I am of opinion, therefore, that a sharper distinction should be drawn between Dialectic and Logic than Aristotle has given us; that to Logic we should assign objective truth as far as it is merely formal, and that Dialectic should be confined to the art of gaining one’s point, and contrarily, that Sophistic and Eristic should not be distinguished from Dialectic in Aristotle’s fashion, since the difference which he draws rests on objective and material truth; and in regard to what this is, we cannot attain any clear certainty before discussion; but we are compelled, with Pilate, to ask, What is truth? For truth is in the depths, [Greek: en butho hae halaetheia] (a saying of Democritus, Diog. Laert., ix., 72). Two men often engage in a warm dispute, and then return to their homes each of the other’s opinion, which he has exchanged for his own. It is easy to say that in every dispute we should have no other aim than the advancement of truth; but before dispute no one knows where it is, and through his opponent’s arguments and his own a man is misled.]
We must always keep the subject of one branch of knowledge quite distinct from that of any other. To form a clear idea of the province of Dialectic, we must pay no attention to objective truth, which is an affair of Logic; we must regard it simply as the art of getting the best of it in a dispute, which, as we have seen, is all the easier if we are actually in the right. In itself Dialectic has nothing to do but to show how a man may defend himself against attacks of every kind, and especially against dishonest attacks; and, in the same fashion, how he may attack another man’s statement without contradicting himself, or generally without being defeated. The discovery of objective truth must be separated from the art of winning acceptance for propositions; for objective truth is an entirely different matter: it is the business of sound judgment, reflection and experience, for which there is no special art.
Such, then, is the aim of Dialectic. It has been defined as the Logic of appearance; but the definition is a wrong one, as in that case it could only be used to repel false propositions. But even when a man has the right on his side, he needs Dialectic in order to defend and maintain it; he must know what the dishonest tricks are, in order to meet them; nay, he must often make use of them himself, so as to beat the enemy with his own weapons.
Accordingly, in a dialectical contest we must put objective truth aside, or, rather, we must regard it as an accidental circumstance, and look only to the defence of our own position and the refutation of our opponent’s.
In following out the rules to this end, no respect should be paid to objective truth, because we usually do not know where the truth lies. As I have said, a man often does not himself know whether he is in the right or not; he often believes it, and is mistaken: both sides often believe it. Truth is in the depths. At the beginning of a contest each man believes, as a rule, that right is on his side; in the course of it, both become doubtful, and the truth is not determined or confirmed until the close.