well as other general terms, stand
for SORTS: which is nothing else but the being made signs of such
complex ideas wherein several particular substances do or might agree,
by virtue of which they are capable of being comprehended in one common
conception, and signified by one name. I say do or might agree: for
though there be but one sun existing in the world, yet the idea of it
being abstracted, so that more substances (if there were several) might
each agree in it, it is as much a sort as if there were as many suns as
there are stars. They want not their reasons who think there are, and
that each fixed star would answer the idea the name sun stands for, to
one who was placed in a due distance: which, by the way, may show us how
much the sorts, or, if you please, GENERA and SPECIES of things (for
those Latin terms signify to me no more than the English word sort)
depend on such collections of ideas as men have made, and not on the
real nature of things; since it is not impossible but that, in propriety
of speech, that might be a sun to one which is a star to another.

2. The Essence of each Sort of substance is our abstract Idea to which
the name is annexed.

The measure and boundary of each sort or species, whereby it is
constituted that particular sort, and distinguished from others, is that
we call its ESSENCE, which is nothing but that abstract idea to which
the name is annexed; so that everything contained in that idea is
essential to that sort. This, though it be all the essence of natural
substances that WE know, or by which we distinguish them into sorts, yet
I call it by a peculiar name, the NOMINAL ESSENCE, to distinguish it
from the real constitution of substances, upon which depends this
nominal essence, and all the properties of that sort; which, therefore,
as has been said, may be called the REAL ESSENCE: v.g. the nominal
essence of gold is that complex idea the word gold stands for, let
it be, for instance, a body yellow, of a certain weight, malleable,
fusible, and fixed. But the real essence is the constitution of the
insensible parts of that body, on which those qualities and all the
other properties of gold depend. How far these two are different, though
they are both called essence, is obvious at first sight to discover.

3. The nominal and real Essence different.

For, though perhaps voluntary motion, with sense and reason, joined to a
body of a certain shape, be the complex idea to which I