— 474 —
Chapter VIII

Of Abstract and Concrete Terms.

Abstract Terms not predicable one of another, and why.
      §1.The ordinary Words of Language, and our common use of
them, would have given us light into the nature of our Ideas, if they
had been but considered with attention. The Mind, as has been
shewn, has a power to abstract its Ideas, and so they become
Essences, general Essences, whereby the Sorts of Things are dis-
tinguished. Now each abstract Idea being distinct, so that of any
two the one can never be the other, the Mind will, by its intuitive
knowledge, perceive their difference; and therefore in Propositions,
no two whole Ideas can ever be affirmed one of another. This we see
in the common use of Language, which permits not any two abstract
Words, or Names of abstract Ideas, to be affirmed one of another. For how
near of kin soever they may seem to be, and how certain soever it is,
that Man is an Animal, or rational, or white, yet every one, at first
hearing, perceives the falshood of these Propositions; Humanity is
Animality, or Rationality, or Whiteness: And this is as evident, as any
of the most allow’d Maxims. All our Affirmations then are only in
concrete, which is the affirming, not one abstract Idea to be another,
but one abstract Idea to be join’d to another; which abstract Ideas,
in Substances, may be of any sort; in all the rest, are little else but of
Relations; and in Substances, the most frequent are of Powers; v.g.
a Man is White, signifies, that the thing that has the Essence of a
Man, has also in it the Essence of Whiteness, which is nothing but a
power to produce the Idea of Whiteness in one, whose Eyes can
discover ordinary Objects; or a Man is rational, signifies, that the
same thing, that hath the Essence of a Man, hath also in it the
Essence of Rationality, i.e. a power of Reasoning.
Locke Hum III, 8, §1, p. 474