78 BIOLOGICAL LECTURES. 



conduct like it), then, is the result of several associations, the 

 act of one of which brings the animal into the situation of the 

 next. Of such serial associations the chick in the labyrinth 

 showed us a good example. The dog sneezes at our command, 

 because in teaching him we held his nose so as to compel him 

 to sneeze at the same time that we gave the command. The 

 act of sneezing thus became associated with a total situation, 

 including the pressure, etc., at the nostrils and the sound of 

 our command, and was later on committed when the latter part 

 only of the situation was present. 



The behavior of animals under test conditions has, then, 

 shown us a simple associative process following a simple law 

 which seems competent to explain ordinary cases of animal 

 learning. This does not imply that other processes, such as 

 imitation or inference or comparison, may not in some cases 

 mediate between a situation and the animal's reaction to it, that 

 no more complex process than that we have described ever 

 does occur, that this way of profiting by experience is the only 

 way for animals. Decision as to the presence or absence of 

 such processes is not within the province of this paper. Our 

 task so far has been to get a clear idea of what happens in a 

 considerable number of cases of animal learning, and to apply 

 our hypotheses to certain other cases than those from which 

 they were discovered. The task left us is to make some deeper 

 inquiries into the psychology of the process and its possible 

 neural counterpart, to investigate the extent to which such a 

 method of learning prevails down through the animal phylum, 

 the delicacy, complexity, number, and permanence of such asso- 

 ciations, and their importance in keeping the animal alive. 



We have hitherto remained content with the evident fact 

 that pleasant consequences do stamp in the connection between 

 the impulse and act which led to them and the situation in which 

 the impulse was felt. Biologists in general have been ready to 

 accept this fact. In human life it seems indubitable. Yet it 

 compels one to face a very difficult problem, familiar enough 

 to psychology, but seldom thought out by biologists. For 

 pleasurable feelings of taste, freedom, sexual activity, or what 

 not, ViTQ feclijigs ; are not facts of motion in space, are not 



