uestion of
policy outside the limits of Logic. It is for the logician to expound
the method of Definition and the conditions of its application: how
far there are subjects that do not admit of its application profitably
must be decided on other grounds. But it is probably true that no
man who declines to be bound by a formal definition of his terms is
capable of carrying them in a clear unambiguous sense through a heated
controversy.

[Footnote 1: Except, perhaps, in new offices to which the
name is extended, such as _Clerk_ of School Board. The name,
bearing its most simple and common meaning, may cause popular
misapprehension of the nature of the duties. Any uncertainty
in meaning may be dangerous in practice: elections have been
affected by the ambiguity of this word.]

[Footnote 2: Sidgwick's _Political Economy_, pp. 52-3. Ed.
1883.]

[Footnote 3: Some logicians, however, speak of defining a
thing, and illustrate this as if by a thing they meant a
concrete individual, the realistic treatment of Universals
lending itself to such expressions. But though the authority
of Aristotle might be claimed for this, it is better to
confine the name in strictness to the main process of defining
a class. Since, however, the method is the same whether it is
an individual or a class that we want to make distinct, there
is no harm in the extension of the word definition to both
varieties. See Davidson's _Logic of Definition_, chap. ii.]

[Footnote 4: See Davidson's _Logic of Definition_, chap. iii.]

CHAPTER II.

THE FIVE PREDICABLES.--VERBAL AND REAL PREDICATION.

We give a separate chapter to this topic out of respect for the space
that it occupies in the history of Logic. But except as an exercise in
subtle distinction for its own sake, all that falls to be said about
the Predicables might be given as a simple appendix to the chapter on
Definition.

Primarily, the Five Predicables or Heads of Predicables--Genus,
Species, Differentia, Proprium, and Accidens--are not predicables at
all, but merely a list or enumeration of terms used in dividing and
defining on the basis of attributes. They have no meaning except in
connexion with a fixed scheme of division. Given such a scheme, and
we can distinguish in it the whole to be divided (the _genus_), the
subordinate divisions (the _species_), the attribute or combination of
attributes on which e