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been shown to be real); while if you want to overthrow a view, ask
what it is that is real if the thing in question be real, for if we
show that what follows from the thing in question is unreal, we shall
have demolished the thing in question.
Moreover, look at the time involved, to see if there be any
discrepancy anywhere: e.g. suppose a man to have stated that what is
being nourished of necessity grows: for animals are always of
necessity being nourished, but they do not always grow. Likewise,
also, if he has said that knowing is remembering: for the one is
concerned with past time, whereas the other has to do also with the
present and the future. For we are said to know things present and
future (e.g. that there will be an eclipse), whereas it is impossible
to remember anything save what is in the past.
Part 5
Moreover, there is the sophistic turn of argument, whereby we draw our
opponent into the kind of statement against which we shall be well
supplied with lines of argument. This process is sometimes a real
necessity, sometimes an apparent necessity, sometimes neither an
apparent nor a real necessity. It is really necessary whenever the
answerer has denied any view that would be useful in attacking the
thesis, and the questioner thereupon addresses his arguments to the
support of this view, and when moreover the view in question happens
to be one of a kind on which he has a good stock of lines of argument.
Likewise, also, it is really necessary whenever he (the questioner)
first, by an induction made by means of the view laid down, arrives at
a certain statement and then tries to demolish that statement: for
when once this has been demolished, the view originally laid down is
demolished as well. It is an apparent necessity, when the point to
which the discussion comes to be directed appears to be useful, and
relevant to the thesis, without being really so; whether it be that
the man who is standing up to the argument has refused to concede
something, or whether he (the questioner) has first reached it by a
plausible induction based upon the thesis and then tries to demolish
it. The remaining case is when the point to which the discussion comes
to be directed is neither really nor apparently necessary, and it is
the answerer's luck to be confuted on a mere side issue You should
beware of the last of the aforesaid methods; for it appears to be
wholly disconnected from, and foreign to, the art of dialectic. For
this reason, moreover, the answerer should not lose his temper, but
assent to those statements that are of no use in attacking the thesis,
adding an indication whenever he assents although he does not agree
with the view. For, as a rule, it increases the confusion of
questioners if, after all propositions of this kind have been granted
them, they can then draw no conclusion.
Moreover, any one who has made any statement whatever has in a certain
sense made several statements, inasmuch as each statement has a number
of necessary consequences: e.g. the man who said 'X is a man' has also
said that it is an animal and that it is animate and a biped and
capable of acquiring reason and knowledge, so that by the demolition
of any single one of these consequences, of whatever kind, the
original statement is demolished as well. But you should beware here
too of making a change to a more difficult subject: for sometimes the
consequence, and sometimes the original thesis, is the easier to
demolish.
Part 6
In regard to subjects which must have one and one only of two
predicates, as (e.g.) a man must have either a disease or health,
supposing we are well supplied as regards the one for arguing its
presence or absence, we shall be well equipped as regards the
remaining one as well. This rule is convertible for both purposes: for
when we have shown that the one attribute belongs, we shall have shown
that the remaining one does not belong; while if we show that the one
does not belong, we shall have shown that the remaining one does
belong. Clearly then the rule is useful for both purposes.