in
this way of speaking, nothing is gold but what partakes of an essence,
which we, not knowing, cannot know where it is or is not, and so cannot
be sure that any parcel of matter in the world is or is not in this
sense gold; being incurably ignorant whether IT has of has not that
which makes anything to be called gold; i. e. that real essence of gold
whereof we have no idea at all. This being as impossible for us to know
as it is for a blind man to tell in what flower the colour of a pansy is
or is not to be found, whilst he has no idea of the colour of a pansy at
all. Or if we could (which is impossible) certainly know where a real
essence, which we know not, is, v.g. in what parcels of matter the real
essence of gold is, yet could we not be sure that this or that quality
could with truth be affirmed of gold; since it is impossible for us to
know that this or that quality or idea has a necessary connexion with
a real essence of which we have no idea at all, whatever species that
supposed real essence may be imagined to constitute.]

6.

On the other side, the names of substances, when made use of as they
should be, for the ideas men have in their minds, though they carry a
clear and determinate signification with them, will not yet serve us to
make many universal propositions of whose truth we can be certain. Not
because in this use of them we are uncertain what things are signified
by them, but because the complex ideas they stand for are such
combinations of simple ones as carry not with them any discoverable
connexion or repugnancy, but with a very few other ideas.

7.

The complex ideas that our names of the species of substances properly
stand for, are collections of such qualities as have been observed to
co-exist in an unknown substratum, which we call substance; but what
other qualities necessarily co-exist with such combinations, we cannot
certainly know, unless we can discover their natural dependence; which,
in their primary qualities, we can go but a very little way in; and in
all their secondary qualities we can discover no connexion at all: for
the reasons mentioned, chap. iii. Viz. 1. Because we know not the
real constitutions of substances, on which each secondary quality
particularly depends. 2. Did we know that, it would serve us only for
experimental (not universal) knowledge; and reach with certainty no
further than that bare instance: because our understandings can
discover no conceivable