PREFACE ix

Obviously, without an adequate acquaintance with the

nature of our ideas no one can hope to succeed in a task

an important part of which consists in the analysis of mental

conceptions. What factors, therefore, co-operate in their

elicitation, and the nature of such factors, the shares they

respectively take and the rank of each in ideation, are

preliminary matters which must be noted at the very com-

mencement of this book. Similarly, no one can arrive at

even a provisional conclusion with respect to any merely

initial problem unless he can be satisfied that there is some

criterion of truth and that he can avail himself of it. To

these first steps towards an understanding of the groundwork

of science, the earlier portion of this book must, it appears

to us, be exclusively devoted.

But in order to explore the groundwork of all science, it

seems reasonable that the reader's attention should also be

called to the different kinds of systematic and organized

inquiry the different sciences about which men's minds

have been hitherto occupied their number, nature, and the

various degrees of affinity and relationship existing between

them, etc. But before we can take another step forwards we

shall find our progress arrested by the Idealists It is true

that we hear it said that all the physical sciences can be

pursued and taught as well on the Idealistic hypothesis as

on that view concerning a real, external, independent world

existing on all sides, which is entertained by all men who are

not Idealists. This we regard as true for one reason only;

the reason, namely, that nature is too strong for Idealism,

and that no man can be always a consistent Idealist, least

of all students and adepts in physical science, who are con-

tinually recognizing in thought and speech, and are constantly

occupied about certain bodies acting and interacting upon

other bodies, not only quite without regard to their own

perceptions (which need not be adverted to as being such),

A 2

Obviously, without an adequate acquaintance with the

nature of our ideas no one can hope to succeed in a task

an important part of which consists in the analysis of mental

conceptions. What factors, therefore, co-operate in their

elicitation, and the nature of such factors, the shares they

respectively take and the rank of each in ideation, are

preliminary matters which must be noted at the very com-

mencement of this book. Similarly, no one can arrive at

even a provisional conclusion with respect to any merely

initial problem unless he can be satisfied that there is some

criterion of truth and that he can avail himself of it. To

these first steps towards an understanding of the groundwork

of science, the earlier portion of this book must, it appears

to us, be exclusively devoted.

But in order to explore the groundwork of all science, it

seems reasonable that the reader's attention should also be

called to the different kinds of systematic and organized

inquiry the different sciences about which men's minds

have been hitherto occupied their number, nature, and the

various degrees of affinity and relationship existing between

them, etc. But before we can take another step forwards we

shall find our progress arrested by the Idealists It is true

that we hear it said that all the physical sciences can be

pursued and taught as well on the Idealistic hypothesis as

on that view concerning a real, external, independent world

existing on all sides, which is entertained by all men who are

not Idealists. This we regard as true for one reason only;

the reason, namely, that nature is too strong for Idealism,

and that no man can be always a consistent Idealist, least

of all students and adepts in physical science, who are con-

tinually recognizing in thought and speech, and are constantly

occupied about certain bodies acting and interacting upon

other bodies, not only quite without regard to their own

perceptions (which need not be adverted to as being such),

A 2