ercourse between
two rational beings, and also by acquaintance with the means which
disputants adopt in order to make good against one another their own
individual thought, and to show that it is pure and objective. For
human nature is such that if A. and B. are engaged in thinking in
common, and are communicating their opinions to one another on any
subject, so long as it is not a mere fact of history, and A. perceives
that B.'s thoughts on one and the same subject are not the same as his
own, he does not begin by revising his own process of thinking, so as
to discover any mistake which he may have made, but he assumes that
the mistake has occurred in B.'s. In other words, man is naturally
obstinate; and this quality in him is attended with certain results,
treated of in the branch of knowledge which I should like to call
Dialectic, but which, in order to avoid misunderstanding, I shall call
Controversial or Eristical Dialectic. Accordingly, it is the branch
of knowledge which treats of the obstinacy natural to man. Eristic is
only a harsher name for the same thing.

Controversial Dialectic is the art of disputing, and of disputing in
such a way as to hold one's own, whether one is in the right or the
wrong--_per fas et nefas_.[1] A man may be objectively in the right,
and nevertheless in the eyes of bystanders, and sometimes in his own,
he may come off worst. For example, I may advance a proof of some
assertion, and my adversary may refute the proof, and thus appear to
have refuted the assertion, for which there may, nevertheless, be
other proofs. In this case, of course, my adversary and I change
places: he comes off best, although, as a matter of fact, he is in the
wrong.

[Footnote 1: According to Diogenes Laertius, v., 28, Aristotle put
Rhetoric and Dialectic together, as aiming at persuasion, [Greek: to
pithanon]; and Analytic and Philosophy as aiming at truth. Aristotle
does, indeed, distinguish between (1) _Logic_, or Analytic, as the
theory or method of arriving at true or apodeictic conclusions; and
(2) _Dialectic_ as the method of arriving at conclusions that are
accepted or pass current as true, [Greek: endoxa] _probabilia_;
conclusions in regard to which it is not taken for granted that they
are false, and also not taken for granted that they are true in
themselves, since that is not the point. What is this but the art of
being in the right, whether one has any reason for being so or not, in
other words