta. It still remains to be shown that in the limbs the blood passes
from the arteries to the veins. Bandage the arm so tightly that no pulse
is felt at the wrist. The hand appears at first natural, and then grows
cold. Loose the bandage sufficiently to restore the pulse. The hand and
forearm become suffused and swollen. In the first place the supply of
blood from the deep-lying arteries is cut off. In the second case the
blood returning by the superficial veins is dammed back. In the limbs as
in the lungs the blood passes from artery to vein by anastomoses and
porosities. All these arteries have their source in the aorta; all these
veins pour their stream ultimately into the vena cava. The veins have
valves, which prevent the blood flowing except toward the heart. Again,
the veins and arteries form a connected system; for through either a
vein or an artery all the blood may be drained off. The arguments by
which Harvey supported his view were various. The opening clause of his
first chapter, "When I first gave my mind to vivisection as a means of
discovering the motions and uses of the heart," throws a strong light on
his special method of experimental investigation.
Bacon, stimulated by what he called _philanthropia_, always aimed, as we
have seen, to establish man's control over nature. But all power of a
high order depends on an understanding of the essential character, or
law, of heat, light, sound, gravity, and the like. Nothing short of a
knowledge of the underlying nature of phenomena can give science
advantage over chance in hitting upon useful discoveries and inventions.
It is, therefore, natural to find him applying his method of
induction--his special method of true induction--to the investigation of
heat.
In the first place, let there be mustered, without premature
speculation, all the instances in which heat is manifested--flame,
lightning, sun's rays, quicklime sprinkled with water, damp hay, animal
heat, hot liquids, bodies subjected to friction. Add to these, instances
in which heat seems to be absent, as moon's rays, sun's rays on
mountains, oblique rays in the polar circle. Try the experiment of
concentrating on a thermoscope, by means of a burning-glass, the moon's
rays. Try with the burning-glass to concentrate heat from hot iron, from
common flame, from boiling water. Try a concave glass with the sun's
rays to see whether a diminution of heat results. Then make record of
other instances, in which heat is found in varying degrees. For example,
an anvil grows hot under the hammer. A thin plate of metal under
continuous blows might grow red like ignited iron. Let this be tried as
an experiment.
After the presentation of these instances induction itself must be set
to work to find out what factor is ever present in the positive
instances, what factor is ever wanting in the negative instances, what
factor always varies in the instances which show variation. According to
Bacon it is in the process of exclusion that the foundations of true
induction are laid. We can be certain, for example, that the essential
nature of heat does not consist in light and brightness, since it is
present in boiling water and absent in the moon's rays.
The induction, however, is not complete till something positive is
established. At this point in the investigation it is permissible to
venture an hypothesis in reference to the essential character of heat.
From a survey of the instances, all and each, it appears that the nature
of which heat is a particular case is motion. This is suggested by
flame, simmering liquids, the excitement of heat by motion, the
extinction of fire by compression, etc. Motion is the genus of which
heat is the species. Heat itself, its essence, is motion and nothing
else.
It remains to establish its specific differences. This accomplished, we
arrive at the definition: Heat is a motion, expansive, restrained, and
acting in its strife upon the smaller particles of bodies. Bacon,
glancing toward the application of this discovery, adds: "_If in any
natural body you can excite a dilating or expanding motion, and can so
repress this motion and turn it back upon itself, that the dilation
shall not proceed equally, but have its way in one part and be
counteracted in another, you will undoubtedly generate heat._" The
reader will recall that Bacon looked for the invention of instruments
that would generate heat solely by motion.
Descartes was a philosopher and mathematician. In his _Discourse on
Method_ and his _Rules for the Direction of the Mind_ (1628) he laid
emphasis on deduction rather than on induction. In the subordination of
particulars to general principles he experienced a satisfaction akin to
the sense of beauty or the joy of artistic production. He speaks
enthusiastically of that pleasure which one feels in truth, and which
in this world is about the only pure and unmixed happiness.
At the same time he shared Bacon's distrust of the Aristotelian logic
and maintained that ordinary dialectic is valueless for those who desire
to investigate the truth of things. There is need of a method for
finding out the truth. He compares himself to a smith forced to begin at
the beginning by fashioning tools with which to work.
In his method of discovery he determined to accept nothing as true that
he did not clearly recognize to be so. He stood against assumptions, and
insisted on rigid proof. Trust only what is completely known. Attain a
certitude equal to that of arithmetic and geometry. This attitude of
strict criticism is characteristic of the scientific mind.
Again, Descartes was bent on analyzing each difficulty in order to solve
it; to neglect no intermediate steps in the deduction, but to make the
enumeration of details adequate and methodical. Preserve a certain
order; do not attempt to jump from the ground to the gable, but rise
gradually from what is simple and easily understood.
Descartes' interest was not in the several branches of mathematics;
rather he wished to establish a universal mathematics, a general science
relating to order and measurement. He considered all physical nature,
including the human body, as a mechanism, capable of explanation on
mathematical principles. But his immediate interest lay in numerical
relationships and geometrical proportions.
Recognizing that the understanding was dependent on the other powers of
the mind, Descartes resorted in his mathematical demonstrations to the
use of lines, because he could find no method, as he says, more simple
or more capable of appealing to the imagination and senses. He
considered, however, that in order to bear the relationships in memory
or to embrace several at once, it was essential to explain them by
certain formulæ, the shorter the better. And for this purpose it was
requisite to borrow all that was best in geometrical analysis and
algebra, and to correct the errors of one by the other.
Descartes was above all a mathematician, and as such he may be regarded
as a forerunner of Newton and other scientists; at the same time he
developed an exact scientific method, which he believed applicable to
all departments of human thought. "Those long chains of reasoning," he
says, "quite simple and easy, which geometers are wont to employ in the
accomplishment of their most difficult demonstrations, led me to think
that everything which might fall under the cognizance of the human mind
might be connected together in the same manner, and that, provided only
one should take care not to receive anything as true which was not so,
and if one were always careful to preserve the order necessary for
deducing one truth from another, there would be none so remote at which
he might not at last arrive, or so concealed which he might not
discover."
REFERENCES
Francis Bacon, _Philosophical Works_ (Ellis and Spedding edition), vol.
IV, Novum Organum.
J. J. Fahie, _Galileo; His Life and Work_.
Galileo, _Two New Sciences_; translated by Henry Crew and Alphonse De
Salvio.
William Gilbert, _On the Loadstone_; translated by P. F. Mottelay.
William Harvey, _An Anatomical Disquisition on the Motion of the Heart
and Blood in Animals_.
T. H. Huxley, _Method and Results_.
D'Arcy Power, _William Harvey_ (in _Masters of Medicine_).
