30 The Animal Mind 



we argue from our own experience. While that portion 

 of our own behavior which involves consciousness shows 

 more irregularity than the portion which does not, yet the 

 causes of the irregularity are often clearly to be found in 

 physiological conditions with which consciousness has noth- 

 ing to do. There are days when we can think clearly and 

 recall easily, and days when obscurities refuse to vanish 

 and the right word refuses to come; days when we are 

 irritable and days when we are sluggish. Yet since we can 

 find nothing in our mental processes to account for this 

 variabihty, it would be absurd to take analogous fluctua- 

 tions in animal behavior as evidence of mind. So com- 

 plicated a machine as an animal organism, even if it be 

 nothing more than a machine, must show irregularities 

 in its working. 



Behavior, then, must be variable, but not merely variable, 

 to give evidence of mind. The criterion most frequently 

 / applied to determine the presence or absence of the psychic 

 J is a variation in behavior that shows definitely the result of 

 previous individual experience. "Does the organism," says 

 Romanes, " learn to make new adjustments, or to modify old 

 ones, in accordance with the results of its own individual ex- 

 perience?" (641, p. 4). Loeb declared that "the funda- 

 mental process which occurs in all psychic phenomena as 

 the elemental component" is "the activity of the as- 

 sociative memory, or of association," and defines asso- 

 ciative memory as "that mechanism by which a stimulus 

 brings about not only the effects which its nature and the 

 specific structure of the irritable organ call for, but by 

 which it brings about also the effects of other stimuli which 

 formerly acted upon the organism almost or quite simulta- 

 neously with the stimulus in question." "If an animal 

 can be trained," he continued, "if it can learn, it possesses 



