— 470 —
Which supposition is of no use.       §50. For let us consider, when we affirm, that all Gold is fixed,
either it means that Fixedness is a part of the Definition, part of the
nominal Essence the Word Gold stands for; and so this Affirmation,
all Gold is fixed, contains nothing but the signification of the Term
Gold. Or else it means, that Fixedness not being a part of the
definition of the Word Gold, is a Property of that Substance it self:
in which case, it is plain, that the Word Gold stands in the place of a
Substance, having the real Essence of a Species of Things, made by
Nature. In which way of Substitution, it has so confused and un-
certain a signification, that though this Proposition, Gold is fixed, be
in that sense an Affirmation of something real; yet ’tis a Truth will
always fail us in its particular Application, and so is of no real Use
nor Certainty. For let it be never so true, that all Gold, i.e. all that
has the real Essence of Gold, is fixed, What serves this for, whilst we
know not in this sense, what is or is not Gold? For if we know not
the real Essence of Gold, ’tis impossible we should know what
parcel of Matter has that Essence, and so whether it be true Gold
or no.
Locke Hum III, 6, §50, p. 470