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

126 MEDIATE INFERENCE
hence there is no real middle term at all, but practically
four terms.
Consider the premises, "All rash men are confident;
all brave men are confident." These propositions tell us
nothing about the relation
"
"
of the rash
to "the brave"; they only tell us that
the rash are a part of the
"
class of con
fident persons," and the brave are also a
part, as fig. 21 shows. The premises
allow of the circles "rash" and "brave"
being placed anywhere within the circle
or outside
"
confident," either overlapping
of each other. Jevons adds an example
in which all the propositions are true,
while the argument has an undistributed middle. "The two
propositions, All Frenchmen are Europeans ;
all Parisians
are Europeans, do not enable us to infer that all Parisians
are Frenchmen. For though we know, of course, that all
Parisians are included among Frenchmen, the premises
would allow of their being placed anywhere within the
circle of Europeans."
The fourth is a double rule, (a)
The minor term
must not be distributed in the conclusion unless it is
distributed in the premise in which it occurs ; the
breach of this rule is called an illicit process of the
minor, (fr) The major
term must not be distributed in
the conclusion unless it is distributed in the premise in
which it occurs ; the breach of this rule is called an
illicit process of the major. The proof of the rules con
sists in seeing that
"
if an assertion is not made about
the whole of a term in the premises, it cannot be made
about the whole of that term in the conclusion without
going beyond what has been given." The conclusion
must be no more definite than the premises warrant.
We take again an example given by Jevons.
"
If we
were to argue that because many nations are capable