PREFACE xiii

and, if so, what are its utmost powers and capabilities.

Very special attention also needs to be given to the con-

sideration of the phenomena of instinct.

But as Idealists appear to bar the way to what, for all but

themselves, can alone lead to a satisfactory epistemology, so

a distinguished school of naturalists oppose an analogous,

though very different, obstacle to our even entertaining a

reasonable hope that we may be able to see and comprehend

what are and must be the foundations of science.

\Yhat confidence, it has been asked, can we place in the

declaration of an ape's mind ? Now we by no means admit

that were the human intellect and the highest powers of

brutes really of one kind (so that the essential rationality of

animals was simply restrained by circumstances from making

itself manifest), any valid ground for distrusting truths,

which to us are self-evident, would thence arise. On the

contrary, instead of giving us good reasons for such distrust,

it would but supply us with an amply sufficient motive for

an enormously increased regard for what we might certainly

then, with reason, call our "poor relations." What seems

to us to be clear and indisputably evident in and by itself,

and what reason demonstrates absolutely, can be none the

less true on account of its cause and origin, or the mode

in which it may have become manifest. It is plain that in

our own case the truths which are for us most certain, must

have been gained through the evolution and development of

psychical power latent in the mind of an unconscious infant,

which once showed no sign whatever of rationality. Why

then should we distrust the dictates of a mind evolved from

creatures which, though giving no evidence of actual ration-

ality, afford us far more signs of cognitive energy than does

the child for some time after its birth ?

Nevertheless, since there are so many persons who do feel

a sceptical distrust of their reason on account of the source

and, if so, what are its utmost powers and capabilities.

Very special attention also needs to be given to the con-

sideration of the phenomena of instinct.

But as Idealists appear to bar the way to what, for all but

themselves, can alone lead to a satisfactory epistemology, so

a distinguished school of naturalists oppose an analogous,

though very different, obstacle to our even entertaining a

reasonable hope that we may be able to see and comprehend

what are and must be the foundations of science.

\Yhat confidence, it has been asked, can we place in the

declaration of an ape's mind ? Now we by no means admit

that were the human intellect and the highest powers of

brutes really of one kind (so that the essential rationality of

animals was simply restrained by circumstances from making

itself manifest), any valid ground for distrusting truths,

which to us are self-evident, would thence arise. On the

contrary, instead of giving us good reasons for such distrust,

it would but supply us with an amply sufficient motive for

an enormously increased regard for what we might certainly

then, with reason, call our "poor relations." What seems

to us to be clear and indisputably evident in and by itself,

and what reason demonstrates absolutely, can be none the

less true on account of its cause and origin, or the mode

in which it may have become manifest. It is plain that in

our own case the truths which are for us most certain, must

have been gained through the evolution and development of

psychical power latent in the mind of an unconscious infant,

which once showed no sign whatever of rationality. Why

then should we distrust the dictates of a mind evolved from

creatures which, though giving no evidence of actual ration-

ality, afford us far more signs of cognitive energy than does

the child for some time after its birth ?

Nevertheless, since there are so many persons who do feel

a sceptical distrust of their reason on account of the source