174 % Animal Intelligence 
dinner. The outside world also is to them in large part a 
multitude of definite percepts. They feel the environment | 
as trees, sticks, stones, chairs, tables, letters, words, etc.) 
I have called such definite presentations ‘free ideas’ to 
distinguish them from the vague presentations such as 
atmospheric pressure, the feeling of malaise, of the position 
of one’s body when falling, etc. It is such ‘free ideas’ 
which compose the substance of thought and which 
lead us to perhaps the majority of the different acts we 
perform, though we do, of course, react to the vaguer sort 
as well. I saw definitely in writing the last sentence the 
words ‘majority of the different acts’ and thought ‘we 
perform’ and so wrote it. \I see a bill and so take check 
book and pen and write. I think of the cold outside and 
so put on an overcoat. “This mental function ‘having free 
ideas,’ gives the possibility of learning to meet situations 
properly by thinking about them, by being reminded of 
some property of the fact before us or some element therein. 
We can divide all learning into learning by trial and 
accidental success, by the strengthériing of the connections 
between the sense-impressions representing the situation 
and the acts——or impulses and acts— representing our 
successful response to it and by the inhibition of similar 
connections with unsuccessful responses; }(2) learning by 
imitation, where the mere performance by another of a 
certain act in a certain situation leads us to do the same; 
and’ (3)\Jearning by ideas, where the situation calls up some 
idea (or ideas) which then arouses the act or in some way 
modifies it. 
. The last method of learning has obviously been the means 
of practically all the advances in civilization. The evidence 
quoted a paragraph or so back from the Experimental 
Study shows the typical mammalian mind to be one which 
