The Mental Life of the Monkeys 189 
the question an importance commensurate with the part 
it has played historically in animal psychology. |For I 
think it can be shown, and I hope in a later monograph 
to show, that reasoning is probably but one secondary 
result of the general function of having free ideas in great 
numbers, one product of a type of brain which works in 
great detail, not in gross associations. ] |The denial of reason- 
ing need not mean, and does not to my mind, any denial 
of continuity between animal and human mentality or any 
denial that the monkeys are mentally nearer relatives to 
man than are the other mammals. 
So much for supererogatory explanation. Let us now 
turn to a more definite and fruitful treatment of these 
records. 
{ihe difference between these records and those of the 
chitks, cats and dogs given on pages 39-65 passim is un- 
deniable. Whereas the latter were practically unani- 
mous, save in the cases_of the very easiest performances, 
in showing a process of gradual learning by a gradual 
elimination of unsuccessful movements, and a gradual 
reénforcement of the successful one, these are unanimous, 
save in the very hardest, in showing a process of sudden 
abandonment of the eedec oat movements and a selection 
of the appropriate one which rivals in suddenness the 
selections made by human beings in similar performances. 
It is natural to infer that the monkeys who suddenly re- 
place much general pulling and clawing by a single definite 
pull at a hook or bar have an idea of the hook or bar and 
of the movement they make. The rate of their progress 
is so different from that of the cats and dogs that we cannot 
help imagining as the cause of it a totally different mental 
function, namely, free ideas instead of vague sense-impres- 
