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

CHAPTER V.
MEDIATE INFERENCE AND THE ARISTOTELIAN SYLLOGISM.
i. WE have dealt with the forms of Immediate
Inference, in which from a single proposition we
derived another, stating the same relation between S
and P, but from a different point of view, as it were ;
in Conversion, for instance, we find what the given
in Obver-
proposition tells us of the relation of P to S ;
sion, of S to not-P, and so forth.
The question has been raised whether these changes
in a given proposition have a right to be called Infer
ence. We defined Inference (ch.
I.
7) as a process
in which from given facts, or given propositions, we
pass to a new proposition distinct from them i.e., to
a new fact or truth. This does not mean an absolutely
new proposition. Such a proposition would be uncon
nected with the premises i.e., would be absolutely dis
continuous with previous knowledge. It would be a
contradiction in terms to say that such a proposition
was inferred at all. But the conclusion of an inference
states a relation which is not stated in any one pro
position among those which form the premises. Now
in Immediate Inference we do not pass to a proposition
which is
"
"
new even in this second sense of the word ;
for the conclusion states no new relation. On the
other hand,
in Immediate Inference we have not