Difficulties and Methods 23 



that no knowledge whatever of the animal mind is obtain- 

 able? If so,^we must also admit that human psychology is 

 impossible. Our acquaintance with the 'mind of animals 

 rests upon the same basis as our acquaintance with the mind 

 of our fellow-man; both are derived by inference from 

 observed behavior. The actions of our fellow-men resemble 

 our own, and we therefore infer in them like subjective states 

 to ours : the actions of animals resemble ours less completely, 

 "but the difference is one of degree, not of kind. This argu- 

 ment in behalf of comparative psychology, which is brought 

 forward by Claparede (77), is opposed by Nuel with the 

 denial that human and animal psychology rest upon the same 

 basis (297); but no cogent proofs accompany Nuel's state- 

 ment. The physiologists would doubtless accept the other 

 horn of the dilemma, and reject human psychology along with 

 animal psychology ; but a scientific rigor which requires of us 

 to abandon the assertion of mind in our fellow-beings and 

 the study of that mind has pushed itself to absurdity. As 

 Jordan says, inferences upon a basis of probability form a 

 legitimate part of science (216). The mental processes in 

 other minds, animal or human, cannot indeed be objectively 

 ascertained facts ; the facts are those of human and animal 

 behavior; but the mental processes are as justifiable infer- 

 ences as any others with which science deals. The prime 

 necessity is merely that they shall be properly guarded. Cer-X 

 tain precautions are necessary when we infer the state of our j 

 neighbor's mind; certain added precautions are necessary / 

 when we infer states in the mind of an animal, and our asy 

 sertions should certainly diminish in dogmatism as we go 

 down the scale of animal life. But the psychologist, to whom, 

 as Titchener has put it, u the facts and laws of mind are the 

 most real things that the world can show " (400), will never 

 consent to abandon the effort to probe the mysteries of other 



