The Complete Aristotle (eng.)

doctrine ‘not to be
directed against the thought’. For if not all are directed against
either expression or thought, there will be certain other arguments
directed neither against the expression nor against the thought,
whereas they say that all must be one or the other, and divide them
all as directed either against the expression or against the
thought, while others (they say) there are none. But in point of
fact those that depend on mere expression are only a branch of
those syllogisms that depend on a multiplicity of meanings. For the
absurd statement has actually been made that the description
‘dependent on mere expression’ describes all the arguments that
depend on language: whereas some of these are fallacies not because
the answerer adopts a particular attitude towards them, but because
the argument itself involves the asking of a question such as bears
more than one meaning.
    It is, too, altogether absurd to discuss Refutation without
first discussing Proof: for a refutation is a proof, so that one
ought to discuss proof as well before describing false refutation:
for a refutation of that kind is a merely apparent proof of the
contradictory of a thesis. Accordingly, the reason of the falsity
will be either in the proof or in the contradiction (for mention of
the ‘contradiction’ must be added), while sometimes it is in both,
if the refutation be merely apparent. In the argument that speaking
of the silent is possible it lies in the contradiction, not in the
proof; in the argument that one can give what one does not possess,
it lies in both; in the proof that Homer’s poem is a figure through
its being a cycle it lies in the proof. An argument that does not
fail in either respect is a true proof.
    But, to return to the point whence our argument digressed, are
mathematical reasonings directed against the thought, or not? And
if any one thinks ‘triangle’ to be a word with many meanings, and
granted it in some different sense from the figure which was proved
to contain two right angles, has the questioner here directed his
argument against the thought of the former or not?
    Moreover, if the expression bears many senses, while the
answerer does not understand or suppose it to have them, surely the
questioner here has directed his argument against his thought! Or
how else ought he to put his question except by suggesting a
distinction-suppose one’s question to be speaking of the silent
possible or not?’-as follows, ‘Is the answer “No” in one sense, but
“Yes” in another?’ If, then, any one were to answer that it was not
possible in any sense and the other were to argue that it was, has
not his argument been directed against the thought of the answerer?
Yet his argument is supposed to be one of those that depend on the
expression. There is not, then, any definite kind of arguments that
is directed against the thought. Some arguments are, indeed,
directed against the expression: but these are not all even
apparent refutations, let alone all refutations. For there are also
apparent refutations which do not depend upon language, e.g. those
that depend upon accident, and others.
    If, however, any one claims that one should actually draw the
distinction, and say, ‘By “speaking of the silent” I mean, in one
sense this and in the other sense that’, surely to claim this is in
the first place absurd (for sometimes the questioner does not see
the ambiguity of his question, and he cannot possibly draw a
distinction which he does not think to be there): in the second
place, what else but this will didactic argument be? For it will
make manifest the state of the case to one who has never
considered, and does not know or suppose that there is any other
meaning but one. For what is there to prevent the same thing also
happening to us in cases where there is no double meaning? ‘Are the
units in four equal to the twos? Observe that the twos are
contained in four in one sense in this way, in another sense in
that’. Also, ‘Is the knowledge of contraries one or not? Observe
that some contraries are known, while others are unknown’. Thus the
man who makes this claim seems to be unaware of the difference
between didactic and dialectical argument, and of the fact that
while he who argues didactically should not ask questions but make
things clear himself, the other should merely ask questions.
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11
    Moreover, to claim a ‘Yes’ or ‘No’