science. Idealists, materialists, and ordinary mortals have been
in agreement on one point: that they knew sufficiently what they
meant by the words "mind" and "matter" to be able to conduct
their debate intelligently. Yet it was just in this point, as to
which they were at one, that they seem to me to have been all
alike in error.

The stuff of which the world of our experience is composed is, in
my belief, neither mind nor matter, but something more primitive
than either. Both mind and matter seem to be composite, and the
stuff of which they are compounded lies in a sense between the
two, in a sense above them both, like a common ancestor. As
regards matter, I have set forth my reasons for this view on
former occasions,* and I shall not now repeat them. But the
question of mind is more difficult, and it is this question that
I propose to discuss in these lectures. A great deal of what I
shall have to say is not original; indeed, much recent work, in
various fields, has tended to show the necessity of such theories
as those which I shall be advocating. Accordingly in this first
lecture I shall try to give a brief description of the systems of
ideas within which our investigation is to be carried on.

* "Our Knowledge of the External World" (Allen & Unwin), Chapters
III and IV. Also "Mysticism and Logic," Essays VII and VIII.


If there is one thing that may be said, in the popular
estimation, to characterize mind, that one thing is
"consciousness." We say that we are "conscious" of what we see
and hear, of what we remember, and of our own thoughts and