FOOTNOTES:
[1] This is Harvey's monogram, which he used in his notes to mark any
original observation.
CHAPTER VII
SCIENCE AS MEASUREMENT--TYCHO BRAHE, KEPLER, BOYLE
Considering the value for clearness of thought of counting, measuring
and weighing, it is not surprising to find that in the seventeenth
century, and even at the end of the sixteenth, the advance of the
sciences was accompanied by increased exactness of measurement and by
the invention of instruments of precision. The improvement of the simple
microscope, the invention of the compound microscope, of the telescope,
the micrometer, the barometer, the thermoscope, the thermometer, the
pendulum clock, the improvement of the mural quadrant, sextant, spheres,
astrolabes, belong to this period.
Measuring is a sort of counting, and weighing a form of measuring. We
may count disparate things whether like or unlike. When we measure or
weigh we apply a standard and count the times that the unit--cubit,
pound, hour--is found to repeat itself. We apply our measure to uniform
extension, meting out the waters by fathoms or space by the sun's
diameter, and even subject time to arbitrary divisions. The human mind
has been developed through contact with the multiplicity of physical
objects, and we find it impossible to think clearly and scientifically
about our environment without dividing, weighing, measuring, counting.
In measuring time we cannot rely on our inward impressions; we even
criticize these impressions and speak of time as going slowly or
quickly. We are compelled in the interests of accuracy to provide an
objective standard in the clock, or the revolving earth, or some other
measurable thing. Similarly with weight and heat; we cannot rely on the
subjective impression, but must devise apparatus to record by a
measurable movement the amount of the pressure or the degree of
temperature.
"God ordered all things by measure, number, and weight." The scientific
mind does not rest satisfied till it is able to see phenomena in their
number relationships. Scientific thought is in this sense Pythagorean,
that it inquires in reference to quantity and proportion.
As implied in a previous chapter, number relations are not clearly
grasped by primitive races. Many primitive languages have no words for
numerals higher than five. That fact does not imply that these races do
not know the difference between large and small numbers, but precision
grows with civilization, with commercial pursuits, and other activities,
such as the practice of medicine, to which the use of weights and
measures is essential. Scientific accuracy is dependent on words and
other means of numerical expression. From the use of fingers and toes, a
rude score or tally, knots on a string, or a simple abacus, the race
advances to greater refinement of numerical expression and the
employment of more and more accurate apparatus.
One of the greatest contributors to this advance was the celebrated
Danish astronomer, Tycho Brahe (1546-1601). Before 1597 he had completed
his great mural quadrant at the observatory of Uraniborg. He called it
with characteristic vanity the Tichonic quadrant. It consisted of a
graduated arc of solid polished brass five inches broad, two inches
thick, and with a radius of about six and three quarters feet. Each
degree was divided into minutes, and each minute into six parts. Each of
these parts was then subdivided into ten seconds, which were indicated
by dots arranged in transverse oblique lines on the width of brass.
[Illustration: THE TICHONIC QUADRANT]
The arc was attached in the observation room to a wall running exactly
north, and so secured with screws (_firmissimis cochleis_) that no force
could move it. With its concavity toward the southern sky it was closely
comparable, though reverse, to the celestial meridian throughout its
length from horizon to zenith. The south wall, above the point where the
radii of the quadrant met, was pierced by a cylinder of gilded brass
placed in a rectangular opening, which could be opened or closed from
the outside. The observation was made through one of two sights that
were attached to the graduated arc and could be moved from point to
point on it. In the sights were parallel slits, right, left, upper,
lower. If the altitude and the transit through the meridian were to be
taken at the same time the four directions were to be followed. It was
the practice for the student making the observation to read off the
number of degrees, minutes, etc., of the angle at which the altitude or
transit was observed, so that it might be recorded by a second student.
A third took the time from two clock dials when the observer gave the
signal, and the exact moment of observation was also recorded by
student number two. The clocks recorded minutes and the smaller
divisions of time; great care, however, was required to obtain good
results from them. There were four clocks in the observatory, of which
the largest had three wheels, one wheel of pure solid brass having
twelve hundred teeth and a diameter of two cubits.
Lest any space on the wall should lie empty a number of paintings were
added: Tycho himself in an easy attitude seated at a table and directing
from a book the work of his students. Over his head is an automatic
celestial globe invented by Tycho and constructed at his own expense in
1590. Over the globe is a part of Tycho's library. On either side are
represented as hanging small pictures of Tycho's patron, Frederick II of
Denmark (d. 1588) and Queen Sophia. Then other instruments and rooms of
the observatory are pictured; Tycho's students, of whom there were
always at least six or eight, not to mention younger pupils. There
appears also his great brass globe six feet in diameter. Then there is
pictured Tycho's chemical laboratory, on which he has expended much
money. Finally comes one of Tycho's hunting dogs--very faithful and
sagacious; he serves here as a hieroglyph of his master's nobility as
well as of sagacity and fidelity. The expert architect and the two
artists who assisted Tycho are delineated in the landscape and even in
the setting sun in the top-most part of the painting, and in the
decoration above.
The principal use of this largest quadrant was the determination of the
angle of elevation of the stars within the sixth part of a minute, the
collineation being made by means of one of the sights, the parallel
horizontal slits in which were aligned with the corresponding parts of
the circumference of the cylinder. The altitude was recorded according
to the position of the sight attached to the graduated arc.
Tycho Brahe had a great reverence for Copernicus, but he did not accept
his planetary system; and he felt that advance in astronomy depended on
painstaking observation. For over twenty years under the kings of
Denmark he had good opportunities for pursuing his investigation. The
island of Hven became his property. A thoroughly equipped observatory
was provided, including printing-press and workshops for the
construction of apparatus. As already implied, capable assistants were
at the astronomer's command. In 1598, after having left Denmark, Tycho
in a splendid illustrated book (_Astronomiæ Instauratæ Mechanica_) gave
an account of this astronomical paradise on the Insula Venusia as he at
times called it. The book, prepared for the hands of princes, contains
about twenty full-page colored illustrations of astronomical instruments
(including, of course, the mural quadrant), of the exterior of the
observatory of Uraniborg, etc. The author had a consciousness of his own
worth, and deserves the name Tycho the Magnificent. The results that
he obtained were not unworthy of the apparatus employed in his
observations, and before he died at Prague in 1601, Tycho Brahe had
consigned to the worthiest hands the painstaking record of his labors.
