— 416 —
Each distinct abstract Idea is a distinct Essence.       §14. Nor will any one wonder, that I say these Essences, or abstract
Ideas, (which are the measures of Names, and the boundaries of
Species) are the Workmanship of the Understanding, who considers,
that at least the complex ones are often, in several Men, different
Collections of simple Ideas: and therefore that is Covetousness to one
Man, which is not so to another. Nay, even in Substances, where
their abstract Ideas seem to be taken from the Things themselves,
they are not constantly the same; no not in that Species, which is
most familiar to us, and with which we have the most intimate
acquaintance: It having been more than once doubted, whether the
Foetus born of a Woman were a Man, even so far, as that it hath been
debated, whether it were, or were not to be nourished and baptized:
which could not be, if the abstract Idea or Essence, to which the
Name Man belonged, were of Nature’s making; and were not the
uncertain and various Collection of simple Ideas, which the Under-
standing puts together, and then abstracting it, affixed a name to
it. So that in truth every distinct abstract Idea, is a distinct Essence: and
the names that stand for such distinct Ideas, are the names of Things
essentially different. Thus a Circle is as essentially different from an
Oval, as a Sheep from a Goat: and Rain is as essentially different
from Snow, as Water from Earth; that abstract Idea which is the
Essence of one, being impossible to be communicated to the other.
And thus any two abstract Ideas, that in any part vary one from
another, with two distinct names annexed to them, constitute two
— 417 —
distinct sorts, or, if you please, Species, as essentially different, as any
two the most remote, or opposite in the World.
Locke Hum III, 3, §14, pp. 416-417