



Produced by Charles Keller





A HISTORY OF SCIENCE

BY HENRY SMITH WILLIAMS, M.D., LL.D.

ASSISTED BY EDWARD H. WILLIAMS, M.D.

IN FIVE VOLUMES

VOLUME II.



CONTENTS

   BOOK II

   CHAPTER I. SCIENCE IN THE DARK AGE

   CHAPTER II. MEDIAEVAL SCIENCE AMONG THE ARABIANS

   CHAPTER III. MEDIAEVAL SCIENCE IN THE WEST

   CHAPTER IV. THE NEW COSMOLOGY--COPERNICUS TO KEPLER AND GALILEO

   CHAPTER V. GALILEO AND THE NEW PHYSICS

   CHAPTER VI. TWO PSEUDO-SCIENCES--ALCHEMY AND ASTROLOGY

   CHAPTER VII. FROM PARACELSUS TO HARVEY

   CHAPTER VIII. MEDICINE IN THE SIXTEENTH AND SEVENTEENTH CENTURIES

   CHAPTER IX. PHILOSOPHER-SCIENTISTS AND NEW INSTITUTIONS OF
   LEARNING

   CHAPTER X. THE SUCCESSORS OF GALILEO IN PHYSICAL SCIENCE

   CHAPTER XI. NEWTON AND THE COMPOSITION OF LIGHT

   CHAPTER XII. NEWTON AND THE LAW OF GRAVITATION

   CHAPTER XIII. INSTRUMENTS OF PRECISION IN THE AGE OF NEWTON

   CHAPTER XIV. PROGRESS IN ELECTRICITY FROM GILBERT AND VON
   GUERICKE TO FRANKLIN

   CHAPTER XV. NATURAL HISTORY TO THE TIME OF LINNAEUS

   APPENDIX




A HISTORY OF SCIENCE




BOOK II. THE BEGINNINGS OF MODERN SCIENCE

The studies of the present book cover the progress of science from the
close of the Roman period in the fifth century A.D. to about the middle
of the eighteenth century. In tracing the course of events through so
long a period, a difficulty becomes prominent which everywhere besets
the historian in less degree--a difficulty due to the conflict between
the strictly chronological and the topical method of treatment. We must
hold as closely as possible to the actual sequence of events, since,
as already pointed out, one discovery leads on to another. But, on the
other hand, progressive steps are taken contemporaneously in the various
fields of science, and if we were to attempt to introduce these
in strict chronological order we should lose all sense of topical
continuity.

Our method has been to adopt a compromise, following the course of a
single science in each great epoch to a convenient stopping-point, and
then turning back to bring forward the story of another science. Thus,
for example, we tell the story of Copernicus and Galileo, bringing the
record of cosmical and mechanical progress down to about the middle
of the seventeenth century, before turning back to take up the
physiological progress of the fifteenth and sixteenth centuries. Once
the latter stream is entered, however, we follow it without interruption
to the time of Harvey and his contemporaries in the middle of the
seventeenth century, where we leave it to return to the field of
mechanics as exploited by the successors of Galileo, who were also the
predecessors and contemporaries of Newton.

In general, it will aid the reader to recall that, so far as
possible, we hold always to the same sequences of topical treatment of
contemporary events; as a rule we treat first the cosmical, then the
physical, then the biological sciences. The same order of treatment will
be held to in succeeding volumes.

Several of the very greatest of scientific generalizations are developed
in the period covered by the present book: for example, the Copernican
theory of the solar system, the true doctrine of planetary motions,
the laws of motion, the theory of the circulation of the blood, and the
Newtonian theory of gravitation. The labors of the investigators of the
early decades of the eighteenth century, terminating with Franklin's
discovery of the nature of lightning and with the Linnaean
classification of plants and animals, bring us to the close of our
second great epoch; or, to put it otherwise, to the threshold of the
modern period.




I. SCIENCE IN THE DARK AGE

An obvious distinction between the classical and mediaeval epochs may be
found in the fact that the former produced, whereas the latter failed
to produce, a few great thinkers in each generation who were imbued with
that scepticism which is the foundation of the investigating spirit; who
thought for themselves and supplied more or less rational explanations
of observed phenomena. Could we eliminate the work of some score or so
of classical observers and thinkers, the classical epoch would seem as
much a dark age as does the epoch that succeeded it.

But immediately we are met with the question: Why do no great original
investigators appear during all these later centuries? We have already
offered a part explanation in the fact that the borders of civilization,
where racial mingling naturally took place, were peopled with
semi-barbarians. But we must not forget that in the centres of
civilization all along there were many men of powerful intellect.
Indeed, it would violate the principle of historical continuity to
suppose that there was any sudden change in the level of mentality of
the Roman world at the close of the classical period. We must assume,
then, that the direction in which the great minds turned was for
some reason changed. Newton is said to have alleged that he made his
discoveries by "intending" his mind in a certain direction continuously.
It is probable that the same explanation may be given of almost every
great scientific discovery. Anaxagoras could not have thought out the
theory of the moon's phases; Aristarchus could not have found out
the true mechanism of the solar system; Eratosthenes could not have
developed his plan for measuring the earth, had not each of these
investigators "intended" his mind persistently towards the problems in
question.

Nor can we doubt that men lived in every generation of the dark age
who were capable of creative thought in the field of science, bad they
chosen similarly to "intend" their minds in the right direction. The
difficulty was that they did not so choose. Their minds had a quite
different bent. They were under the spell of different ideals; all
their mental efforts were directed into different channels. What these
different channels were cannot be in doubt--they were the channels of
oriental ecclesiasticism. One all-significant fact speaks volumes here.
It is the fact that, as Professor Robinson(1) points out, from the time
of Boethius (died 524 or 525 A.D.) to that of Dante (1265-1321 A.D.)
there was not a single writer of renown in western Europe who was not a
professional churchman. All the learning of the time, then, centred in
the priesthood. We know that the same condition of things pertained in
Egypt, when science became static there. But, contrariwise, we have
seen that in Greece and early Rome the scientific workers were largely
physicians or professional teachers; there was scarcely a professional
theologian among them.