Johann Kepler (1571-1630) had been called, as the astronomer's
assistant, to the Bohemian capital in 1600 and in a few months fell heir
to Tycho's data in reference to 777 stars, which he made the basis of
the Rudolphine tables of 1627. Kepler's genius was complementary to that
of his predecessor. He was gifted with an imagination to turn
observations to account. His astronomy did not rest in mere description,
but sought the physical explanation. He had the artist's feeling for the
beauty and harmony, which he divined before he demonstrated, in the
number relations of the planetary movements. After special studies of
Mars based on Tycho's data, he set forth in 1609 (_Astronomia Nova_) (1)
that every planet moves in an ellipse of which the sun occupies one
focus, and (2) that the area swept by the radius vector from the planet
to the sun is proportional to the time. Luckily for the success of his
investigation the planet on which he had concentrated his attention is
the one of all the planets then known, the orbit of which most widely
differs from a circle. In a later work (_Harmonica Mundi_, 1619) the
title of which, the _Harmonics of the Universe_, proclaimed his
inclination to Pythagorean views, he demonstrated (3) that the square of
the periodic time of any planet is proportional to the cube of its mean
distance from the sun.
Kepler's studies were facilitated by the invention, in 1614 by John
Napier, of logarithms, which have been said, by abridging tedious
calculations, to double the life of an astronomer. About the same time
Kepler in purchasing some wine was struck by the rough-and-ready method
used by the merchant to determine the capacity of the wine-vessels. He
applied himself for a few days to the problems of mensuration involved,
and in 1615 published his treatise (_Stereometria Doliorum_) on the
cubical contents of casks (or wine-jars), a source of inspiration to all
later writers on the accurate determination of the volume of solids. He
helped other scientists and was himself richly helped. As early as 1610
there had been presented to him a means of precision of the first
importance to the progress of astronomy, namely, a Galilean telescope.
The early history of telescopes shows that the effect of combining two
lenses was understood by scientists long before any particular use was
made of this knowledge; and that those who are accredited with
introducing perspective glasses to the public hit by accident upon the
invention. Priority was claimed by two firms of spectacle-makers in
Middelburg, Holland, namely, Zacharias, miscalled Jansen, and
Lippershey. Galileo heard of the contrivance in July, 1609, and soon
furnished so powerful an instrument of discovery that things seen
through it appeared more than thirty times nearer and almost a thousand
times larger than when seen by the naked eye. He was able to make out
the mountains in the moon, the satellites of Jupiter in rotation, the
spots on the revolving sun; but his telescope afforded only an imperfect
view of Saturn. Of course these facts, published in 1610 (_Sidereus
Nuncius_), strengthened his advocacy of the Copernican system. Galileo
laughingly wrote Kepler that the professors of philosophy were afraid to
look through his telescope lest they should fall into heresy. The German
astronomer, who had years before written on the optics of astronomy,
now (1611) produced his _Dioptrice_, the first satisfactory statement of
the theory of the telescope.
About 1639 Gascoigne, a young Englishman, invented the micrometer, which
enables an observer to adjust a telescope with very great precision.
Before the invention of the micrometer exactitude was impossible,
because the adjustment of the instrument depended on the discrimination
of the naked eye. The micrometer was a further advance in exact
measurement. Gascoigne's determinations of, for example, the diameter of
the sun, bear comparison with the findings of even recent astronomical
science.
The history of the microscope is closely connected with that of the
telescope. In the first half of the seventeenth century the simple
microscope came into use. It was developed from the convex lens, which,
as we have seen in a previous chapter, had been known for centuries, if
not from remote antiquity. With the simple microscope Leeuwenhoek before
1673 had studied the structure of minute animal organisms and ten years
later had even obtained sight of bacteria. Very early in the same
century Zacharias had presented Prince Maurice, the commander of the
Dutch forces, and the Archduke Albert, governor of Holland, with
compound microscopes. Kircher (1601-1680) made use of an instrument that
represented microscopic forms as one thousand times larger than their
actual size, and by means of the compound microscope Malpighi was able
in 1661 to see blood flowing from the minute arteries to the minute
veins on the lung and on the distended bladder of the live frog. The
Italian microscopist thus, among his many achievements, verified by
observation what Harvey in 1628 had argued must take place.
In this same epoch apparatus of precision developed in other fields.
Weight clocks had been in use as time-measurers since the thirteenth
century, but they were, as we have seen, difficult to control and
otherwise unreliable. Even in the seventeenth century scientists in
their experiments preferred some form of water-clock. In 1636 Galileo,
in a letter, mentioned the feasibility of constructing a pendulum clock,
and in 1641 he dictated a description of the projected apparatus to his
son Vincenzo and to his disciple Viviani. He himself was then blind, and
he died the following year. His instructions were never carried into
effect. However, in 1657 Christian Huygens applied the pendulum to
weight clocks of the old stamp. In 1674 he gave directions for the
manufacture of a watch, the movement of which was driven by a spring.
Galileo, to whom the advance in exact science is so largely indebted,
must also be credited with the first apparatus for the measurement of
temperatures. This was invented before 1603 and consisted of a glass
bulb with a long stem of the thickness of a straw. The bulb was first
heated and the stem placed in water. The point at which the water, which
rose in the tube, might stand was an indication of the temperature. In
1631 Jean Rey just inverted this contrivance, filling the bulb with
water. Of course these thermoscopes would register the effect of varying
pressures as well as temperatures, and they soon made way for the
thermometer and the barometer. Before 1641 a true thermometer was
constructed by sealing the top of the tube after driving out the air by
heat. Spirits of wine were used in place of water. Mercury was not
employed till 1670.
Descartes and Galileo had brought under criticism the ancient idea that
nature abhors a vacuum. They knew that the _horror vacui_ was not
sufficient to raise water in a pump more than about thirty-three feet.
They had also known that air has weight, a fact which soon served to
explain the so-called force of suction. Galileo's associate Torricelli
reasoned that if the pressure of the air was sufficient to support a
column of water thirty-three feet in height, it would support a column
of mercury of equal weight. Accordingly in 1643 he made the experiment
of filling with mercury a glass tube four feet long closed at the upper
end, and then opening the lower end in a basin of mercury. The mercury
in the tube sank until its level was about thirty inches above that of
the mercury in the basin, leaving a vacuum in the upper part of the
tube. As the specific gravity of mercury is 13, Torricelli knew that his
supposition had been correct and that the column of mercury in the tube
and the column of water in the pump were owing to the pressure or weight
of the air.
Pascal thought that this pressure would be less at a high altitude. His
supposition was tested on a church steeple at Paris, and, later, on the
Puy de Dôme, a mountain in Auvergne. In the latter case a difference of
three inches in the column of mercury was shown at the summit and base
of the ascent. Later Pascal experimented with the siphon and succeeded
in explaining it on the principle of atmospheric pressure.
Torricelli in the space at the top of his barometer (pressure-gauge) had
produced what is called a Torricellian vacuum. Otto von Guericke, a
burgomaster of Magdeburg, who had traveled in France and Italy,
succeeded in constructing an air-pump by means of which air might be
exhausted from a vessel. Some of his results became widely known in
1657, though his works were not published till 1673.
