An Essay Concerning Humane Understanding, Volume II. | Page 7

shame of not being able to do it. But though defining by
GENUS and DIFFERENTIA (I crave leave to use these terms of art,
though originally Latin, since they most properly suit those notions
they are applied to), I say, though defining by the GENUS be the
shortest way, yet I think it may be doubted whether it be the best. This I
am sure, it is not the only, and so not absolutely necessary. For,
definition being nothing but making another understand by words what
idea the term defined stands for, a definition is best made by
enumerating those simple ideas that are combined in the signification
of the term defined: and if, instead of such an enumeration, men have
accustomed themselves to use the next general term, it has not been out
of necessity, or for greater clearness, but for quickness and dispatch
sake. For I think that, to one who desired to know what idea the word
MAN stood for; if it should be said, that man was a solid extended
substance, having life, sense, spontaneous motion, and the faculty of
reasoning, I doubt not but the meaning of the term man would be as
well understood, and the idea it stands for be at least as clearly made
known, as when it is defined to be a rational animal: which, by the
several definitions of ANIMAL, VIVENS, and CORPUS, resolves
itself into those enumerated ideas. I have, in explaining the term MAN,
followed here the ordinary definition of the schools; which, though
perhaps not the most, exact, yet serves well enough to my present
purpose. And one may, in this instance, see what gave occasion to the
rule, that a definition must consist of GENUS and DIFFERENTIA; and
it suffices to show us the little necessity there is of such a rule, or
advantage in the strict observing of it. For, definitions, as has been said,
being only the explaining of one word by several others, so that the
meaning or idea it stands for may be certainly known; languages are
not always so made according to the rules of logic, that every term can
have its signification exactly and clearly expressed by two others.
Experience sufficiently satisfies us to the contrary; or else those who
have made this rule have done ill, that they have given us so few

definitions conformable to it. But of definitions more in the next
chapter.
11. General and Universal are Creatures of the Understanding, and
belong not to the Real Existence of things.
To return to general words: it is plain, by what has been said, that
GENERAL and UNIVERSAL belong not to the real existence of things;
but are the inventions and creatures of the understanding, made by it for
its own use, and concern only signs, whether words or ideas. Words are
general, as has been said, when used for signs of general ideas, and so
are applicable indifferently to many particular things; and ideas are
general when they are set up as the representatives of many particular
things: but universality belongs not to things themselves, which are all
of them particular in their existence, even those words and ideas which
in their signification are general. When therefore we quit particulars,
the generals that rest are only creatures of our own making; their
general nature being nothing but the capacity they are put into, by the
understanding, of signifying or representing many particulars. For the
signification they have is nothing but a relation that, by the mind of
man, is added to them.
12. Abstract Ideas are the Essences of Genera and Species.
The next thing therefore to be considered is, What kind of signification
it is that general words have. For, as it is evident that they do not
signify barely one particular thing; for then they would not be general
terms, but proper names, so, on the other side, it is as evident they do
not signify a plurality; for MAN and MEN would then signify the same;
and the distinction of numbers (as the grammarians call them) would be
superfluous and useless. That then which general words signify is a
SORT of things; and each of them does that, by being a sign of an
abstract idea in the mind; to which idea, as things existing are found to
agree, so they come to be ranked under that name, or, which is all one,
be of that sort. Whereby it is evident that the ESSENCES of the sorts,
or, if the Latin word pleases better, SPECIES of things, are nothing else
but these abstract ideas. For the having the essence of any species,
being that which makes anything to be of that species; and the

conformity to the idea to which the name is annexed being