ng the uncertainty
of medicine by postulating the uncertainty of all human knowledge. (3)
If, _vice versa_, two things follow one from the other, and one is to
be proved, you may postulate the other. (4) If a general proposition
is to be proved, you may get your opponent to admit every one of the
particulars. This is the converse of the second.[1]

[Footnote 1: _Idem_, chap. 11. The last chapter of this work contains
some good rules for the practice of Dialectics.]

VII.

Should the disputation be conducted on somewhat strict and formal
lines, and there be a desire to arrive at a very clear understanding,
he who states the proposition and wants to prove it may proceed
against his opponent by question, in order to show the truth of the
statement from his admissions. The erotematic, or Socratic, method was
especially in use among the ancients; and this and some of the tricks
following later on are akin to it.[1]

[Footnote 1: They are all a free version of chap. 15 of Aristotle's
_De Sophistici Elenchis_.]

The plan is to ask a great many wide-reaching questions at once, so as
to hide what you want to get admitted, and, on the other hand, quickly
propound the argument resulting from the admissions; for those who are
slow of understanding cannot follow accurately, and do not notice any
mistakes or gaps there may be in the demonstration.

VIII.

This trick consists in making your opponent angry; for when he is
angry he is incapable of judging aright, and perceiving where
his advantage lies. You can make him angry by doing him repeated
injustice, or practising some kind of chicanery, and being generally
insolent.

IX.

Or you may put questions in an order different from that which the
conclusion to be drawn from them requires, and transpose them, so
as not to let him know at what you are aiming. He can then take no
precautions. You may also use his answers for different or even
opposite conclusions, according to their character. This is akin to
the trick of masking your procedure.

X.

If you observe that your opponent designedly returns a negative answer
to the questions which, for the sake of your proposition, you want
him to answer in the affirmative, you must ask the converse of the
proposition, as though it were that which you were anxious to see
affirmed; or, at any rate, you may give him his choice of both, so
that he may not perceive which of them you are asking him to affirm.

XL.

If y