give him the
counter-proposition as well, leaving him his choice of the two; and
you must render the contrast as glaring as you can, so that to avoid
being paradoxical he will accept the proposition, which is thus made
to look quite probable. For instance, if you want to make him admit
that a boy must do everything that his father tells him to do, ask him
"whether in all things we must obey or disobey our parents." Or, if
a thing is said to occur "often," ask whether by "often" you are to
understand few or many cases; and he will say "many." It is as though
you were to put grey next black, and call it white; or next white, and
call it black.

XIV.

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_.

XV.

If you have advanced a paradoxical proposition and find a difficulty
in proving it, you may submit for your opponent's acceptance or
rejection some true proposition, the truth of which, however, is not
quite palpable, as though you wished to draw your proof from it.
Should he reject it because he suspects a trick, you can obtain your
triumph by showing how absurd he is; should he accept it> you have got
reason on your side for the moment, and must now look about you; or
else you can employ the previous trick as well, and maintain that your
paradox is proved by the proposition which he has accepted. For this
an extreme degree of impudence is required; but experience shows cases
of it, and there are people who practise it by instinct.

XVI.

Another trick is to use arguments _ad hominem_, or _ex concessis_[1]
When your opponent makes a proposition, you must try to see whether it
is not in some way--if needs be, only apparently--inconsistent with
some other proposition which he has made or admitted, or with the
principles of a school or sect which he has commended and approved, or
with the actions of those who support the sect, or else of those who
give it only an apparent and spurious support, or with his own actions
or want of action. For