Robert Boyle (1626-1691), born at Castle Lismore in Ireland, was the
seventh son and fourteenth child of the distinguished first Earl of
Cork. He was early acquainted with these various experiments in
reference to the air, as well as with Descartes' theory that air
is nothing but a congeries or heap of small, and, for the most
part, flexible particles. In 1659 he wrote his _New Experiments
Physico-Mechanical touching the Spring of the Air_. Instead of _spring_,
he at times used the word _elater_ (ἐλατὴρ). In this treatise he
describes experiments with the improved air-pump constructed at his
suggestion by his assistant, Robert Hooke.
One of Boyle's critics, a professor at Louvain, while admitting that air
had weight and elasticity, denied that these were sufficient to account
for the results ascribed to them. Boyle thereupon published a _Defence
of the Doctrine touching the Spring and Weight of the Air_. He felt able
to prove that the elasticity of the air could under circumstances do far
more than sustain twenty-nine or thirty inches of mercury. In support of
his view he cited a recent experiment.
He had taken a piece of strong glass tubing fully twelve feet in length.
(The experiment was made by a well-lighted staircase, the tube being
suspended by strings.) The glass was heated more than a foot from the
lower end, and bent so that the shorter leg of twelve inches was
parallel with the longer. The former was hermetically sealed at the top
and marked off in forty-eight quarter-inch spaces. Into the opening of
the longer leg, also graduated, mercury was poured. At first only enough
was introduced to fill the arch, or bent part of the tube below the
graduated legs. The tube was then inclined so that the air might pass
from one leg to the other, and equality of pressure at the start be
assured. Then more mercury was introduced and every time that the air in
the shorter leg was compressed a half or a quarter of an inch, a record
was made of the height of the mercury in the long leg of the tube. Boyle
reasoned that the compressed air was sustaining the pressure of the
column of mercury in the long leg _plus_ the pressure of the atmosphere
at the tube's opening, equivalent to 29-2/16 inches of mercury. Some of
the results were as follows: When the air in the short tube was
compressed from 12 to 3 inches, it was under a pressure of 117-9/16
inches of mercury; when compressed to 4 it was under pressure of
87-15/16 inches of mercury; when compressed to 6, 58-13/16; to 9,
39-5/8. Of course, when at the beginning of the experiment there were 12
inches of air in the short tube, it was under the pressure of the
atmosphere, equal to that of 29-2/16 inches of mercury. Boyle with
characteristic caution was not inclined to draw too general a conclusion
from his experiment. However, it was evident, making allowance for some
slight irregularity in the experimental results, that air reduced under
pressure to one half its original volume, doubles its resistance; and
that if it is further reduced to one half,--for example, from six to
three inches,--it has four times the resistance of common air. In fact,
Boyle had sustained the hypothesis that supposes the pressures and
expansions to be in reciprocal proportions.
REFERENCES
Sir Robert S. Ball, _Great Astronomers_.
Robert Boyle, _Works_ (edited by Thomas Birch).
Sir David Brewster, _Martyrs of Science_.
J. L. E. Dreyer, _Tycho Brahe_.
Sir Oliver Lodge, _Pioneers of Science_.
Flora Masson, _Robert Boyle; a Biography_.
CHAPTER VIII
COÖPERATION IN SCIENCE--THE ROYAL SOCIETY
The period from 1637 to 1687 affords a good illustration of the value
for the progress of science of the coöperation in the pursuit of truth
of men of different creeds, nationalities, vocations, and social ranks.
At, or even before, the beginning of that period the need of coöperation
was indicated by the activities of two men of pronouncedly social
temperament and interests, namely, the French Minim father, Mersenne,
and the Protestant Prussian merchant, Samuel Hartlib.
Mersenne was a stimulating and indefatigable correspondent. His letters
to Galileo, Jean Rey, Hobbes, Descartes, Gassendi, not to mention other
scientists and philosophers, constitute an encyclopedia of the learning
of the time. A mathematician and experimenter himself, he had a genius
for eliciting discussion and research by means of adroit questions.
Through him Descartes was drawn into debate with Hobbes, and with
Gassendi, a champion of the experimental method. Through him the
discoveries of Harvey, Galileo, and Torricelli, as well as of many
others, became widely known. His letters, in the dearth of scientific
associations and the absence of scientific periodicals, served as a
general news agency among the learned of his time. It is not surprising
that a coterie gathered about him at Paris. Hobbes spent months in
daily intercourse with this group of scientists in the winter of
1636-37.
Hartlib, though he scarcely takes rank with Mersenne as a scientist, was
no less influential. Of a generous and philanthropic disposition, he
repeatedly impoverished himself in the cause of human betterment. His
chief reliance was on education and improved methods of husbandry, but
he resembled Horace Greeley in his hospitality to any project for the
public welfare.
One of Hartlib's chief hopes for the regeneration of England, if not of
the whole world, rested on the teachings of the educational reformer
Comenius, a bishop of the Moravian Brethren. In 1637, Comenius having
shown himself rather reluctant to put his most cherished plans before
the public, his zealous disciple precipitated matters, and on his own
responsibility, and unknown to Comenius, issued from his library at
Oxford _Preludes to the Endeavors of Comenius_. Besides Hartlib's
preface it contained a treatise by the great educator on a _Seminary of
Christian Pansophy_, a method of imparting an encyclopedic knowledge of
the sciences and arts.
The two friends were followers of the Baconian philosophy. They were
influenced, as many others of the time, by the _New Atlantis_, which
went through ten editions between 1627 and 1670, and which outlined a
plan for an endowed college with thirty-six Fellows divided into
groups--what would be called to-day a university of research endowed by
the State. It is not surprising to find Comenius (who in his student
days had been under the influence of Alsted, author of an encyclopedia
on Baconian lines) speaking in 1638 on the need of a collegiate society
for carrying on the educational work that he himself had at heart.
In 1641 Hartlib published a work of fiction in the manner of the _New
Atlantis_, and dedicated it to the Long Parliament. In the same year he
urged Comenius to come to London, and published another work, _A
Reformation of Schools_. He had great influence and did not hesitate to
use it in his adoptive country. Everybody knew Hartlib, and he was
acquainted with all the strata of English society; for although his
father had been a merchant, first in Poland and later in Elbing, his
mother was the daughter of the Deputy of the English Company in Dantzic
and had relatives of rank in London, where Hartlib spent most of his
life. He gained the good-will of the Puritan Government, and even after
Cromwell's death was working, in conjunction with Boyle, for the
establishment of a national council of universal learning with Wilkins
as president.
