77. THAT A SUBSTRATUM NOT PERCEIVED, MAY EXIST, UNIMPORTANT.--But,
say you, though it be granted that there is no thoughtless support
of extension and the other qualities or accidents which we perceive,
yet there may perhaps be some inert, unperceiving substance or
substratum of some other qualities, as incomprehensible to us as colours
are to a man born blind, because we have not a sense adapted to them.
But, if we had a new sense, we should possibly no more doubt of their
existence than a blind man made to see does of the existence of light and
colours. I answer, first, if what you mean by the word Matter be only the
unknown support of unknown qualities, it is no matter whether there is
such a thing or no, since it no way concerns us; and I do not see the
advantage there is in disputing about what we know not what, and we know
not why.

78. But, secondly, if we had a new sense it could only furnish us with
new ideas or sensations; and then we should have the same reason against
their existing in an unperceiving substance that has been already offered
with relation to figure, motion, colour and the like. Qualities, as has
been shown, are nothing else but sensations or ideas, which exist only in
a mind perceiving them; and this is true not only of the ideas we are
acquainted with at present, but likewise of all possible ideas
whatsoever.

79. But, you will insist, what if I have no reason to believe the
existence of Matter? what if I cannot assign any use to it or explain
anything by it, or even conceive what is meant by that word? yet still it
is no contradiction to say that Matter exists, and that this Matter is in
general a substance, or occasion of ideas; though indeed to go about to
unfold the meaning or adhere to any particular explication of those words
may be attended with great difficulties. I answer, when words are used