es.

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.

12. Because necessary Connexion between any secondary and the primary
Qualities is undiscoverable by us.

Besides this ignorance of the primary qualities of the insensible parts
of bodies, on which depend all their secondary qualities, there is yet
another and more incurable part of ignorance, which sets us more remote
from a certain knowledge of the co-existence or INCO-EXISTENCE (if I may
so say) of different ideas in the same subject; and that is, that there
is no discoverable connexion between any secondary quality and those
primary qualities which it depends on.

13. We have no perfect knowledge of their Primary Qualities.

That the size, figure, and motion of one body should cause a change
in the size, figure, and motion of another body, is not beyond our
conception; the separation of the parts of one body upon the intrusion
of another; and the change from rest to motion upon impulse; these and
the like seem to have SOME CONNEXION one with another. And if we knew
these primary qualities of bodies, we might have reason to hope we might
be able to know a great deal more of these operations of them one upon
another: but our minds not being able to discover any connexion betwixt
these primary qualities of bodies and the sensations that are produced
in us by them, we can never be able to establish certain and undoubted
rules of the CONSEQUENCE or CO-EXISTENCE of any secondary qualities,
though we could discover the size, figure, or motion of those invisible
parts which immediately produce them. We are so far from k