Similarly, as we shall see in the Arabic world, where alone there was
progress in the mediaeval epoch, the learned men were, for the most
part, physicians. Now the meaning of this must be self-evident. The
physician naturally "intends" his mind towards the practicalities. His
professional studies tend to make him an investigator of the operations
of nature. He is usually a sceptic, with a spontaneous interest in
practical science. But the theologian "intends" his mind away from
practicalities and towards mysticism. He is a professional believer in
the supernatural; he discounts the value of merely "natural" phenomena.
His whole attitude of mind is unscientific; the fundamental tenets
of his faith are based on alleged occurrences which inductive science
cannot admit--namely, miracles. And so the minds "intended" towards
the supernatural achieved only the hazy mysticism of mediaeval thought.
Instead of investigating natural laws, they paid heed (as, for example,
Thomas Aquinas does in his Summa Theologia) to the "acts of angels,"
the "speaking of angels," the "subordination of angels," the "deeds of
guardian angels," and the like. They disputed such important questions
as, How many angels can stand upon the point of a needle? They argued
pro and con as to whether Christ were coeval with God, or whether he had
been merely created "in the beginning," perhaps ages before the creation
of the world. How could it be expected that science should flourish when
the greatest minds of the age could concern themselves with problems
such as these?

Despite our preconceptions or prejudices, there can be but one answer to
that question. Oriental superstition cast its blight upon the fair field
of science, whatever compensation it may or may not have brought in
other fields. But we must be on our guard lest we overestimate or
incorrectly estimate this influence. Posterity, in glancing backward,
is always prone to stamp any given age of the past with one idea, and to
desire to characterize it with a single phrase; whereas in reality all
ages are diversified, and any generalization regarding an epoch is sure
to do that epoch something less or something more than justice. We
may be sure, then, that the ideal of ecclesiasticism is not solely
responsible for the scientific stasis of the dark age. Indeed, there was
another influence of a totally different character that is too patent
to be overlooked--the influence, namely, of the economic condition of
western Europe during this period. As I have elsewhere pointed
out,(2) Italy, the centre of western civilization, was at this time
impoverished, and hence could not provide the monetary stimulus so
essential to artistic and scientific no less than to material progress.
There were no patrons of science and literature such as the Ptolemies of
that elder Alexandrian day. There were no great libraries; no colleges
to supply opportunities and afford stimuli to the rising generation.
Worst of all, it became increasingly difficult to secure books.

This phase of the subject is often overlooked. Yet a moment's
consideration will show its importance. How should we fare to-day if no
new scientific books were being produced, and if the records of former
generations were destroyed? That is what actually happened in
Europe during the Middle Ages. At an earlier day books were made and
distributed much more abundantly than is sometimes supposed. Bookmaking
had, indeed, been an important profession in Rome, the actual makers of
books being slaves who worked under the direction of a publisher. It was
through the efforts of these workers that the classical works in Greek
and Latin were multiplied and disseminated. Unfortunately the climate of
Europe does not conduce to the indefinite preservation of a book;
hence very few remnants of classical works have come down to us in the
original from a remote period. The rare exceptions are certain papyrus
fragments, found in Egypt, some of which are Greek manuscripts dating
from the third century B.C. Even from these sources the output is
meagre; and the only other repository of classical books is a single
room in the buried city of Herculaneum, which contained several hundred
manuscripts, mostly in a charred condition, a considerable number of
which, however, have been unrolled and found more or less legible. This
library in the buried city was chiefly made up of philosophical works,
some of which were quite unknown to the modern world until discovered
there.

But this find, interesting as it was from an archaeological stand-point,
had no very important bearing on our knowledge of the literature of
antiquity. Our chief dependence for our knowledge of that literature
must still be placed in such copies of books as were made in the
successive generations. Comparatively few of the extant manuscripts are
older than the tenth century of our era. It requires but a momentary
consideration of the conditions under which ancient books were produced
to realize how slow and difficult the process was before the invention
of printing. The taste of the book-buying public demanded a clearly
written text, and in the Middle Ages it became customary to produce a
richly ornamented text as well. The script employed being the prototype
of the modern printed text, it will be obvious that a scribe could
produce but a few pages at best in a day. A large work would therefore
require the labor of a scribe for many months or even for several years.
We may assume, then, that it would be a very flourishing publisher who
could produce a hundred volumes all told per annum; and probably there
were not many publishers at any given time, even in the period of Rome's
greatest glory, who had anything like this output.

As there was a large number of authors in every generation of the
classical period, it follows that most of these authors must have been
obliged to content themselves with editions numbering very few copies;
and it goes without saying that the greater number of books were never
reproduced in what might be called a second edition. Even books that
retained their popularity for several generations would presently fail
to arouse sufficient interest to be copied; and in due course such works
would pass out of existence altogether. Doubtless many hundreds of books
were thus lost before the close of the classical period, the names of
their authors being quite forgotten, or preserved only through a chance
reference; and of course the work of elimination went on much more
rapidly during the Middle Ages, when the interest in classical
literature sank to so low an ebb in the West. Such collections of
references and quotations as the Greek Anthology and the famous
anthologies of Stobaeus and Athanasius and Eusebius give us glimpses
of a host of writers--more than seven hundred are quoted by Stobaeus--a
very large proportion of whom are quite unknown except through these
brief excerpts from their lost works.

Quite naturally the scientific works suffered at least as largely as
any others in an