end of speech, to declare his
meaning, and make known what idea he makes it stand for. This, as
has been shown, cannot be done by definition: and therefore, when a
synonymous word fails to do it, there is but one of these ways left.
First, Sometimes the NAMING the subject wherein that simple idea is
to be found, will make its name to be understood by those who are
acquainted with that subject, and know it by that name. So to make a
countryman understand what FEUILLEMORTE colour signifies, it may suffice
to tell him, it is the colour of withered leaves falling in autumn.
Secondly, but the only sure way of making known the signification of the
name of any simple idea, is BY PRESENTING TO HIS SENSES THAT SUBJECT
WHICH MAY PRODUCE IT IN HIS MIND, and make him actually have the idea
that word stands for.

15. In mixed Modes, by Definition.

II. Secondly, Mixed modes, especially those belonging to morality, being
most of them such combinations of ideas as the mind puts together of its
own choice, and whereof there are not always standing patterns to be
found existing, the signification of their names cannot be made known,
as those of simple ideas, by any showing: but, in recompense thereof,
may be perfectly and exactly defined. For they being combinations of
several ideas that the mind of man has arbitrarily put together, without
reference to any archetypes, men may, if they please, exactly know the
ideas that go to each composition, and so both use these words in a
certain and undoubted signification, and perfectly declare, when there
is occasion, what they stand for. This, if well considered, would lay
great blame on those who make not their discourses about MORAL things
very clear and distinct. For since the precise signification of the
names of mixed modes, or, which is all one, the real essence of each
species is to be known, they being not of nature's, but man's making, it
is a great negligence and perverseness to discourse of moral things
with uncertainty and obscurity; which is more pardonable in treating of
natural substances, where doubtful terms are hardly to be avoided, for a
quite contrary reason, as we shall see by and by.

16. Morality capable of Demonstration.

Upon this ground it is that I am bold to think that morality is capable
of demonstration, as well as mathematics: since the precise real essence
of the things moral words stand for may be perfectly known, and so
the congruity and incongruity of