that is put to stand for it must be very
uncertain in its application; and it will be impossible to know what
things are or ought to be called a HORSE, or ANTIMONY, when those words
are put for real essences that we have no ideas of at all. And therefore
in this supposition, the names of substances being referred to standards
that cannot be known, their significations can never be adjusted and
established by those standards.

13. Secondly, To co-existing Qualities, which are known but imperfectly.

Secondly, The simple ideas that are FOUND TO CO-EXIST IN SUBSTANCES
being that which their names immediately signify, these, as united in
the several sorts of things, are the proper standards to which their
names are referred, and by which their significations may be best
rectified. But neither will these archetypes so well serve to this
purpose as to leave these names without very various and uncertain
significations. Because these simple ideas that co-exist, and are united
in the same subject, being very numerous, and having all an equal right
to go into the complex specific idea which the specific name is to stand
for, men, though they propose to themselves the very same subject to
consider, yet frame very different ideas about it; and so the name they
use for it unavoidably comes to have, in several men, very different
significations. The simple qualities which make up the complex ideas,
being most of them powers, in relation to changes which they are apt
to make in, or receive from other bodies, are almost infinite. He that
shall but observe what a great variety of alterations any one of the
baser metals is apt to receive, from the different application only of
fire; and how much a greater number of changes any of them will receive
in the hands of a chymist, by the application of other bodies, will not
think it strange that I count the properties of any sort of bodies not
easy to be collected, and completely known, by the ways of inquiry which
our faculties are capable of. They being therefore at least so many,
that no man can know the precise and definite number, they are
differently discovered by different men, according to their various
skill, attention, and ways of handling; who therefore cannot choose
but have different ideas of the same substance, and therefore make the
signification of its common name very various and uncertain. For the
complex ideas of substances, being made up of such simple ones as are
supp