Passed on by my friend, The Art of Controversy, by Arthur Schopenhauer.
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. 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.One of my favorite strategems:
Stratagem IThen there's always this classic:
The Extension. - This consists in carrying your opponent's proposition beyond its natural limits; in giving it as general a signification and as wide a sense as possible, so as to exaggerate it; and, on the other hand, in giving your own proposition as restricted a sense and as narrow limits as you can, because the more general a statement becomes, the more numerous are the objections to which it is open. The defence consists in an accurate statement of the point or essential question at issue.
Stratagem XIVThere's lots, lots more, and you know it has to be good because it's translated from German.
This, which is an impudent trick, is played as follows: When your opponent has answered several of your questions without the answers turning out favourable to the conclusion at which you are aiming, advance the desired conclusion, - although it does not in the least follow, - as though it had been proved, and proclaim it in a tone of triumph. If your opponent is shy or stupid, and you yourself possess a great deal of impudence and a good voice, the trick may easily succeed. It is akin to the fallacy non causae ut causae.