ABSTRACT
Our discussions, hitherto, have been concerned very largely with Man, but Man on his own account is not the true subject-matter of philosophy. What concerns philosophy is the universe as a whole; Man demands consideration solely as the instrument by means of which we acquire knowledge of the universe. And that is why it is human beings as capable of knowledge that have concerned us mainly in past chapters, rather than as centres of will or of emotion. We are not in the mood proper to philosophy so long as we are interested in the world only as it affects human beings; the philosophic spirit demands an interest in the world for its own sake. But since we apprehend the world through our own senses, and think about it with our own intellect, the picture that we acquire is inevitably coloured by the personal medium through which it comes to us. Consequently we have to study this medium, namely ourselves, in order to find out, if we can, what elements in our picture of the world are contributed by us, and what elements we may accept as
representative of outside fact. Previous chapters have studied cognition, both as an outwardly observable reaction, and as it appears to introspection. In the chapters that remain, we shall be concerned with what we can know about the universe, in view of the nature of the instrument that we have to employ. I do not think we can know as much as many philosophers of the past have supposed, but I think it is worth while to have in our minds an outline of their systems. I shall therefore begin by setting forth a few typical philosophical constructions of earlier centuries.
