Evolution in Modern Thought   By: August Weismann (1834-1914)

THOUGHT

BY HAECKEL, THOMSON, WEISMANN

AND OTHERS

THE MODERN LIBRARY

PUBLISHERS :: :: NEW YORK

CONTENTS

I DARWIN'S PREDECESSORS

J. Arthur Thomson, Professor of Natural History in the University of Aberdeen

II The Selection Theory

August Weismann, Professor of Zoology in the University of Freiburg (Baden)

III HEREDITY AND VARIATION IN MODERN LIGHTS

W. Bateson, Professor of Biology in the University of Cambridge

IV "THE DESCENT OF MAN"

G. Schwalbe, Professor of Anatomy in the University of Strassburg

V CHARLES DARWIN AS AN ANTHROPOLOGIST

Ernst Haeckel, Professor of Zoology in the University of Jena

VI MENTAL FACTORS IN EVOLUTION

C. Lloyd Morgan, Professor of Psychology at University College, Bristol

VII THE INFLUENCE OF THE CONCEPTION OF EVOLUTION ON MODERN PHILOSOPHY

H. Höffding, Professor of Philosophy in the University of Copenhagen

VIII THE INFLUENCE OF DARWIN UPON RELIGIOUS THOUGHT

Rev. P. H. Waggett

IX DARWINISM AND HISTORY

J. B. Bury, Regious Professor of Modern History in the University of Cambridge

X DARWINISM AND SOCIOLOGY

C. Bouglé, Professor of Social Philosophy in the University of Toulouse, and Deputy Professor at the Sorbonne, Paris

EVOLUTION IN MODERN THOUGHT

I

DARWIN'S PREDECESSORS

BY J. ARTHUR THOMSON

Professor of Natural History in the University of Aberdeen

In seeking to discover Darwin's relation to his predecessors it is useful to distinguish the various services which he rendered to the theory of organic evolution.

(I) As everyone knows, the general idea of the Doctrine of Descent is that the plants and animals of the present day are the lineal descendants of ancestors on the whole somewhat simpler, that these again are descended from yet simpler forms, and so on backwards towards the literal "Protozoa" and "Protophyta" about which we unfortunately know nothing. Now no one supposes that Darwin originated this idea, which in rudiment at least is as old as Aristotle. What Darwin did was to make it current intellectual coin. He gave it a form that commended itself to the scientific and public intelligence of the day, and he won widespread conviction by showing with consummate skill that it was an effective formula to work with, a key which no lock refused. In a scholarly, critical, and pre eminently fair minded way, admitting difficulties and removing them, foreseeing objections and forestalling them, he showed that the doctrine of descent supplied a modal interpretation of how our present day fauna and flora have come to be.

(II) In the second place, Darwin applied the evolution idea to particular problems, such as the descent of man, and showed what a powerful organon it is, introducing order into masses of uncorrelated facts, interpreting enigmas both of structure and function, both bodily and mental, and, best of all, stimulating and guiding further investigation. But here again it cannot be claimed that Darwin was original. The problem of the descent or ascent of man, and other particular cases of evolution, had attracted not a few naturalists before Darwin's day, though no one [except Herbert Spencer in the psychological domain (1855)] had come near him in precision and thoroughness of inquiry.