382 'Journal of Comparative Neurology and Psychology. 



apply it in the description of human visual phenomena resulted in 

 a book which will do much towards preventing its further use. 

 On the whole the results of the use of the system seem to justify 

 the conclusion that clear logical thinking is far more important 

 than the sharp separation of subjective from objective terms. 



Von Uexkull argues, however, that since we can describe the 

 functions of the nervous system and the behavior of an animal in 

 objective terms (a« assumptioii of the possibility of %uhat has not 

 been done, it is to be noted) there is neither scientific justification nor 

 excuse for the assumption that an animal has sense impressions, 

 feels, thinks or wills. The concluding paragraph of his discussion 

 of this matter is my chief excuse for this paper. "Such in a few 

 words are the problems and aspects of experimental biology. A 

 blossoming of this hopeful science is, however, only to be expected 

 when investigators become impressed with the conviction that 

 psychological doctrines in so far as they relate to the animal mind 

 are worthless and untenable speculations, and when refusing to be 

 led astray by the siren tones of theories of mind, they limit their 

 researches to the facts of experience."^ 



There would be no reason to quarrel with von Uexkull were it 

 not that he excludes much of the recognized material of human 

 psychology from "experience." In fact, he frankly says that 

 there can be no science of the mental life of animals because we 

 can have no knowledge of their states of consciousness. Beer, 

 Bethe, Nuel and many other writers on the physiology of the 

 nervous system apparently agree with von Uexkull, and 

 ZiEGLER^ holds a similar position. 



It is not clear that these scientists realize that their denials of the 

 possibility of a science of comparative psychology can be made 

 consistently and logically only if they deny that our inferences con- 

 cerning the conscious states of our fellow beings, human and infra- 

 human, influence our actions. It is almost incredible that any 

 thoughtful person should contend that we are not influenced con- 

 stantly by what we believe to be the feelings, purposes, desires of 

 our fellows, yet precisely this is demanded of those who deny the 

 legitimacy of comparative psychology. 



^Uexkull, J. vox. Psychologic und Biologic in ihrer Stellung zur Tierscele. Ergehnisse der 

 Physiologic. Bd. 1, Abt. 2, S. 233. 1902. 



^ZiEGLER, H. E. Theorctisches zur Tierpsychologie und vergleichenden Neurophysiologie. 

 Biologisches Cetitralblatt. Bd. 20, S. 1-16. 1900. 



