12. Abstract ideas are the essences of genera and species.
The next thing therefore to be considered is, What kind
of signification it is that general words have. For, as it is evident that they do not signify barely one particular
thing; for then they would not be general terms, but proper names, so, on the other side, it is as evident they do not
signify a plurality; for man and men would then signify the same; and the distinction of numbers (as the
grammarians call them) would be superfluous and useless. That then which general words signify is a sort of
things; and each of them does that, by being a sign of an abstract idea in the mind; to which idea, as things
existing are found to agree, so they come to be ranked under that name, or, which is all one, be of that sort.
Whereby it is evident that the essences of the sorts, or, if the Latin word pleases better, species of things, are
nothing else but these abstract ideas. For the having the essence of any species, being that which makes anything
to be of that species; and the conformity to the idea to which the name is annexed being that which gives a right to
that name; the having the essence, and the having that conformity, must needs be the same thing: since to be of
any species, and to have a right to the name of that species, is all one. As, for example, to be a man, or of the
species man, and to have right to the name man, is the same thing. Again, to be a man, or of the species man, and
have the essence of a man, is the same thing. Now, since nothing can be a man, or have a right to the name man,
but what has a conformity to the abstract idea the name man stands for, nor anything be a man, or have a right to
the species man, but what has the essence of that species; it follows, that the abstract idea for which the name
stands, and the essence of the species, is one and the same. From whence it is easy to observe, that the essences of
the sorts of things, and, consequently, the sorting of things, is the workmanship of the understanding that abstracts
and makes those general ideas.
