CAUSES OF SCIENTIFIC KNOWLEDGE 269

It is indeed a persuasion of many men of science that all

the characteristics, all the sense-organs, and all the intelli-

gence which any animal possesses, are and must have been

due to "Natural Selection," that is, to the preservation in

the struggle for life of the creatures possessing such sense-

organs and intelligence. Why then,* it is asked, may not

human reason be in the same case? Why may it not be

the mere result of a fortunate psychical variation which has

enabled the primitive brutal man to destroy and feed on

the brutal animal a trifle more easily than before? Is it

possible for us to trust and confide in a faculty which has

been attained slowly through the persistent endeavours of

our semi-simian forefathers to feed and breed? A faculty

so developed may be admirable as a weapon, but what

guarantee have we to regard it as suited for very different

purposes, namely, to reveal to us the true nature of the world

in which we find ourselves, and to show us what it is

reasonable for us to do in other directions?

This objection we have long before referred to,* stating

that it would be more fully considered later on. For such

fuller consideration the time has now come.

But we may here remind our readers of what we before

pointed outf If our conviction about the existence of an ex-

ternal world had been produced by " Natural Selection," that

would constitute a triumphant argument against Idealism.

For, unless an independent, extended, and external world

really existed, no sentient organisms would be destroyed by

contravening the laws and conditions thereof. If it had acted

so efficiently, it must have been a reality. But, though there

has been, and still is, a great deal of talking and writing

about " Natural Selection," it is surprising how many persons

talk and write about it without knowing what it really is.

It may be useful, therefore, to say here a few words upon

* See Chapter III., p. 56. t See ante, p. 48.

It is indeed a persuasion of many men of science that all

the characteristics, all the sense-organs, and all the intelli-

gence which any animal possesses, are and must have been

due to "Natural Selection," that is, to the preservation in

the struggle for life of the creatures possessing such sense-

organs and intelligence. Why then,* it is asked, may not

human reason be in the same case? Why may it not be

the mere result of a fortunate psychical variation which has

enabled the primitive brutal man to destroy and feed on

the brutal animal a trifle more easily than before? Is it

possible for us to trust and confide in a faculty which has

been attained slowly through the persistent endeavours of

our semi-simian forefathers to feed and breed? A faculty

so developed may be admirable as a weapon, but what

guarantee have we to regard it as suited for very different

purposes, namely, to reveal to us the true nature of the world

in which we find ourselves, and to show us what it is

reasonable for us to do in other directions?

This objection we have long before referred to,* stating

that it would be more fully considered later on. For such

fuller consideration the time has now come.

But we may here remind our readers of what we before

pointed outf If our conviction about the existence of an ex-

ternal world had been produced by " Natural Selection," that

would constitute a triumphant argument against Idealism.

For, unless an independent, extended, and external world

really existed, no sentient organisms would be destroyed by

contravening the laws and conditions thereof. If it had acted

so efficiently, it must have been a reality. But, though there

has been, and still is, a great deal of talking and writing

about " Natural Selection," it is surprising how many persons

talk and write about it without knowing what it really is.

It may be useful, therefore, to say here a few words upon

* See Chapter III., p. 56. t See ante, p. 48.