is wrought up by ratiocination has been exceedingly
practised by Aristotle, and the Peripatetics, and Theophrastus; and
after them by those rhetoricians who are accounted the most elegant
and the most skilful. And it seems desirable to explain why that
arrangement is more approved of by us, that we may not appear to have
adopted it capriciously; at the same time we must be brief in the
explanation, that we may not appear to dwell on such subjects longer
than the general manner of laying down rules requires.

XXXVI. If in any sort of argumentation it is sufficient to use a
proposition by itself, and if it is not requisite to add proof to the
proposition; but if in any sort of argumentation a proposition is of
no power unless proof be added to it; then proof is something distinct
from the proposition. For that which can be joined to a thing or
separated from it, cannot possibly be the same thing with that to
which it is joined or from which it is separated. But there is a
certain kind of argumentation in which the proposition does not
require confirmatory proof, and also another kind in which it is of
no use at all without such proof, as we shall show. Proof, then, is a
thing different from a proposition. And we will demonstrate that point
which we have promised to show in this way:--The proposition which
contains in itself something manifest, because it is unavoidable that
that should be admitted by all men, has no necessity for our desiring
to prove and corroborate it.

It is a sort of statement like this:--"If on the day on which that
murder was committed at Rome, I was at Athens, I could not have been
present at that murder." Because this is manifestly true, there is no
need to adduce proof of it; wherefore, it is proper at once to assume
the fact, in this way:--"But I was at Athens on that day." If this is
not notorious, it requires proof; and when the proof is furnished the
conclusion must follow:--"Therefore I could not have been present at
the murder." There is, therefore, a certain kind of proposition which
does not require proof. For why need one waste time in proving that
there is a kind which does require proof; for that is easily visible
to all men. And if this be the case, from this fact, and from that
statement which we have established, it follows that proof is
something distinct from a proposition. And if it is so, it is
evidently false that argumentation is susceptible of only three
divisions.

In th