-called Theories
of Predication or of Judgment. Strictly speaking, they are not
altogether relevant to Logic, that is to say, as a practical science:
they are partly logical, partly psychological theories: some of
them have no bearing whatever on practice, but are matters of pure
scientific curiosity: but historically they are connected with the
logical treatment of propositions as having been developed out of
this.

The least confusing way of presenting these theories is to state
them and examine them both logically and psychologically. The logical
question is, Has the view any advantage for logical purposes? Does it
help to prevent error, to clear up confusion? Does it lead to firmer
conceptions of the truth? The psychological question is, Is this a
correct theory of how men actually think when they make propositions?
It is a question of _what is_ in the one case, and of _what ought to
be for a certain purpose_ in the other.

Whether we speak of Proposition or of Judgment does not materially
affect our answer. A Judgment is the mental act accompanying a
Proposition, or that may be expressed in a proposition and cannot be
expressed otherwise: we can give no other intelligible definition or
description of a judgment. So a proposition can only be defined as the
expression of a judgment: unless there is a judgment underneath them,
a form of words is not a proposition.

Let us take, then, the different theories in turn. We shall find that
they are not really antagonistic, but only different: that each is
substantially right from its own point of view: and that they seem to
contradict one another only when the point of view is misunderstood.

I. _That the Predicate term may be regarded as a class in or
from which the Subject is included or excluded._ Known as the
Class-Inclusion, Class-Reference, or Denotative view.

This way of analysing propositions is possible, as we have seen,
because every statement implies a general name, and the extension
or denotation of a general name is a class defined by the common
attribute or attributes. It is useful for syllogistic purposes:
certain relations among propositions can be most simply exhibited in
this way.

But if this is called a Theory of Predication or Judgment, and taken
psychologically as a theory of what is in men's minds whenever they
utter a significant Sentence, it is manifestly wrong. When discussed
as such, it is very properly rejected. When a man says "P struck