An Essay Concerning Humane Understanding, Volume 2: MDCXC, Based on the 2nd Edition, Books 3 and 4
John Locke · en
of CHURCH and FAITH, of POWER and RIGHT, of OBSTRUCTIONS and HUMOURS,
MELANCHOLY and CHOLER, would perhaps have little left in their thoughts
and meditations, if one should desire them to think only of the things
themselves, and lay by those words with which they so often confound
others, and not seldom themselves also.
5. Mental and Verbal Propositions contrasted.
But to return to the consideration of truth: we must, I say, observe two
sorts of propositions that we are capable of making:--
First, MENTAL, wherein the ideas in our understandings are without the
use of words put together, or separated, by the mind perceiving or
judging of their agreement or disagreement.
Secondly, VERBAL propositions, which are words, the signs of our ideas,
put together or separated in affirmative or negative sentences. By which
way of affirming or denying, these signs, made by sounds, are, as it
were, put together or separated from another. So that proposition
consists in joining or separating signs; and truth consists in the
putting together or separating those signs, according as the things
which they stand for agree or disagree.
6. When Mental Propositions contain real Truth, and when Verbal.
Every one's experience will satisfy him, that the mind, either by
perceiving, or supposing, the agreement or disagreement of any of its
ideas, does tacitly within itself put them into a kind of proposition
affirmative or negative; which I have endeavoured to express by the
terms putting together and separating. But this action of the mind,
which is so familiar to every thinking and reasoning man, is easier to
be conceived by reflecting on what passes in us when we affirm or deny,
than to be explained by words. When a man has in his head the idea of
two lines, viz. the side and diagonal of a square, whereof the diagonal
is an inch long, he may have the idea also of the division of that line
into a certain number of equal parts; v.g. into five, ten, a hundred, a
thousand, or any other number, and may have the idea of that inch line
being divisible, or not divisible, into such equal parts, as a certain
number of them will be equal to the sideline. Now, whenever he
perceives, believes, or supposes such a kind of divisibility to agree or
disagree to his idea of that line, he, as it were, joins or separates
those two ideas, viz. the idea of that line, and the idea of that kind
of divisibility; and so makes a mental proposition, which is true or
false, according as such a kind of divisibility, a divisibility into
such ALIQUOT parts, does really agree to that line or no. When ideas are
so put together, or separated in the mind, as they or the things they
stand for do agree or not, that is, as I may call it, MENTAL TRUTH. But
TRUTH OF WORDS is something more; and that is the affirming or denying
of words one of another, as the ideas they stand for agree or disagree:
and this again is two-fold; either purely verbal and trifling, which I
shall speak of, (chap.