duals, depends on the mind of
man, variously collecting them, it is much more evident that they do so
in the more comprehensive classes, which, by the masters of logic, are
called genera. These are complex ideas designedly imperfect: and it is
visible at first sight, that several of those qualities that are to
be found in the things themselves are purposely left out of generical
ideas. For, as the mind, to make general ideas comprehending several
particulars, leaves out those of time and place, and such other, that
make them incommunicable to more than one individual; so to make other
yet more general ideas, that may comprehend different sorts, it leaves
out those qualities that distinguish them, and puts into its new
collection only such ideas as are common to several sorts. The same
convenience that made men express several parcels of yellow matter
coming from Guinea and Peru under one name, sets them also upon making
of one name that may comprehend both gold and silver, and some other
bodies of different sorts. This is done by leaving out those qualities,
which are peculiar to each sort, and retaining a complex idea made up
of those that are common to them all. To which the name METAL being
annexed, there is a genus constituted; the essence whereof being that
abstract idea, containing only malleableness and fusibility, with
certain degrees of weight and fixedness, wherein some bodies of several
kinds agree, leaves out the colour and other qualities peculiar to gold
and silver, and the other sorts comprehended under the name metal.
Whereby it is plain that men follow not exactly the patterns set them by
nature, when they make their general ideas of substances; since there is
no body to be found which has barely malleableness and fusibility in
it, without other qualities as inseparable as those. But men, in making
their general ideas, seeking more the convenience of language, and quick
dispatch by short and comprehensive signs, than the true and precise
nature of things as they exist, have, in the framing their abstract
ideas, chiefly pursued that end; which was to be furnished with store
of general and variously comprehensive names. So that in this whole
business of genera and species, the genus, or more comprehensive, is but
a partial conception of what is in the species; and the species but a
partial idea of what is to be found in each individual. If therefore any
one will think that a man, and a horse, and an animal,