SOME EIGHTEENTH CENTURY EVOLUTIONISTS. 3 2 3 



SOME EIGHTEENTH CENTURY EVOLUTIONISTS. II. 



By Professor ARTHUR O. LOVEJOY, 



WASHINGTON UNIVERSITY. 



II. Diderot. — Diderot was in even less degree than Maupertuis a 

 contributor to the details of scientific knowledge; and the contrast 

 between the work of the interpreter and that of the investigator of the 

 facts of science is well shown in the relation of his theories to the dis- 

 coveries of Daubenton. It was the great associate of Buffon who laid 

 the foundations of the science of comparative anatomy, which was to 

 furnish the most important arguments in favor of the theory of evolu- 

 tion; a French writer (Vicq d'Azyr) has even gone so far as to say 

 that ' to the merit of having made a beginning of that science Daubenton 

 has added the merit of having carried it through to completion. ' After 

 the publication of the third and fourth volumes of the 'Histoire 

 Naturelle, ' an important body of facts and comparisons relating to the 

 anatomy of the vertebrates was accessible to all readers ; it is one of the 

 most serious blots upon the reputation of Buffon as a man of science 

 that he failed to appreciate the value of this body of detailed knowledge, 

 and in a subsequent edition of the work cut out Daubenton 's anatomical 

 contributions — to the great grief and disappointment of their author. 

 Now the publication of the main facts of comparative anatomy brought 

 clearly to light the striking homologies that run through the structure 

 of all the vertebrate species. Daubenton himself, however, was not the 

 man to see that these homologies suggested, and went far to justify, 

 the hypothesis of the descent of all such species by progressive varia- 

 tion from a common ancestral prototype. His talent was not for the 

 making of hypotheses, but for the collation of facts ; he was a cautious 

 and conservative man, capable of infinitely patient and accurate 

 observation, but apparently not capable of penetrating to the signifi- 

 cance of the facts which he observed. Even when the evolutionary 

 hypothesis had been put forward by others, he gave it no encourage- 

 ment; and it was apparently with the purpose of combating it that he 

 contributed a paper to the French Academy of Sciences in 1764, 

 arguing that the anatomical differences between man and the orang- 

 outang are radical, and that man's general structure is elaborately 

 adapted to the maintenance of the erect attitude, as the structure of the 

 ape is not ('Memoires de l'Academie des Sciences,' 1764, p. 568). 

 Similarly he argued, in his introduction to the natural-history volume 

 of the ' Encyclopedic Methodique' (1783), that man differs so essentially 