When Comenius arrived in London he learned that the invitation had been
sent by order of Parliament. This body was very anxious to take up the
question of education, especially university education. Bacon's
criticisms of Oxford and Cambridge were still borne in mind; the
legislators considered that the college curriculum was in need of
reformation, that there ought to be more fraternity and correspondence
among the universities of Europe, and they even contemplated the
endowment by the State of scientific experiment. They spoke of erecting
a university at London, where Gresham College had been established in
1597 and Chelsea College in 1610. It was proposed to place Gresham
College, the Savoy, or Winchester College, at the disposition of the
pansophists. Comenius thought that nothing was more certain than that
the design of the great Verulam concerning the opening somewhere of a
universal college, devoted to the advancement of the sciences, could be
carried out. The impending struggle, however, between Charles I and the
Parliament prevented the attempt to realize the pansophic dream, and the
Austrian Slav, who knew something of the horrors of civil war, withdrew,
discouraged, to the Continent.
Nevertheless, Hartlib did not abandon the cause, but in 1644 broached
Milton on the subject of educational reform, and drew from him the brief
but influential tract on _Education_. In this its author alludes rather
slightingly to Comenius, who had something of Bacon's infelicity in
choice of titles and epithets and who must have seemed outlandish to the
author of _Lycidas_ and _Comus_. But Milton joined in the criticism of
the universities--the study of words rather than things--and advocated
an encyclopedic education based on the Greek and Latin writers of a
practical and scientific tendency (Aristotle, Theophrastus, Cato, Varro,
Vitruvius, Seneca, and others). He outlined a plan for the establishment
of an institution to be known by the classical (and Shakespearian) name
"Academy"--a plan destined to have a great effect on education in the
direction indicated by the friends of pansophia.
In this same year Robert Boyle, then an eager student of eighteen just
returned to England from residence abroad, came under the influence of
the genial Hartlib. In 1646 he writes his tutor inquiring about books
on methods of husbandry and referring to the new philosophical college,
which valued no knowledge but as it had a tendency to use. A few months
later he was in correspondence with Hartlib in reference to the
Invisible College, and had written a third friend that the corner-stones
of the invisible, or, as they termed themselves, the philosophical
college, did now and then honor him with their company. These
philosophers whom Boyle entertained, and whose scientific acumen,
breadth of mind, humility, and universal good-will he found so
congenial, were the nucleus of the Royal Society of London, of which, on
its definite organization in 1662, he was the foremost member. They had
begun to meet together in London about 1645, worthy persons inquisitive
into natural philosophy--Wilkins, interested in the navigation of the
air and of waters below the surface; Wallis, mathematician and
grammarian; the many-sided Petty, political economist, and inventor of a
double-bottomed boat, who had as a youth of twenty studied with Hobbes
in Paris in 1643, and in 1648 was to write his first treatise on
industrial education at the suggestion of Hartlib, and finally make a
survey of Ireland and acquire large estates; Foster, professor of
astronomy at Gresham College; Theodore Haak from the Pfalz; a number of
medical men, Dr. Merret, Dr. Ent, a friend of Harvey, Dr. Goddard, who
could always be relied upon to undertake an experiment, Dr. Glisson, the
physiologist, author in 1654 of a treatise on the liver (_De Hepate_),
and others. They met once a week at Goddard's in Wood Street, at the
Bull's Head Tavern in Cheapside, and at Gresham College.
Dr. Wilkins, the brother-in-law of Cromwell, who is regarded by some as
the founder of the Royal Society, removed to Oxford, as Warden of
Wadham, in 1649. Here he held meetings and conducted experiments in
conjunction with Wallis, Goddard, Petty, Boyle, and others, including
Ward (afterwards Bishop of Salisbury) interested in Bulliau's Astronomy;
and the celebrated physician and anatomist, Thomas Willis, author of a
work on the brain (_Cerebri Anatome_), and another on fevers (_De
Febribus_), in which he described epidemic typhoid as it occurred during
the Civil War in 1643.
In the mean time the weekly meetings in London continued, and were
attended when convenient by members of the Oxford group. At Gresham
College by 1658 it was the custom to remain for discussion Wednesdays
and Thursdays after Mr. Wren's lecture and Mr. Rooke's. During the
unsettled state of the country after Cromwell's death there was some
interruption of the meetings, but with the accession of Charles II in
1660 there came a greater sense of security. New names appear on the
records, Lord Brouncker, Sir Robert Moray, John Evelyn, Brereton, Ball,
Robert Hooke, and Abraham Cowley.
[Illustration: _From a print of 1675_
WADHAM COLLEGE, OXFORD]
Plans were discussed for a more permanent form of organization,
especially on November 28, 1660, when something was said of a design to
found a college for the promotion of physico-mathematical experimental
learning. A few months later was published Cowley's proposition for an
endowed college with twenty professors, four of whom should be
constantly traveling in the interests of science. The sixteen resident
professors "should be bound to study and teach all sorts of natural,
experimental philosophy, to consist of the mathematics, mechanics,
medicine, anatomy, chemistry, the history of animals, plants, minerals,
elements, etc.; agriculture, architecture, art military, navigation,
gardening; the mysteries of all trades and improvement of them; the
facture of all merchandise, all natural magic or divination; and briefly
all things contained in the Catalogue of Natural Histories annexed to my
Lord Bacon's _Organon_." The early official history of the Royal Society
(Sprat, 1667) says that this proposal hastened very much the adoption of
a plan of organization. Cowley wished to educate youth and incur great
expense (£4,000), but "most of the other particulars of his draught the
Royal Society is now putting in practice."
A charter of incorporation was granted in July, 1662; and, later,
Charles II proclaimed himself founder and patron of the Royal Society
for the advancement of natural science. Charles continued to take an
interest in this organization, devoted to the discovery of truth by the
corporate action of men; he proposed subjects for investigation, and
asked their coöperation in a more accurate measurement of a degree of
latitude. He showed himself tactful to take account of the democratic
spirit of scientific investigation, and recommended to the Royal Society
John Graunt, the author of a work on mortality statistics first
published in 1661. Graunt was a shop-keeper of London, and Charles said
that if they found any more such tradesmen, they should be sure to admit
them all without more ado.
