Книга только для ознакомления
.
(Suppose for instance we start with the two contradictories, Feathered
and Unfeathered; we shall find that the ant, the glow-worm, and some
other animals fall under both divisions.) For each differentia must be
presented by some species. There must be some species, therefore,
under the privative heading. Now specifically distinct animals
cannot present in their essence a common undifferentiated element, but
any apparently common element must really be differentiated. (Bird and
Man for instance are both Two-footed, but their two-footedness is
diverse and differentiated. So any two sanguineous groups must have
some difference in their blood, if their blood is part of their
essence.) From this it follows that a privative term, being
insusceptible of differentiation, cannot be a generic differentia;
for, if it were, there would be a common undifferentiated element in
two different groups.
Again, if the species are ultimate indivisible groups, that is,
are groups with indivisible differentiae, and if no differentia be
common to several groups, the number of differentiae must be equal
to the number of species. If a differentia though not divisible
could yet be common to several groups, then it is plain that in virtue
of that common differentia specifically distinct animals would fall
into the same division. It is necessary then, if the differentiae,
under which are ranged all the ultimate and indivisible groups, are
specific characters, that none of them shall be common; for otherwise,
as already said, specifically distinct animals will come into one
and the same division
|
