see or feel what matter is like apart from the 'I' which knows {8} it.
He may, indeed, infer that this matter exists apart from the 'I' which
knows it. He may infer that it exists, and may even go as far as to
assume that, apart from his seeing or touching, or anybody else's
seeing or touching, matter possesses all those qualities which it
possesses for his own consciousness. But this is inference, and not
immediate knowledge. And the validity or reasonableness of the
inference may be disputed. How far it is reasonable or legitimate to
attribute to matter as it is in itself the qualities which it has for
us must depend upon the nature of those qualities. Let us then go on
to ask whether the qualities which constitute matter as we know it are
qualities which we can reasonably or even intelligibly attribute to a
supposed matter-in-itself, to matter considered as something capable of
existing by itself altogether apart from any kind of conscious
experience.

In matter, as we know it, there are two elements. There are certain
sensations, or certain qualities which we come to know by sensation,
and there are certain relations. Now, with regard to the sensations, a
very little reflection will, I think, show us that it is absolutely
meaningless to say that matter has the qualities implied by these
sensations, even when they are not felt, and would still possess them,
even supposing it never had been and never would be felt by any one
whatever. In a world in which {9} there were no eyes and no minds,
what would be the meaning of saying that things were red or blue? In a
world in which there were no ears and no minds, there would clearly be
no such thing as sound. This is exactly the point at which Locke's
analysis stopped. He admitted that the 'secondary qualities'--colours,
sounds, tastes--of objects were really not in the things themselves but
in the mind which perceives them. What existed in the things was
merely a power of producing these sensations in us, the quality in the
thing being not in the least like the sensations which it produces in
us: he admitted that this power of producing a sensation was something
different from, and totally unlike, the sensation itself. But when he
came to the primary qualities--solidity, shape, magnitude and the
like--he supposed that the qualities in the thing were exactly the same
as they are for our minds. If all mind were to disappear from the
Universe, there would hencef