It was a recognized principle of the Society freely to admit men of
different religions, countries, professions. Sprat said that they openly
professed, not to lay the foundation of an English, Scotch, Irish,
Popish or Protestant philosophy, but a philosophy of mankind. They
sought (hating war as most of them did) to establish a universal
culture, or, as they phrased it, a constant intelligence throughout all
civil nations. Even for the special purposes of the Society, hospitality
toward all nations was necessary; for the ideal scientist, the perfect
philosopher, should have the diligence and inquisitiveness of the
northern nations, and the cold and circumspect and wary disposition of
the Italians and Spaniards. Haak from the German Palatinate was one of
the earliest Fellows of the Society, and is even credited by Wallis with
being the first to suggest the meetings of 1645. Oldenburg from Bremen
acted as secretary (along with Wilkins) and carried on an extensive
foreign correspondence. Huygens of Holland was one of the original
Fellows in 1663, while the names of Auzout, Sorbière, the Duke of
Brunswick, Bulliau, Cassini, Malpighi, Leibnitz, Leeuwenhoek (as well as
Winthrop and Roger Williams) appear in the records of the Society within
the first decade. It seemed fitting that this cosmopolitan organization
should be located in the world's metropolis rather than in a mere
university town. Sprat thought London the natural seat of a universal
philosophy.
As already implied, the Royal Society was not exclusive in its attitude
toward the different vocations. A spirit of true fellowship prevailed in
Gresham College, as the Society was sometimes called. The medical
profession, the universities, the churches, the court, the army, the
navy, trade, agriculture, and other industries were there represented.
Social partition walls were broken down, and the Fellows, sobered by
years of political and religious strife, joined, mutually assisting one
another, in the advance of science for the sake of the common weal.
Their express purpose was the improvement of all professions from the
highest general to the lowest artisan. Particular attention was paid to
the trades, the mechanic arts, and the fostering of inventions. One of
their eight committees dealt with the histories of trades; another was
concerned with mechanical inventions, and the king ordained in 1662 that
no mechanical device should receive a patent before undergoing
their scrutiny. A great many inventions emanated from the Fellows
themselves--Hooke's hygroscope; Boyle's hydrometer, of use in the
detection of counterfeit coin; and, again, the tablet anemometer used by
Sir Christopher Wren (the Leonardo da Vinci of his age) to register the
velocity of the wind. A third committee devoted itself to agriculture,
and in the Society's museum were collected products and curiosities of
the shop, mine, sea, etc. One Fellow advised that attention should be
paid even to the least and plainest of phenomena, as otherwise they
might learn the romance of nature rather than its true history. So bent
were they on preserving a spirit of simplicity and straightforwardness
that in their sober discussions they sought to employ the language of
artisans, countrymen, and merchants rather than that of wits and
scholars.
Of course there was in the Society a predominance of gentlemen of means
and leisure, "free and unconfined." Their presence was thought to serve
a double purpose. It checked the tendency to sacrifice the search of
truth to immediate profit, and to lay such emphasis on application, as,
in the words of a subsequent president of the Society, would make truth,
and wisdom, and knowledge of no importance for their own sakes. In the
second place their presence was held to check dogmatism on the part of
the leaders, and subservience on the part of their followers. They
understood how difficult it is to transmit knowledge without putting
initiative in jeopardy and that quiet intellect is easily dismayed in
the presence of bold speech. The Society accepted the authority of no
one, and adopted as its motto _Nullius in Verba_.
In this attitude they were aided by their subject and method. Search for
scientific truth by laboratory procedure does not favor dogmatism. The
early meetings were taken up with experiments and discussions. The
Fellows recognized that the mental powers are raised to a higher degree
in company than in solitude. They welcomed diversity of view and the
common-sense judgment of the onlooker. As in the Civil War the private
citizen had held his own with the professional soldier, so here the
contribution of the amateur to the discussion was not to be despised.
They had been taught to shun all forms of narrowness and intolerance.
They wished to avoid the pedantry of the mere scholar, and the allied
states of mind to which all individuals are liable; they valued the
concurring testimony of the well-informed assembly. In the investigation
of truth by the experimental method they even arrived at the view that
"true experimenting has this one thing inseparable from it, never to be
a fixed and settled art, and never to be limited by constant rules." In
its incipience at least it is evident that the Royal Society was filled
with the spirit of tolerance and coöperation, and was singularly free
from the spirit of envy and faction.
Not least important of the joint labors of the Society were its
publications, which established contacts and stimulated research
throughout the scientific world. Besides the _Philosophical
Transactions_, which, since their first appearance in 1665, are the most
important source of information concerning the development of modern
science, the Royal Society printed many important works, among which the
following will indicate its early achievements:--
Hooke, Robert, _Micrographia: or some Physiological Descriptions of
Minute Bodies made by Magnifying Glasses_. 1665.
Graunt, John, _Natural and Political Observations ... made upon the
Bills of Mortality, with reference to the Government, Religion,
Trade, Growth, Air, Diseases, and the several changes of the City_.
3d edition, 1665.
Sprat, Thomas, _The History of the Royal Society of London, for the
Improving of Natural Knowledge_. 1667.
Malpighi, Marcello, _Dissertatio epistolica de Bombyce; Societati Regiæ
Londini dicata_. 1669. (On the silkworm.)
Evelyn, John, _Sylva, or a Discourse of Forest Trees_. 1670.
Horrocks, Jeremiah, _Opera [Astronomica] postuma_. 1673.
Malpighi, Marcello, _Anatome Plantarum_. 1675.
Willughby, Francis, _Ornithology_ (revised by John Ray). 1676.
Evelyn, John, _A Philosophical Discourse of Earth, relating to the
Culture and Improvement of it for Vegetation_. 1676.
Grew, Nehemiah, _The Anatomy of Plants_. 1682.
Willughby, F., _Historia Piscium_. 1686.
Ray, John, _Historia Plantarum_. 2 vols., 1686-88.
Flamsteed, John, _Tide-Table for 1687_.
Newton, Isaac, _Philosophiæ Naturalis Principia Mathematica_. Autore
Is. Newton. Imprimatur: S. Pepys, Reg. Soc. Præses. Julii 5, 1686.
4to. Londini, 1687.
After the Society had ordered that Newton's _Mathematical Principles of
Natural Philosophy_ should be printed, it was found that the funds had
been exhausted by the publication of Willughby's book on fishes. It was
accordingly agreed that Halley should undertake the business of looking
after it, and printing it at his own charge, which he had engaged to do.
Shortly after, the President of the Royal Society, Mr. Samuel Pepys, was
desired to license Mr. Newton's book.
It was not merely by defraying the expense of publication that Halley
contributed to the success of the _Principia_. He, Wren, Hooke, and
other Fellows of the Royal Society, concluded in 1684 that if Kepler's
third law were true, then the attraction exerted on the different
planets would vary inversely as the square of the distance. What, then,
would be the orbit of a planet under a central attraction varying as the
inverse square of the distance? Halley found that Newton had already
determined that the form of the orbit would be an ellipse. Newton had
been occupied with the problem of gravitation for about eighteen years,
but until Halley induced him to do so, had hesitated, on account of
certain unsettled points, to publish his results.
