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.
2. They show the difference of our ideas. This distinction of names shows us also the difference of
our ideas: for if we observe them, we shall find that our simple ideas have all abstract as well as
concrete names: the one whereof is (to speak the language of grammarians) a substantive, the
other an adjective; as whiteness, white; sweetness, sweet. The like also holds in our ideas of modes
and relations; as justice, just; equality, equal: only with this difference, that some of the concrete
names of relations amongst men chiefly are substantives; as, paternitas, pater; whereof it were easy
to render a reason. But as to our ideas of substances, we have very few or no abstract names at all.
For though the Schools have introduced animalitas, humanitas, corporietas, and some others; yet
they hold no proportion with that infinite number of names of substances, to which they never were
ridiculous enough to attempt the coining of abstract ones: and those few that the schools forged,
and put into the mouths of their scholars, could never yet get admittance into common use, or obtain
the license of public approbation. Which seems to me at least to intimate the confession of all
mankind, that they have no ideas of the real essences of substances, since they have not names for
such ideas: which no doubt they would have had, had not their consciousness to themselves of their
ignorance of them kept them from so idle an attempt. And therefore, though they had ideas enough
to distinguish gold from a stone, and metal from wood; yet they but timorously ventured on such
terms, as aurietas and saxietas, metallietas and lignietas, or the like names, which should pretend
to signify the real essences of those substances whereof they knew they had no ideas. And indeed
it was only the doctrine of substantial forms, and the confidence of mistaken pretenders to a
knowledge that they had not, which first coined and then introduced animalitas and humanitas, and
the like; which yet went very little further than their own Schools, and could never get to be current
amongst understanding men. Indeed, humanitas was a word in familiar use amongst the Romans;
but in a far different sense, and stood not for the abstract essence of any substance; but was the
abstracted name of a mode, and its concrete humanus, not homo.