1. Abstract terms not predictable one of another, and why.
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 shown, has a power to abstract its ideas, and so they become essences, general essences,
whereby the sorts of things are distinguished. 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 falsehood of these propositions: humanity is animality, or rationality, or
whiteness: and this is as evident as any of the most allowed 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 joined 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.