PREFACE xvii

bring to a conclusion all but the main question to be dealt

with.

When, in our final chapter, we have to apply ourselves

directly to that main question, in the light derived from

the various preceding investigations, the groundwork of

science will, we are persuaded, be found to consist of three

divisions : the labourers who work, the tools they must

employ, and that which constitutes the field of their labour.

Taking the last first, it will, we think, appear that the

matter of science is partly physical and partly psychical.

In relation with the former, questions concerning the various

physical energies, matter, motion, space, and time must be

noted, and an inquiry made as to the value of a mechanical

theory of the universe, and the reasons why it is so commonly

acceptable. Next must come some reference to the tools

which must be made use of, namely, those first principles

and universal, necessary, self-evident truths which lie, so

frequently unnoticed, within the human intellect, and which

are absolutely indispensable for valid reasoning. Finally,

the nature of the workers themselves must also be noticed,

as necessarily affecting the value of their work ; and, last of

all, a few words must be devoted to the question whether

there is any, and, if any, what, foundation underlying the

whole groundwork of science, and giving support and validity

to that entire conception of the universe which an impartial

study of the phenomena it exhibits may have led us to

regard as alone consonant with the dictates of reason.

bring to a conclusion all but the main question to be dealt

with.

When, in our final chapter, we have to apply ourselves

directly to that main question, in the light derived from

the various preceding investigations, the groundwork of

science will, we are persuaded, be found to consist of three

divisions : the labourers who work, the tools they must

employ, and that which constitutes the field of their labour.

Taking the last first, it will, we think, appear that the

matter of science is partly physical and partly psychical.

In relation with the former, questions concerning the various

physical energies, matter, motion, space, and time must be

noted, and an inquiry made as to the value of a mechanical

theory of the universe, and the reasons why it is so commonly

acceptable. Next must come some reference to the tools

which must be made use of, namely, those first principles

and universal, necessary, self-evident truths which lie, so

frequently unnoticed, within the human intellect, and which

are absolutely indispensable for valid reasoning. Finally,

the nature of the workers themselves must also be noticed,

as necessarily affecting the value of their work ; and, last of

all, a few words must be devoted to the question whether

there is any, and, if any, what, foundation underlying the

whole groundwork of science, and giving support and validity

to that entire conception of the universe which an impartial

study of the phenomena it exhibits may have led us to

regard as alone consonant with the dictates of reason.