2 BIOLOGICAL LECTURES. 



living things, including man. They were created, at their be- 

 ginning being the same substantially as we see them now to 

 be. There is not and never has been in the history of man 

 any phenomenon that could give warrant to such a hypothesis, 

 yet it has been held and fought for by men now living. 



Then there is another kind of speculation that has or tries 

 to have proper data that shows some respect for experience. 

 Such was the attempt of Robert Chambers in the book called 

 Vestiges of Creation, a book which is deserving of more 

 praise than I have yet seen awarded it, for he undertook to 

 handle such data as were available to him and he discerned 

 dimly the process which all naturalists to-day see clearly. His 

 data were inadequate and could not compel belief, but his at- 

 tempt as compared with the hypothesis it contended against 

 was as daylight to darkness. It had some experience in its 

 favor ; the other had none at all. 



Lastly there is a hypothesis derived from the study of groups 

 of appropriate facts, the attempt to find an adequate explana- 

 tion of all of them, without going beyond the bounds of possi- 

 ble experience, that is, without importing into the phenomena 

 some transcendental conditions. Such is Darwin's Theory of 

 Natural Selection, offered for acceptance as a provisional hy- 

 pothesis thirty-five years ago. Also fought against stubbornly 

 by naturalists as well as theologians in spite of the plain fact that 

 it was either such a hypothesis or nothing ; there was no other 

 competing one that had any standing ground at all, which 

 seems to imply that to some minds it is more rational to enter- 

 tain an unintelligible hypothesis with no experimental data in 

 its favor, than it is to entertain one that has a considerable 

 body of experimental data for its basis. 



Swedenborg taught the nebula hypothesis, but gave no 

 astronomical reasons. Kant developed it, giving philosophical 

 reasons which were not considered to be adequate. Laplace 

 gave mechanical reasons which were adequate, and he who ex- 

 plains that theory to-day gives the reasons of both Kant and 

 Laplace, but he quite ignores Swedenborg. Kepler explained 

 the orbital movements of the planets as due to guiding spirits. 

 Newton explained them by the doctrine of gravitation and dis- 



