that the word has an infinite number of meanings, obviously
reasoning would be impossible; for not to have one meaning is to
have no meaning, and if words have no meaning our reasoning with one
another, and indeed with ourselves, has been annihilated; for it is
impossible to think of anything if we do not think of one thing; but
if this is possible, one name might be assigned to this thing.)
Let it be assumed then, as was said at the beginning, that the
name has a meaning and has one meaning; it is impossible, then, that
'being a man' should mean precisely 'not being a man', if 'man' not
only signifies something about one subject but also has one
significance (for we do not identify 'having one significance' with
'signifying something about one subject', since on that assumption
even 'musical' and 'white' and 'man' would have had one
significance, so that all things would have been one; for they would
all have had the same significance).
And it will not be possible to be and not to be the same thing,
except in virtue of an ambiguity, just as if one whom we call 'man',
others were to call 'not-man'; but the point in question is not
this, whether the same thing can at the same time be and not be a
man in name, but whether it can in fact. Now if 'man' and 'not-man'
mean nothing different, obviously 'not being a man' will mean
nothing different from 'being a man'; so that 'being a man' will be
'not being a man'; for they will be one. For being one means
this-being related as 'raiment' and 'dress' are, if their definition
is one. And if 'being a man' and 'being a not-man' are to be one, they
must mean one thing. But it was shown earlier' that they mean
different things.-Therefore, if it is true to say of anything that
it is a man, it must be a two-footed animal (for this was what 'man'
meant); and if this is necessary, it is impossible that the same thing
should not at that time be a two-footed animal; for this is what
'being necessary' means-that it is impossible for the thing not to be.
It is, then, impossible that it should be at the same time true to say
the same thing is a man and is not a man.
The same account holds good with regard to 'not being a man',
for 'being a man' and 'being a not-man' mean different things, since
even 'being white' and 'being a man' are different; for the former
terms are much more different so that they must a fortiori mean
different things. And if any one says that 'white' means one and the
same thing as 'man', again we shall say the same as what was said
before, that it would follow that all things are one, and not only
opposites. But if this is impossible, then what we have maintained
will follow, if our opponent will only answer our question.
And if, when one asks the question simply, he adds the
contradictories, he is not answering the question. For there is
nothing to prevent the same thing from being both a man and white
and countless other things: but still, if one asks whether it is or is
not true to say that this is a man, our opponent must give an answer
which means one thing, and not add that 'it is also white and
large'. For, besides other reasons, it is impossible to enumerate
its accidental attributes, which are infinite in number; let him,
then, enumerate either all or none. Similarly, therefore, even if
the same thing is a thousand times a man and a not-man, he must not,
in answering the question whether this is a man, add that it is also
at the same time a not-man, unless he is bound to add also all the
other accidents, all that the subject is or is not; and if he does
this, he is not observing the rules of argument.
And in general those who say this do away with substance and
essence. For they must say that all attributes are accidents, and that
there is no such thing as 'being essentially a man' or 'an animal'.
For if there is to be any such thing as 'being essentially a man' this
will not be 'being a not-man' or 'not being a man' (yet these are
negations of it); for there was one thing which it meant, and this was
the substance of something. And denoting the substance of a thing
means that the essence of the thing is nothing else. But if its