SOME RESULTS OF EXPERIMENT 139 
as such does not know, because it does not analyze the 
situation and disentangle the essential relationships. The 
satisfaction of success again suffices. In a word, such an 
animal in the perceptual stage of mental development seems 
wanting in the power of reflection. He does not appear to show 
evidence of framing anything like a general scheme of know- 
ledge which he can apply to the solution of particular problems, 
of a practical nature, involving difficulties and obstacles. 
The method of intelligence—in the sense in which we are 
using this term—the method of varied trial and error with the 
utilization of chance success, is a lengthy and somewhat 
clumsy process; but it suffices. Now contrast it with the 
procedure of a rational animal, such as man:is or may be. 
When he is confronted by a difficulty he is not content to meet 
it by trying this way, and that way, and another way, anyhow, 
and trusting to chance to bring success, but he considers the 
problem in all its relations with a view to ascertaining the 
essential nature of the difficulty. For each attempted mode of 
meeting the case he has a definite reason. He knows why 
he does this and not that. He has a plan or scheme which he 
puts into execution. And if it fail, he is not content till 
he finds out wherein the failure lay. This enables him to plan 
a better scheme. He sees why it is better; and if at last he 
be successful by a happy hit, as in the chance procedure of 
intelligence, he looks for the reason of it. And seeing why 
this fortunate attempt, unlike his previous efforts, just meets 
the case, he repeats it because he perceives that herein lies the 
essential solution of the difficulty. Both in the case of intelli- 
gence and in that of reason, as here distinguished, present 
procedure is based upon past experience; but reason has built 
upon the foundations thus laid an orderly scheme, and knows 
its whys and wherefores, while intelligence is at the mercy of 
chance associations. The reason for success it has not the wit 
to assign. 
The essential difference between the two cases may be put 
in another way by saying that the intelligent being forms 
sensory impressions and sensory images linked together by 
