ly, as a psychic act. If we would understand
it fully, we must consider the act in its relations to the real
experience of ourselves and others. To fix this act, we give it a
separate name, calling it the conception: and then we must go behind
the activity of the mind to the objects on which it is exercised.
The element of fixity is found in them. And here also the truth of
Nominalism comes in. By means of words we enter into communication
with other minds. It is thus that we discover what is real, and what
is merely personal to ourselves.

[Footnote 1: The only objection to these terms is that they
have slipped from their moorings in philosophical usage. Thus
instead of Leibnitz's use of Intuitive and Symbolical, which
corresponds to the above distinction between Imaging and
Conception, Mr. Jevons employs the terms to express a
distinction among conceptions proper. We can understand what
a chiliagon means, but we cannot form an image of it in our
minds, except in a very confused and imperfect way; whereas we
can form a distinct image of a triangle. Mr. Jevons would call
the conception of the triangle _Intuitive_, of the chiliagon
_Symbolical_.

Again, while Mansel uses the words Presentative and
Representative to express our distinction, a more common
usage is to call actual Perception Presentative Knowledge, and
ideation or recollection in idea Representative.]

PART III.

THE INTERPRETATION OF PROPOSITIONS.--OPPOSITION AND IMMEDIATE
INFERENCE.

CHAPTER I.

THEORIES OF PREDICATION.--THEORIES OF JUDGMENT.

We may now return to the Syllogistic Forms, and the consideration of
the compatibility or incompatibility, implication, and interdependence
of propositions.

It was to make this consideration clear and simple that what we have
called the Syllogistic Form of propositions was devised. When are
propositions incompatible? When do they imply one another? When do
two imply a third? We have seen in the Introduction how such questions
were forced upon Aristotle by the disputative habits of his time.
It was to facilitate the answer that he analysed propositions into
Subject and Predicate, and viewed the Predicate as a reference to a
class: in other words, analysed the Predicate further into a Copula
and a Class Term.

But before showing how he exhibited the interconnexion of propositions
on this plan, we may turn aside to consider various so