He writes: "I began (1666) to think of gravity extending to the orb of
the moon, ... and thereby compared the force requisite to keep the moon
in her orb with the force of gravity at the surface of the earth, and
found them answer pretty nearly." As early as March of that same year
Hooke had communicated to the Society an account of experiments in
reference to the force of gravity at different distances from the
surface of the earth, either upwards or downwards. At this and at every
point in Newton's discovery the records of co-workers are to be found.
By Flamsteed, the first Royal Astronomer, were supplied more accurate
data for the determination of planetary orbits. To Huygens Newton was
indebted for the laws of centrifugal force. Two doubts had made his
meticulous mind pause--one, of the accuracy of the data in reference to
the measurement of the meridian, another, of the attraction of a
spherical shell upon an external point. In the first matter the Royal
Society, as we have seen, had been long interested, and Picard, who had
worked on the measurement of the earth under the auspices of the
Académie des Sciences, brought his results, which came to the attention
of Newton, before the Royal Society in 1672. The second difficulty was
solved by Newton himself in 1685, when he proved that a series of
concentric spherical shells would act on an external point as if their
mass were concentrated at the center. For his calculations henceforth
the planets and stars, comets and all other bodies are points acted on
by lines of force, and "Every particle of matter in the universe
attracts every other particle with a force varying inversely as the
square of their mutual distances, and directly as the mass of the
attracting particle." He deduced from this law that the earth must be
flattened at the poles; he determined the orbit of the moon and of
comets; he explained the precession of the equinoxes, the semi-diurnal
tides, the ratio of the mass of the moon and the earth, of the sun and
the earth, etc. No wonder that Laplace considered that Newton's
_Principia_ was assured a preëminence above all the other productions of
the human intellect. It is no detraction from Newton's merit to say that
Halley, Hooke, Wren, Huygens, Bulliau, Picard, and many other
contemporaries (not to mention Kepler and _his_ predecessors), as well
as the organizations in which they were units, share the glory of the
result which they coöperated to achieve. On the contrary, he seems much
more conspicuous in the social firmament because, in spite of the
austerity and seeming independence of his genius, he formed part of a
system, and was under its law.
[Illustration: _Portrait by John Van der Bank_ _By permission of W. A.
Maxwell & Co._
SIR ISAAC NEWTON]
Shortly after the founding of the Royal Society, correspondence, for
which a committee was appointed, had been adopted as a means of gaining
the coöperation of men and societies elsewhere. Sir John Moray, as
President, wrote to Monsieur de Monmort, around whom, after the death of
Mersenne, the scientific coterie in Paris had gathered. This group of
men, which toward the close of the seventeenth century regarded itself,
not unnaturally, as the parent society, was in 1666 definitely organized
as the Académie Royale des Sciences. Finally, Leibnitz, who had been a
Fellow of the Royal Society as early as 1673, and had spent years in
the service of the Dukes of Brunswick, was instrumental in the
establishment in 1700 of the Prussian Akademie der Wissenschaften at
Berlin.
REFERENCES
Sir David Brewster, _Memoirs of Sir Isaac Newton_.
E. Conradi, Learned Societies and Academies in Early Times,
_Pedagogical Seminary_, vol. XII (1905), pp. 384-426.
Abraham Cowley, _A Proposition for the Advancement of Experimental
Philosophy_.
D. Masson, _Life of Milton_. Vol. III, chap. II.
Thomas Sprat, _The History of the Royal Society of London_.
_The Record of the Royal Society_ (third edition, 1912).
CHAPTER IX
SCIENCE AND THE STRUGGLE FOR LIBERTY--BENJAMIN FRANKLIN
Of the Fellows of the Royal Society, Benjamin Franklin (1706-1790) is
the most representative of that age of enlightenment which had its
origin in Newton's _Principia_. Franklin represents the eighteenth
century in his steadfast pursuit of intellectual, social, and political
emancipation. And in his long fight, calmly waged, against the forces of
want, superstition, and intolerance, such as still hamper the
development of aspiring youth in America, England, and elsewhere, he
found science no mean ally.
There is some reason for believing that the Franklins (_francus_--free)
were of a free line, free from that vassalage to an overlord, which in
the different countries of Europe did not cease to exist with the Middle
Ages. For hundreds of years they had lived obscurely near Northampton.
They had early joined the revolt against the papal authority. For
generations they were blacksmiths and husbandmen. Franklin's
great-grandfather had been imprisoned for writing satirical verses about
some provincial magnate. Of the grandfather's four sons the eldest
became a smith, but having some ingenuity and scholarly ability turned
conveyancer, and was recognized as able and public-spirited. The other
three were dyers. Franklin's father Josiah and his Uncle Benjamin were
nonconformists, and conceived the plan of emigrating to America in
order to enjoy their way of religion with freedom.
Benjamin, born at Boston, twenty-one years after his father's
emigration, was the youngest of ten sons, all of whom were eventually
apprenticed to trades. The father was a man of sound judgment who
encouraged sensible conversation in his home. Uncle Benjamin, who did
not emigrate till much later, showed interest in his precocious
namesake. Both he and the maternal grandfather expressed in verse
dislike of war and intolerance, the one with considerable literary
skill, the other with a good deal of decent plainness and manly freedom,
as his grandson said.
Benjamin was intended as a tithe to the Church, but the plan was
abandoned because of lack of means to send him to college. After one
year at the Latin Grammar School, and one year at an arithmetic and
writing school, for better or worse, his education of that sort ceased;
and at the age of ten he began to assist in his father's occupation, now
that of tallow-chandler and soap-boiler. He wished to go to sea, and
gave indications of leadership and enterprise. His father took him to
visit the shops of joiners, bricklayers, turners, braziers, cutlers, and
other artisans, thus stimulating in him a delight in handicraft.
Finally, because of a bookish turn he had been exhibiting, the boy was
bound apprentice to his brother James, who about 1720 began to publish
the _New England Courant_, the fourth newspaper to be established in
America.
Among the books early read by Benjamin Franklin were _The Pilgrim's
Progress_, certain historical collections, a book on navigation, works
of Protestant controversy, Plutarch's _Lives_, filled with the spirit
of Greek freedom, Dr. Mather's _Bonifacius_, and Defoe's _Essay on
Projects_. The last two seemed to give him a way of thinking, to adopt
Franklin's phraseology, that had an influence on some of the principal
events of his life. Defoe, an ardent nonconformist, educated in one of
the Academies (established on Milton's model) and especially trained in
English and current history, advocated among other projects a military
academy, an academy for improving the vernacular, and an academy for
women. He thought it barbarous that a civilized and Christian country
should deny the advantages of learning to women. They should be brought
to read books and especially history. Defoe could not think that God
Almighty had made women so glorious, with souls capable of the same
accomplishments with men, and all to be only stewards of our houses,
cooks, and slaves.
