9. No discoverable necessary connexion between nominal essence of gold and other simple ideas.
As there is no
discoverable connexion between fixedness and the colour, weight, and other simple ideas of that nominal essence
of gold; so, if we make our complex idea of gold, a body yellow, fusible, ductile, weighty, and fixed, we shall be
at the same uncertainty concerning solubility in aqua regia, and for the same reason. Since we can never, from
consideration of the ideas themselves, with certainty affirm or deny of a body whose complex idea is made up of
yellow, very weighty, ductile, fusible, and fixed, that it is soluble in aqua regia: and so on of the rest of its
qualities. I would gladly meet with one general affirmation concerning any quality of gold, that any one can
certainly know is true. It will, no doubt, be presently objected, Is not this an universal proposition, All gold is
malleable? To which I answer, It is a very certain proposition, if malleableness be a part of the complex idea the
word gold stands for. But then here is nothing affirmed of gold, but that that sound stands for an idea in which
malleableness is contained: and such a sort of truth and certainty as this it is, to say a centaur is four-footed. But if
malleableness make not a part of the specific essence the name of gold stands for, it is plain, all gold is malleable,
is not a certain proposition. Because, let the complex idea of gold be made up of whichsoever of its other qualities
you please, malleableness will not appear to depend on that complex idea, nor follow from any simple one
contained in it: the connexion that malleableness has (if it has any) with those other qualities being only by the
intervention of the real constitution of its insensible parts; which, since we know not, it is impossible we should
perceive that connexion, unless we could discover that which ties them together.
