'^ff^ff^Jr^^n^f^f^CF^^r^^r^ff^CF^i^f^^^f^ff^f^ € THE C DOGMA € OF EVOLUTION C 3 C ff^ff^ff^ 3 c 3 c LOUIS T. MORE 3 c 3 d<«P<^<is^<^<^<^<:aiP<^=j)<;«P<^aP<taP^s^Qa-g<^<^ THE DOGMA OF EVOLUTION London: Humphrey Milford Oxford University Press THE Dogma of Evolution BY LOUIS TRENCHARD MORE Professor of Physics, University of Cincinnati Author of "The Limitations of Science" 3^ LOUIS CLARK VANUXEM FOUNDATION LECTURES DELIVERED AT PRINCETON UNIVERSITY JANUARY, 1925 PRINCETON PRINCETON UNIFERSirr PRESS 1925 COPYRIGHT, 1 925 Princeton University Press Second Printing, September 1925 \ Executed at T!he Princeton University Press, Princeton New Jersey The United States of America DEDICATION T'c Mr. and Mrs. Charles Phelps Taft My dear Mr. and Mrs. Taft: In earlier times^ 'which we so complacently call the Dark Ages, those who wished to obtain an insight in- to spiritual mysteries or to learn the fortunate or un- fortunate outcome of their enterprise were wont to consult astrologers. For it was foolishly believed that our spiritual and temporal affairs were determined by the positions and motions of the planets in their orbits. Is it not true that men, today, are seeking the source and law of our spiritual being in the configura- tions and motions of the atoms which compose our corporeal substance? Is there any real difference be- tween the attempts of the ancient astrologers and the 7nodern biologists? Only time will tell. But, whatever cause we assign to our being, every one accepts the fact that friendship is one of the qual- ities nearest to an immaterial source. And I, who am trying to vindicate the belief in our spiritual nature, would wish to offer this book to you who have for so many years given me such abundant proofs of friend- ship in its rarest form. Affectionately yours.. Louis Trenchard More Cincinnati December, 1924 ^a^^*"^'' CONTENTS I. Introduction: Evolution as Science and Faith 1 II. The Greek Attitude towards Science 35 III. The Mediaeval Attitude towards Science 75 IV. Palaeontology and Geology : The Positive Evidence for Evolution 117 V. Lamarck 163 VI. Darwin 185 VII. Life as Mechanism 241 VIII. Evolution and Society 298 IX. Evolution and Religion 346 AHLL^ CHAPTER ONE Introduction Evolution as Science and Faith SINCE the Renaissance, which reached its full de- velopment in Italy during the fifteenth century^ man has fallen more and more under the domination of science and has correspondingly relaxed the author- ity of religion. It is this fundamental change in atti- tude of mind which most distinguishes us from the Middle Ages. Try as we will, we utterly fail to un- derstand the mental state of those who subordinated reason to faith, who regarded the miraculous as more trustworthy than the natural, and who condemned mortal desires as the enemy of the soul. On the other hand the history of civilization, since the Renais- sance, is like the unfolding of the connected biogra- phy of a man from youth to maturity. The rise of modern science may be dated from the publication of the heliocentric system of Copernicus in 1543. The profound change in thought, which the mere substitution of the sun as the centre of our plan- etary system and the ascription of two motions to the earth were destined to produce, was not recognized at first. In fact, the Church did not foresee the theological and social consequences of this theory un- THE DOGMA OF EVOLUTION til they were openly promulgated by Galileo. His trial for heresy, in 1633, first proved how essential to the Aristotelian philosophy of the day and to the dog- mas of the Church was the belief that the earth is the immovable centre of the universe. This trial was the dramatic beginning of the persistent conflict between the scientific attitude which relies on observation and reason as the criteria of truth and the opposing con- viction which holds that truth is revealed by the in- spiration of faith. The leaders of scientific thought, in the sixteenth century, believed that the question involved an or- ganized revolution of method. If the earth, and all it contained, were merely a part of a universe subject solely to mechanical laws and forces, then a death- blow had been given to the dogma of the Church, founded on the inspiration of the Scriptures and on the interpretation of Aristotelian philosophy, that the world was fashioned for man by a Creator and Ruler of the universe who could, and frequently did, supersede natural law. While the verdict of heresy apparently crushed the new movement, it actually focused attention on the deeper aspects of the controversy and created a wider acceptance of Galileo's ideas than they had pre- viously enjoyed. Galileo