ct idea, which
is looked upon as the essence and standard of a species? All such
patterns and standards being quite laid aside, particular beings,
considered barely in themselves, will be found to have all their
qualities equally essential; and everything in each individual will be
essential to it; or, which is more, nothing at all. For, though it may
be reasonable to ask, Whether obeying the magnet be essential to iron?
yet I think it is very improper and insignificant to ask, whether it be
essential to the particular parcel of matter I cut my pen with; without
considering it under the name IRON, or as being of a certain species.
And if, as has been said, our abstract ideas, which have names annexed
to them, are the boundaries of species, nothing can be essential but
what is contained in those ideas.

6. Even the real essences of individual substances imply potential
sorts.

It is true, I have often mentioned a REAL ESSENCE, distinct in
substances from those abstract ideas of them, which I call their
nominal essence. By this real essence I mean, that real constitution
of anything, which is the foundation of all those properties that are
combined in, and are constantly found to co-exist with the nominal
essence; that particular constitution which everything has within
itself, without any relation to anything without it. But essence, even
in this sense, RELATES TO A SORT, AND SUPPOSES A SPECIES. For, being
that real constitution on which the properties depend, it necessarily
supposes a sort of things, properties belonging only to species, and not
to individuals: v. g. supposing the nominal essence of gold to be a body
of such a peculiar colour and weight, with malleability and fusibility,
the real essence is that constitution of the parts of matter on which
these qualities and their union depend; and is also the foundation of
its solubility in aqua regia and other properties, accompanying that
complex idea. Here are essences and properties, but all upon supposition
of a sort or general abstract idea, which is considered as immutable;
but there is no individual parcel of matter to which any of these
qualities are so annexed as to be essential to it or inseparable from
it. That which is essential belongs to it as a condition whereby it
is of this or that sort: but take away the consideration of its being
ranked under the name of some abstract idea, and then there is nothing
necessary to it, nothing inseparable from it.