then
looks as if his proposition gave rise to others which are inconsistent
either with themselves or with some acknowledged truth, and so it
appears to be indirectly refuted. This is the _diversion_, and it is
another application of the fallacy _non causae ut causae_.

XXV.

This is a case of the _diversion_ by means of an _instance to the
contrary_. With an induction ([Greek: epagogae]), a great number
of particular instances are required in order to establish it as a
universal proposition; but with the _diversion_ ([Greek: apagogae]) a
single instance, to which the proposition does not apply, is all that
is necessary to overthrow it. This is a controversial method known
as the _instance_--_instantia_, [Greek: enstasis]. For example, "all
ruminants are horned" is a proposition which may be upset by the
single instance of the camel. The _instance_ is a case in which a
universal truth is sought to be applied, and something is inserted in
the fundamental definition of it which is not universally true, and by
which it is upset. But there is room for mistake; and when this trick
is employed by your opponent, you must observe (1) whether the example
which he gives is really true; for there are problems of which the
only true solution is that the case in point is not true--for example,
many miracles, ghost stories, and so on; and (2) whether it really
comes under the conception of the truth thus stated; for it may only
appear to do so, and the matter is one to be settled by precise
distinctions; and (3) whether it is really inconsistent with this
conception; for this again may be only an apparent inconsistency.

XXVI.

A brilliant move is the _retorsio argumenti_, or turning of the
tables, by which your opponent's argument is turned against himself.
He declares, for instance, "So-and-so is a child, you must make
allowance for him." You retort, "Just because he is a child, I must
correct him; otherwise he will persist in his bad habits."

XXVII.

Should your opponent surprise you by becoming particularly angry at an
argument, you must urge it with all the more zeal; not only because it
is a good thing to make him angry, but because it may be presumed that
you have here put your finger on the weak side of his case, and that
just here he is more open to attack than even for the moment you
perceive.

XXVIII.

This is chiefly practicable in a dispute between scholars in the
presence of the unlearned. If you h