Laws and Hypotheses for Behavior 269 



to A D instead of the original A B C D, the law of the 



resolution of physiological states would be relevant to only a 

 fraction of learning. For example, let a cat or dog be given 

 an ordinary discrimination experiment, but so modified 

 that whether the animal responds by the ' right' or the 

 1 wrong' act he is removed immediately after the reward or 

 punishment. That is, the event is either S Ri or S R2, 

 never S Ri R2. Let the experiment be repeated at inter- 

 vals so long that the physiological state, St. Ri, or St. R2, 

 leading to the response Ri or R2 in the last trial, has 

 ceased before the next. The animal will come to respond to 

 S by R2 only, though R2 has never been reached by the 

 ' resolution' of S Ri R2. 



Cats in jumping for birds or mice, men in playing 

 billiards, tennis or golf, and many other animals in many 

 other kinds of behavior, often learn as the dog must in 

 this experiment. The situation on different occasions is 

 followed by different responses, but by only one per 

 occasion. Professor Jennings was misled by treating as 

 general the special case where the situation itself includes a 

 condition of discomfort terminable only by a ' successful' 

 response or by the animal's exhaustion or death. 



Assuming as typical this same limited case of response 

 to an annoying situation, so that success consists simply 

 in replacing the situation by another, Stevenson Smith 

 reduces the learning-process to the law of exercise alone. 

 He argues that, 



"For instance, let an organism at birth be capable of 

 giving N reactions (a, b, c, . . . N) to a definite stimulus 

 S and let only one of these reactions be appropriate. If 

 only one reaction can be given at a time and if the one 

 given is determined by the state of the organism at the 

 time S is received, there is one chance in N that it is the 



