— 450 —
Our abstract Ideas are to us the measures of Species, instance in that of Man.       §22. There are Creatures in the World, that have shapes like
ours, but are hairy, and want Language, and Reason. There are
Naturals amongst us, that have perfectly our shape, but want
Reason, and some of them Language too. There are Creatures, as
’tis said, (sit fides penes Authorem, but there appears no contradiction,
that there should be such) that with Language, and Reason, and a
shape in other Things agreeing with ours, have hairy Tails; others
where the Males have no Beards, and others where the Females
have. If it be asked, whether these be all Men, or no, all of humane
Species; ’tis plain, the Question refers only to the nominal Essence:
For those of them to whom the definition of the Word Man, or the
complex Idea signified by that Name, agrees are Men, and the other
not. But if the Enquiry be made concerning the supposed real
Essence; and whether the internal Constitution and Frame of these
— 451 —
several Creatures be specifically different, it is wholly impossible
for us to answer, no part of that going into our specifick Idea: only
we have Reason to think, that where the Faculties, or outward
Frame so much differs, the internal Constitution is not exactly the
same: But, what difference in the internal real Constitution makes a
specifick difference, it is in vain to enquire; whilst our measures of
Species be, as they are, only our abstract Ideas, which we know; and
not that internal Constitution, which makes no part of them. Shall
the difference of Hair only on the Skin, be a mark of a different
internal specifick Constitution between a Changeling and a Drill,
when they agree in Shape, and want of Reason, and Speech? And
shall not the want of Reason and Speech, be a sign to us of different
real Constitutions and Species, between a Changeling, and a reason-
able Man? And so of the rest, if we pretend, that the distinction
of Species or Sorts is fixedly established by the real Frame, and
secret Constitutions of Things.
Locke Hum III, 6, §22, pp. 450-451