12. Maxims, if care he not taken in the use of words, may prove contradictions.
One thing further, I think, it may
not be amiss to observe concerning these general maxims, That they are so far from improving or establishing our
minds in true knowledge, that if our notions be wrong, loose, or unsteady, and we resign up our thoughts to the
sound of words, rather than fix them on settled, determined ideas of things; I say these general maxims will serve
to confirm us in mistakes; and in such a way of use of words, which is most common, will serve to prove
contradictions: v.g. he that with Descartes shall frame in his mind an idea of what he calls body to be nothing but
extension, may easily demonstrate that there is no vacuum, i.e., no space void of body, by this maxim, What is, is.
For the idea to which he annexes the name body, being bare extension, his knowledge that space cannot be
without body, is certain. For he knows his own idea of extension clearly and distinctly, and knows that it is what it
is, and not another idea, though it be called by these three names,--extension, body, space. Which three words,
standing for one and the same idea, may, no doubt, with the same evidence and certainty be affirmed one of
another, as each of itself: and it is as certain, that, whilst I use them all to stand for one and the same idea, this
predication is as true and identical in its signification, that "space is body," as this predication is true and identical,
that "body is body," both in signification and sound.
