230 THE POPULAR SCIENCE MONTHLY. 



science, I fear that to some of you I must in many places have been 

 very hard to follow. But as a general outcome of the whole lecture — 

 as the great and vivifying principle by which all the facts are more or 

 less connected, and made to spring into a living body of philosophic 

 truth — I will ask you to retain in your memories one cardinal conclu- 

 sion. We are living in a generation which has witnessed a revolution 

 of thought unparalleled in the hisiory of our race. I do not merely 

 allude to the fact that this is a generation in which all the sciences, 

 without exception, have made a leap of progress such as widely to sur- 

 pass all pi-evious eras of intellectual activity ; but I allude to the fact 

 that in the special science of biology it has been reserved for us to see 

 the first rational enunciation, the first practical demonstration, and the 

 first general acceptance, of the doctrine of evolution. And I allude to 

 this fact as to a fact of unparalleled importance in the history of 

 thought, not only because I know how completely it has transformed 

 the study of life from a mere grouping of disconnected observations to 

 a rational tracing of fundamental principles, but also because it is now 

 plainly to be foreseen that what the philosophy of evolution has already 

 accomplished is but an earnest of what it is destined to achieve. "We 

 know the results which have followed in the science of astronomy by 

 the mathematical proof of tfee law of gravitation ; and can we doubt 

 that even more important results will follow in the much more complex 

 science of biology from the practical proof of the law of evolution ? I 

 at least can entertain no doubt on this head ; and, forasmuch as this 

 enormous change in our means of knowledge and our modes of thought 

 has been so largely due to the almost unaided labors of a single man, I 

 do not hesitate to say, even before so critical an audience as this, that 

 in all the history of science there is no single name worthy of a venera- 

 tion more profound than the now immortal name of Charles Darwin. 



Do you ask me why I close this lecture with such a panegyric on 

 the philosophy of evolution ? My answer is : If we have found that in 

 the study of life the theory of descent is the key-note by which all the 

 facts of our science are brought into harmonious relation, we cannot 

 doubt that in our study of mind the theory of descent must be of an 

 importance no less fundamental. And, indeed, even in this our time, 

 which is marked by the first opening dawn of the science of psychology, 

 we have but to look with eyes unprejudiced to see that the philosophy 

 of evolution is here like a rising sun of truth, eclipsing all the lesser 

 lights of previous philosophies, dispelling superstitions like vapors born 

 of darkness, and revealing to our gladdened gaze the wonders of a 

 world till now unseen. So that the cardinal conclusion which I desire 

 you to take away, and to retain in your memories long after all the 

 lesser features of this discourse shall have faded from your thoughts, is 

 the conclusion that mind is everywhere one ; and that the study of 

 comparative psychology, no less than the study of comparative anatomy, 

 Las hitherto yielded results in full agreement with that great transfor- 



