— 449 —
Our nominal Essences of Substances, not perfect Collections of Properties.       §19. Fifthly, The only imaginable help in this case would be, that
having framed perfect complex Ideas of the Properties of things,
flowing from their different real Essences, we should thereby
distinguish them into Species. But neither can this be done: for being
ignorant of the real Essence it self, it is impossible to know all those
Properties, that flow from it, and are so annexed to it, that any one
of them being away, we may certainly conclude, that that Essence
is not there, and so the Thing is not of that Species. We can never
know what are the precise number of Properties depending on the
real Essence of Gold, any one of which failing, the real Essence of
Gold, and consequently Gold, would not be there, unless we knew
the real Essence of Gold it self, and by that determined that Species.
By the Word Gold here, I must be understood to design a particular
piece of Matter; v.g. the last Guinea that was coin’d. For if it should
stand here in its ordinary Signification for that complex Idea,
which I, or any one else calls Gold; i.e. for the nominal Essence of
Gold, it would be Jargon: so hard is it, to shew the various meaning
and imperfection of Words, when we have nothing else but Words
to do it by.
Locke Hum III, 6, §19, p. 449