[Footnote 1: Machiavelli recommends his Prince to make use of every moment that his neighbour is weak, in order to attack him; as otherwise his neighbour may do the same. If honour and fidelity prevailed in the world, it would be a different matter; but as these are qualities not to be expected, a man must not practise them himself, because he will meet with a bad return. It is just the same in a dispute: if I allow that my opponent is right as soon as he seems to be so, it is scarcely probable that he will do the same when the position is reversed; and as he acts wrongly, I am compelled to act wrongly too. It is easy to say that we must yield to truth, without any prepossession in favour of our own statements; but we cannot assume that our opponent will do it, and therefore we cannot do it either. Nay, if I were to abandon the position on which I had previously bestowed much thought, as soon as it appeared that he was right, it might easily happen that I might be misled by a momentary impression, and give up the truth in order to accept an error.]
To some extent every man is armed against such a procedure by his own cunning and villainy. He learns by daily experience, and thus comes to have his own _natural Dialectic_, just as he has his own _natural Logic_. But his Dialectic is by no means as safe a guide as his Logic. It is not so easy for any one to think or draw an inference contrary to the laws of Logic; false judgments are frequent, false conclusions very rare. A man cannot easily be deficient in natural Logic, but he may very easily be deficient in natural Dialectic, which is a gift apportioned in unequal measure. In so far natural Dialectic resembles the faculty of judgment, which differs in degree with every man; while reason, strictly speaking, is the same. For it often happens that in a matter in which a man is really in the right, he is confounded or refuted by merely superficial arguments; and if he emerges victorious from a contest, he owes it very often not so much to the correctness of his judgment in stating his proposition, as to the cunning and address with which he defended it.
Here, as in all other cases, the best gifts are born with a man; nevertheless, much may be done to make him a master of this art by practice, and also by a consideration of the tactics which may be used to defeat an opponent, or which he uses himself for a similar purpose. Therefore, even though Logic may be of no very real, practical use, Dialectic may certainly be so; and Aristotle, too, seems to me to have drawn up his Logic proper, or Analytic, as a foundation and preparation for his Dialectic, and to have made this his chief business. Logic is concerned with the mere form of propositions; Dialectic, with their contents or matter--in a word, with their substance. It was proper, therefore, to consider the general form of all propositions before proceeding to particulars.