An Essay Concerning Humane Understanding, Volume 2: MDCXC, Based on the 2nd Edition, Books 3 and 4
John Locke · en
of one and of two, the idea of yellow, and the idea of blue, he cannot
but certainly know that the idea of one is the idea of one, and not the
idea of two; and that the idea of yellow is the idea of yellow, and not
the idea of blue. For a man cannot confound the ideas in his mind, which
he has distinct: that would be to have them confused and distinct at the
same time, which is a contradiction: and to have none distinct, is
to have no use of our faculties, to have no knowledge at all. And,
therefore, what idea soever is affirmed of itself, or whatsoever two
entire distinct ideas are denied one of another, the mind cannot
but assent to such a proposition as infallibly true, as soon as it
understands the terms, without hesitation or need of proof, or regarding
those made in more general terms and called maxims.
11. What use these general Maxims or Axioms have.
[What shall we then say? Are these general maxims of no use? By no
means; though perhaps their use is not that which it is commonly taken
to be. But, since doubting in the least of what hath been by some
men ascribed to these maxims may be apt to be cried out against, as
overturning the foundations of all the sciences; it may be worth while
to consider them with respect to other parts of our knowledge, and
examine more particularly to what purposes they serve, and to what not.
{Of no use to prove less general propositions, nor as foundations on
consideration of which any science has been built.}
(1) It is evident from what has been already said, that they are of no
use to prove or confirm less general self-evident propositions. (2) It
is as plain that they are not, nor have been the foundations whereon
any science hath been built. There is, I know, a great deal of talk,
propagated from scholastic men, of sciences and the maxims on which
they are built: but it has been my ill-luck never to meet with any such
sciences; much less any one built upon these two maxims, WHAT IS, IS;
and IT IS IMPOSSIBLE FOR THE SAME THING TO BE AND NOT TO BE. And I would
be glad to be shown where any such science, erected upon these or any
other general axioms is to be found: and should be obliged to any one
who would lay before me the frame and system of any science so built on
these or any such like maxims, that could not be shown to stand as firm
without any consideration of them. I ask, Whether these general maxims
have not the same use in the study of divinity, and in theological
questions, that they have in other sciences? They serve here, too, to
silence wranglers, and put an end to dispute. But I think that nobody
will therefore say, that the Christian religion is built upon these
maxims, or that the knowledge we have of it is derived from these
principles. It is from revelation we have received it, and without
revelation these maxims had never been able to help us to it. When we
find out an idea by whose intervention we discover the connexion of two