— 390 —
Thirdly, Ideas of Substances when false.       §18. Thirdly, Our complex Ideas of Substances, being all referred to
Patterns in Things themselves, may be false. That they are all false, when
looked upon as the Representations of the unknown Essences of
Things, is so evident, that there needs nothing to be said of it. I
shall therefore pass over that chimerical Supposition, and consider
them as Collections of simple Ideas in the Mind, taken from Com-
— 391 —
binations of simple Ideas existing together constantly in Things, of
which Patterns, they are the supposed Copies: And in this reference
of them, to the existence of Things, they are false Ideas. 1. When
they put together simple Ideas, which in the real Existence of
Things, have no union: as when to the Shape, and Size, that exist
together in a Horse, is joined, in the same complex Idea, the power
of Barking like a Dog: Which three Ideas, however put together into
one in the Mind, were never united in Nature: and this therefore
may be called a false Idea of an Horse. 2. Ideas of Substances are, in
this respect, also false, when from any Collection of simple Ideas,
that do always exist together, there is separated, by a direct
Negation, any other simple Idea, which is constantly joined with
them. Thus if to Extension, Solidity, Fusibility, the peculiar
Weightiness, and yellow Colour of Gold, any one join in his
Thoughts the Negation of a greater degree of fixedness, than is in
Lead or Copper, he may be said to have a false complex Idea, as well
as when he joins to those other simple ones, the Idea of perfect
absolute Fixedness. For either way, the complex Idea of Gold being
made up of such simple ones, as have no union in Nature, may be
termed false. But if he leave out of this his complex Idea, that of
Fixedness quite, without either actually joining to, or separating of
it from the rest in his Mind, it is, I think, to be looked on, as an
inadequate and imperfect Idea, rather than a false one: since though
it contains not all the simple Ideas, that are united in Nature, yet it
puts none together, but what do really exist together.
Locke Hum II, 32, §18, pp. 390-391