An introductory text-book of logic - Mellone, Sydney - Rare Books at ...

1 68 THE PREDICABLES.
of sides definitely three, then we have the concept of
the triangle, a three-sided rectilineal figure ; this is a
species subordinate to the genus,
which includes it
along with other species. The distinguishing attribute
of the species, peculiar to it and distinguishing it from
other species of the same genus, is an example of what
we called the "difference," Aristotle s Siafopd.
For Logic, any pair of classes of which one is subordinate
to the other are related as species and genus. But in Nat
ural History, these terms are given a particular place within
a hierarchy of divisions and subdivisions :
"
Group,"
Sub-species
genus
"
Kingdom,"
"
"
"
"
"
Class," Order," Family," Genus," Species,"
"
(if necessary). Logically, each of these is
to the one which follows it.
The relation of
"
subordination
between objects of the same kind ; "yellow"
"
only holds good
is not the
but of the various shades
generic concept of "gold,"
of yellow; although the concept "gold" includes the
idea of a colour which is a peculiar shade of yellow.
(b) Proprium.
Properties which belong to the whole of a class, and
are peculiar to it, are called propria, tSia. They are
inseparable ;
"
nor the leopard his spots."
the Ethiopian cannot change his skin,
All such properties are, as it were, a challenge to
our Reason, to show that they are connected with the
specific concept of the class, and follow from it. They
may follow as "consequent from reason," or as "effect
from cause." Examples of t\\z former are found in the
cases where any characteristic and peculiar property is
found to follow from the definition of the figure (e.g.,
Euclid, Bk. I.
32). Examples of the latter will be
found in the various explanatory sciences e.g., when