17. Definitions can make moral discourses clear.
This I have here mentioned, by the by, to show of what
consequence it is for men, in their names of mixed modes, and consequently in all their moral discourses, to
define their words when there is occasion: since thereby moral knowledge may be brought to so great clearness
and certainty. And it must be great want of ingenuousness (to say no worse of it) to refuse to do it: since a
definition is the only way whereby the precise meaning of moral words can be known; and yet a way whereby
their meaning may be known certainly, and without leaving any room for any contest about it. And therefore the
negligence or perverseness of mankind cannot be excused, if their discourses in morality be not much more clear
than those in natural philosophy: since they are about ideas in the mind, which are none of them false or
disproportionate; they having no external beings for the archetypes which they are referred to and must
correspond with. It is far easier for men to frame in their minds an idea, which shall be the standard to which they
will give the name justice; with which pattern so made, all actions that agree shall pass under that denomination,
than, having seen Aristides, to frame an idea that shall in all things be exactly like him; who is as he is, let men
make what idea they please of him. For the one, they need but know the combination of ideas that are put together
in their own minds; for the other, they must inquire into the whole nature, and abstruse hidden constitution, and
various qualities of a thing existing without them.
