18. The names of simple ideas the least doubtful.
From what has been said, it is easy to observe what has been
before remarked, viz., that the names of simple ideas are, of all others, the least liable to mistakes, and that for
these reasons. First, Because the ideas they stand for, being each but one single perception, are much easier got,
and more clearly retained, than the more complex ones, and therefore are not liable to the uncertainty which
usually attends those compounded ones of substances and mixed modes, in which the precise number of simple
ideas that make them up are not easily agreed, so readily kept in mind. And, Secondly, Because they are never
referred to any other essence, but barely that perception they immediately signify: which reference is that which
renders the signification of the names of substances naturally so perplexed, and gives occasion to so many
disputes. Men that do not perversely use their words, or on purpose set themselves to cavil, seldom mistake, in
any language which they are acquainted with, the use and signification of the name of simple ideas. White and
sweet, yellow and bitter, carry a very obvious meaning with them, which every one precisely comprehends, or
easily perceives he is ignorant of, and seeks to be informed. But what precise collection of simple ideas modesty
or frugality stand for, in another's use, is not so certainly known. And however we are apt to think we well enough
know what is meant by gold or iron; yet the precise complex idea others make them the signs of is not so certain:
and I believe it is very seldom that, in speaker and hearer, they stand for exactly the same collection. Which must
needs produce mistakes and disputes, when they are made use of in discourses, wherein men have to do with
universal propositions, and would settle in their minds universal truths, and consider the consequences that follow
from them.
