a mere "we know not what," whose function it is to
hold together the bundles of qualities that constitute the things we
know.

In the modern philosophy men still distinguish between substance and
qualities. It is a useful distinction, and we could scarcely get on
without it. But an increasing number of thoughtful persons repudiate
the old notion of substance altogether.

We may, they say, understand by the word "substance" the whole group of
qualities _as a group_--not merely the qualities that are revealed at a
given time, but all those that we have reason to believe a fuller
knowledge would reveal. In short, we may understand by it just what is
left when the "we know not what" of the Lockian has been discarded.

This notion of substance we may call the more modern one; yet we can
hardly say that it is the notion of the plain man. He does not make
very clear to himself just what is in his thought, but I think we do
him no injustice in maintaining that he is something of a Lockian, even
if he has never heard of Locke. The Lockian substance is, as the
reader has seen, a sort of "unknowable."

And now for the doctrine that the mind is nonextended and immaterial.
With these affirmations we may heartily agree; but we must admit that
the plain man enunciates them without having a very definite idea of
what the mind is.

He regards as in his mind all his sensations and ideas, all his
perceptions and mental images of things. Now, suppose I close my eyes
and picture to myself a barber's pole. Where is the image? We say, in
the mind. Is it extended? We feel impelled to answer, No. But it
certainly _seems_ to be extended; the white and the red upon it appear
undeniably side by side. May I assert that this mental image has no
extension whatever? Must I deny to it _parts_, or assert that its
parts are not side by side?

It seems odd to maintain that a something as devoid of parts as is a
mathematical point should yet appear to have parts and to be extended.
On the other hand, if we allow the image to be extended, how can we
refer it to a nonextended mind?

To such questions as these, I do not think that the plain man has an
answer. That they can be answered, I shall try to show in the last
section of this chapter. But one cannot answer them until one has
attained to rather a clear conception of what is meant by the mind.

And until one has attained to such a conception, the statement that the
mind is immat