Benjamin still had a hankering for the sea, but he recognized in the
printing-office and access to books other means of escape from the
narrowness of the Boston of 1720. Between him and another bookish boy,
John Collins, arose an argument in reference to the education of women.
The argument took the form of correspondence. Josiah Franklin's
judicious criticism led Benjamin to undertake the well-known plan of
developing his literary style.
Passing over his reading of the _Spectator_, however, it is remarkable
how soon his mind sought out and assimilated its appropriate
nourishment, Locke's _Essay on the Human Understanding_, which began the
modern epoch in psychology; the _Port Royal Logic_, prepared by that
brilliant group of noble Catholics about Pascal; the works of Locke's
disciple Collins, whose _Discourse on Freethinking_ appeared in 1713;
the ethical writings (1708-1713) of Shaftesbury, who defended liberty
and justice, and detested all persecution. A few pages of translation of
Xenophon's _Memorabilia_ gave him a hint as to Socrates' manner of
discussion, and he made it his own, and avoided dogmatism.
Franklin rapidly became expert as a printer, and early contributed
articles to the paper. His brother, however, to whom he had been bound
apprentice for a period of nine years, humiliated and beat him. Benjamin
thought that the harsh and tyrannical treatment he received at this time
was the means of impressing him with that aversion to arbitrary power
that stuck to him through his whole life. He had a strong desire to
escape from his bondage, and, after five years of servitude, found the
opportunity. James Franklin, on account of some offensive utterances in
the _New England Courant_, was summoned before the Council and sent to
jail for one month, during which time Benjamin, in charge of the paper,
took the side of his brother and made bold to give the rulers some rubs.
Later, James was forbidden to publish the paper without submitting to
the supervision of the Secretary of the Province. To evade the
difficulty the _New England Courant_ was published in Benjamin's name,
James announcing his own retirement. In fear that this subterfuge might
be challenged, he gave Benjamin a discharge of his indentures, but at
the same time signed with him a new secret contract. Fresh quarrels
arose between the brothers, however, and Benjamin, knowing that the
editor dared not plead before court the second contract, took upon
himself to assert his freedom, a step which he later regretted as not
dictated by the highest principle.
Unable to find other employment in Boston, condemned by his father's
judgment in the matter of the contract, somewhat under public criticism
also for his satirical vein and heterodoxy, Franklin determined to try
his fortunes elsewhere. Thus, at the age of seventeen he made his escape
from Boston.
Unable to find work in New York, he arrived after some difficulties in
Philadelphia in October, 1723. He had brought no recommendations from
Boston; his supply of money was reduced to one Dutch dollar and a
shilling in copper. But he that hath a Trade hath an Estate (as Poor
Richard says). His capital was his industry, his skill as a printer, his
good-will, his shrewd powers of observation, his knowledge of books, and
ability to write. Franklin, recognized as a promising young man by the
Governor, Sir William Keith, as previously by Governor Burnet of New
York, had a growing sense of personal freedom and self-reliance.
But increased freedom for those who deserve it means increased
responsibility; for it implies the possibility of error. Franklin,
intent above all on the wise conduct of life, was deeply perturbed in
his nineteenth and twentieth years by a premature engagement, in which
his ever-passionate nature had involved him, by his failure to pay over
money collected for a friend, and by the unsettled state of his
religious and ethical beliefs. Encouraged by Keith to purchase the
equipment for an independent printing-office, Franklin, though unable to
gain his father's support for the project, went to London (for the
ostensible purpose of selecting the stock) at the close of the year
1724.
He remained in London a year and a half, working in two of the leading
printing establishments of the metropolis, where his skill and
reliability were soon prized. He found the English artisans of that time
great guzzlers of beer, and influenced some of his co-workers to adopt
his own more abstinent and hygienic habits of eating and drinking. About
this time a book, _Religion of Nature Delineated_, by William Wollaston
(great-grandfather of the scientist Wollaston) so roused Franklin's
opposition that he wrote a reply, which he printed in pamphlet form
before leaving London in 1726, and the composition of which he
afterwards regretted.
He returned to Philadelphia in the employ of a Quaker merchant, on whose
death he resumed work as printer under his former employer. He was given
control of the office, undertook to make his own type, contrived a
copper-plate press, the first in America, and printed paper money for
New Jersey. The substance of some lectures in defense of Christianity,
in courses endowed by the will of Robert Boyle, made Franklin a Deist.
At the same time his views on moral questions were clarified, and he
came to recognize that truth, sincerity, and integrity were of the
utmost importance to the felicity of life. What he had attained by his
own independent thought rendered him ultimately more careful rather than
more reckless. He now set value on his own character, and resolved to
preserve it.
In 1727, still only twenty-one, he drew together a number of young men
in a sort of club, called the "Junto," for mutual benefit in business
and for the discussion of morals, politics, and natural philosophy. They
professed tolerance, benevolence, love of truth. They discussed the
effect on business of the issue of paper money, various natural
phenomena, and kept a sharp look-out for any encroachment on the rights
of the people. It is not unnatural to find that in a year or two (1729),
after Franklin and a friend had established a printing business of their
own and acquired the _Pennsylvania Gazette_, the young politician
championed the cause of the Massachusetts Assembly against the claims
first put forward by Governor Burnet, and that he used spirited language
referring to America as a nation and clime foreign to England.
In 1730 Franklin bought out his partner, and in the same year published
dialogues in the Socratic manner in reference to virtue and pleasure,
which show a rapid development in his general views. About the same time
he married, restored the money that had long been owing, and formulated
his ethical code and religious creed. He began in 1732 the _Poor Richard
Almanacks_, said to offer in their homely wisdom the best course in
existence in practical morals.
As early as 1729 Franklin had published a pamphlet on _Paper Currency_.
It was a well-reasoned discussion on the relation of the issue of paper
currency to rate of interest, land values, manufactures, population, and
wages. The want of money discouraged laboring and handicraftsmen. One
must consider the nature and value of money in general. This essay
accomplished its purpose in the Assembly. It was the first of those
contributions which, arising from Franklin's consideration of the social
and industrial circumstances of the times, gained for him recognition as
the first American economist. It was in the same spirit that in 1751 he
discussed the question of population after the passage of the British
Act forbidding the erection or the operation of iron or steel mills in
the colonies. Science for Franklin was no extraneous interest; he was
all of a piece, and it was as a citizen of Philadelphia he wrote those
essays that commanded the attention of Adam Smith, Malthus, and Turgot.
In 1731 he was instrumental in founding the first of those public
libraries, which (along with a free press) have made American tradesmen
and farmers as intelligent, in Franklin's judgment, as most gentlemen
from other countries, and contributed to the spirit with which they
defended their liberties. The diffusion of knowledge became so general
in the colonies that
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