11. Especially of the secondary qualities of bodies.
The ideas that our complex ones of substances are made up of,
and about which our knowledge concerning substances is most employed, are those of their secondary qualities;
which depending all (as has been shown) upon the primary qualities of their minute and insensible parts; or, if not
upon them, upon something yet more remote from our comprehension; it is impossible we should know which
have a necessary union or inconsistency one with another. For, not knowing the root they spring from, not
knowing what size, figure, and texture of parts they are, on which depend, and from which result those qualities
which make our complex idea of gold, it is impossible we should know what other qualities result from, or are
incompatible with, the same constitution of the insensible parts of gold; and so consequently must always co-exist
with that complex idea we have of it, or else are inconsistent with it.