warns his adversaries not to oppose the interpretation of his observations and ex- periments with the authority of Aristotle. Descartes, on learning the decision of the trial, laid aside the [2 ] INTRODUCTION manuscript of his treatise on a new cosmical system, on the ground that if the world would not accept the mechanical principles of Galileo there was no chance for his far more daring attempt to exalt natural law. Pascal advises us to limit our respect and admiration for the ancient writers. But of all the leaders of the period, Francis Bacon saw most clearly the impend- ing break between modern and ancient times. He re- iterates, over and over again, that the Greek philoso- phers had failed, however brilliantly they may have reasoned, because they had not based their work on observation and experiment. To him the old gospel was dead, and he would give a novum organutn which would install science by inductive reasoning as the guide to truth. This revolt, which began in the sciences of astron- omy and mechanics, spread until it embraced the phenomena of all the inorganic world. But so long as the nature and actions of living organisms, and especially of man, remained outside the laws of phys- ics, the revolution was manifestly incomplete. Dur- ing the nineteenth century, science reached out to in- clude the biological phenomena. The movement against the authority of religion, in this field, takes the form of biological evolution which finds its most frequent expression in Darwinism. It is true that evolution is a much more general term and signifies merely any continuous variation of forms of fauna and flora in contradistinction to the special creation . THE DOGMA OF EVOLUTION of fixed species; while Darwinism is an attempt to discover the causes and method of such variation. Yet, in the popular mind, Darwinism has been so con- fused with evolution that the two are likely to stand or fall together as a philosophical explanation of the problems of society and religion. That the controversy which arose over evolution is a continuation of the earlier revolt accomplished by the physical sciences was thoroughly understood by its leaders. Darwin writes to Lyell : "I was much in- terested by finding accidentally in Brewster's Life of Newton that Leibnitz objected to the law of gravity because Newton could not show what gravity itself is. As it has chanced, I have used in letters this very same argument, little knowing that any one had real- ly thus objected to the law of gravity. Leibnitz further objected that the law of gravity was opposed to Natural Religion I Is this not curious^ I really think I shall use the facts for some introductory re- marks for my bigger book."^ And, as might be expected, Huxley was clearer and more emphatic in linking evolution with physical science. He wrathfully explodes during a defence of the Origin of Species : "I hardly know of a great phys- ical truth, whose universal reception has not been pre- ceded by an epoch in which most estimable persons have maintained that the phenomena investigated 1 Life and Letters of Charles Darwin, by F. Darwin ; Appleton, 1887, vol. II, p. 83. 1:43 INTRODUCTION were directly dependent on the Divine Will, and that the attempt to investigate them was not only futile, but blasphemous. And there is a wonderful tenacity of life about this sort of opposition to physical science. Crushed and maimed in every battle, it yet seems never to be slain; and after a hundred defeats it is at this day as rampant, though happily not so mischievous, as in the time of Galileo. To those who watch the signs of the times, it seems plain that this nineteenth century will see revolutions of thought and practice as great as those which the sixteenth wit- nessed."^ The analogy is the specious one that, because the Galilean revolution was successful, so also Darwin- ism and sociological evolution must be accepted. The fallacy lies in the fact that the physical sciences dealt with a specialized field. Physicists had rigorously ab- stracted from their problems all considerations of what we call life. And they could do this because liv- ing organisms are associated with the physical and chemical machines we call their bodies, and no one has ever doubted that many actions of the body are physical and chemical. Thus, the problem of physics was to find laws of force and energy acting on matter. But, when biology arose, men of science were con- fronted with the fact that the gap between the inor- ganic and the organic worlds must be bridged. In brief, they must show that a dead man is the same as ^Ibid., vol. II, p. 77. THE DOGMA OF EVOLUTION a live one except for certain chemical changes.