([Greek: syllogismos ex eikoton e semeion]).
The word syllogism in this connexion is a little puzzling. But it is
plain from the examples he gives that he meant here by syllogism not
even a correct reasoning, much less a reasoning in the explicit form
of three terms and three propositions. He used syllogism, in fact, in
the same loose sense in which we use the words reasoning and argument,
applying without distinction of good and bad.

The sign, he says, is taken in three ways, in as many ways as there
are Syllogistic Figures.

(1) A sign interpreted in the First Figure is conclusive. Thus: "This
person has been drowned, for he has froth in the trachea". Taken in
the First Figure with "All who have froth in the trachea have been
drowned" as a major premiss, this argument is valid. The sign is
conclusive.

(2) "This patient is fever-stricken, for he is thirsty." Assumed that
"All fever-stricken patients are thirsty," this is an argument in the
Second Figure, but it is not a valid argument. Thirst is a sign or
symptom of fever, but not a conclusive sign, because it is indicative
of other ailments also. Yet the argument has a certain probability.

(3) "Wise men are earnest ([Greek: spoudaioi]), for Pittacus is
earnest." Here the suppressed premiss is that "Pittacus is wise".
Fully expressed, the argument is in the Third Figure:--

Pittacus is earnest.
Pittacus is wise.
[.'.] Wise men are earnest.

Here again the argument is inconclusive and yet it has a certain
probability. The coincidence of wisdom with earnestness in one notable
example lends a certain air of probability to the general statement.

Such are Aristotle's examples or strict parallels to them. The
examples illustrate also what he says in his _Rhetoric_ as to the
advantages of enthymemes. For purposes of persuasion enthymemes are
better than explicit syllogisms, because any inconclusiveness there
may be in the argument is more likely to pass undetected. As we shall
see, one main use of the Syllogism is to force tacit assumptions into
light and so make their true connexion or want of connexion apparent.
In Logic enthymemes are recognised only to be shown up: the elliptical
expression is a cover for fallacy, which it is the business of the
logician to strip off.

In Aristotle's examples one of the premisses is expressed. But often
the arguments of common speech are even less explicit than this. A
general principle is vaguely hinted a