68 BIOLOGICAL SOCIETY OF WASHINGTON. 



one, and go on collecting such facts until libraries were filled, and 

 the minds of men buried under their weight, and no addition 

 would be made to philosophy thereby. There must be some method 

 of selecting, some method of determining what facts are valuable, 

 and what facts are trivial. The fool collects facts ; the wise man 

 selects them. 



Amid the multiplicity of facts in the universe, how does the wise 

 man choose for his use? The true scientific man walks not at random 

 through the world making notes of what he sees ; he chooses some 

 narrow field of investigation. Within this field he reviews what 

 is already known and becomes conversant with the conclusions al- 

 ready reached. He then seeks to discern more facts in this field, 

 and to make more careful discriminations therein, and then to make 

 more homologic classifications; and, finally, more thoroughly to dis- 

 cover the complexity of sequences. 



If he attain to success in doing all this his investigations are al- 

 ways suggested by some hypothesis — some supposition of what he 

 may discover. He may find that his hypothesis is wrong, and 

 discover something else; but without an hypothesis he discovers 

 nothing. A scientific man taking up a subject reviews the facts 

 that are known, and imagines that they lead to conclusions that 

 have not yet been reached by others. His imagination may lead 

 him quite astray, yet he follows it, and says "Now if this be true, 

 then there must be certain yet undiscovered facts," and he seeks 

 for them. He may find that which he seeks, or he may find some- 

 thing quite other. If he be an honest thinker, a true philosopher, 

 it matters not to him. He substantiates his hypothesis or con- 

 structs a new one. If such hypothesis leads to many new discov- 

 eries scientific men accept it, and call it a working hypothesis, and 

 if it still leads on to discovery scientific men call it a theory ; and 

 so working hypotheses are developed into theories, "and these 

 theories become the fundamental principles, the major propositions 

 of science, the widest generalizations of philosophy. 



Sometimes the inductive method — the Baconian method — is said 



