50. Which supposition is of no use.
For, let us consider, when we affirm that "all gold is fixed," either it means
that fixedness is a part of the definition, i.e.,, 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 gold, is a property of that substance itself: 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 uncertain a signification, that, though this
proposition--"gold is fixed"--be in that sense an affirmation of something real; yet it is a truth will always fail us
in its particular application, and so is of no real use or certainty. For let it be ever 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, it is impossible we should know what parcel of matter has that
essence, and so whether it be true gold or no.