384 Journal of Comparative Neurology and Psychology. 



ogy is legitimate because we directly observe our own mental 

 states introspectively, whereas comparative psychology is illegiti- 

 mate because direct observation is not possible amounts to a 

 denial of even the possibility of a natural history of mind. That 

 such a denial should come from biologists is surprising, yet the 

 fact remains that to-day the strongest opponents as well as the 

 most able supporters of comparative psychology are biologists. 

 Unfortunately those biologists who dispute the legitimacy of a 

 science of mental life overlook the fact that the human mind is the 

 maker of science. 



That there can be no criterion of consciousness in the sense of 

 proof I freely admit. We treat animals as if they were conscious, 

 hence, the reason for a science of mind-in-nature. Merely "ac- 

 knowledging,"' that other animals are conscious does not furnish 

 us with the necessary materials for a genetic formula nor yet for 

 the description of the experience of any particular animal at a 

 given moment. It gives us our starting point, but we must em- 

 ploy signs of mind in the process of gathering together the mate- 

 rials of comparative psychology. The nature of certain of the signs 

 which are available at present I have already discussed briefly else- 

 where.^ We may distinguish two groups: the structural and the 

 functional. Together the facts which we bring under these 

 rubrics constitute the bases for our inferences concerning con- 

 sciousness. 



Claparede has expressed much the same view as is here pre- 

 sented, but I disagree with the assumption upon which he bases 

 his discussion, while agreeing with the following conclusion. 

 "Biology should work simultaneously according to two parallel 

 methods each of which has its advantages and disadvantages, but 

 which are mutually complementary; the ascending or physiological 

 method, which setting out from the amoeba, from the plant, even 

 from the mineral, strives in mounting little by little the ladder of 

 life, to explain the motor manifestations which it encounters by 

 referring them to physico-chemical mechanisms . . . The other 

 method which maybe called the^^j'c^n^/n^orpsychological method, 

 starts from man, from ourselves, in whom conscious states are 

 indisputable, and tries to give account in psychological language of 



'MiJNSTERBERG, H. GrundzUge dcr Psychologic. Leipzig. 1900. Bd. i, S. 98-99. 

 -Yerkes, R. M. Animal Psychology and Criteria of the Psychic. Jour, of Phil. Psy. and Sc. 

 Method. Vol. 2, pp. 141-49- 1905. 



