sick man should be more anxious about his health than one who is
healthy; for he who has opinions is, in comparison with the man who
knows, not in a healthy state as far as the truth is concerned.
Again, however much all things may be 'so and not so', still there
is a more and a less in the nature of things; for we should not say
that two and three are equally even, nor is he who thinks four
things are five equally wrong with him who thinks they are a thousand.
If then they are not equally wrong, obviously one is less wrong and
therefore more right. If then that which has more of any quality is
nearer the norm, there must be some truth to which the more true is
nearer. And even if there is not, still there is already something
better founded and liker the truth, and we shall have got rid of the
unqualified doctrine which would prevent us from determining
anything in our thought.
From the same opinion proceeds the doctrine of Protagoras, and
both doctrines must be alike true or alike untrue. For on the one
hand, if all opinions and appearances are true, all statements must be
at the same time true and false. For many men hold beliefs in which
they conflict with one another, and think those mistaken who have
not the same opinions as themselves; so that the same thing must
both be and not be. And on the other hand, if this is so, all opinions
must be true; for those who are mistaken and those who are right are
opposed to one another in their opinions; if, then, reality is such as
the view in question supposes, all will be right in their beliefs.
Evidently, then, both doctrines proceed from the same way of
thinking. But the same method of discussion must not be used with
all opponents; for some need persuasion, and others compulsion.
Those who have been driven to this position by difficulties in their
thinking can easily be cured of their ignorance; for it is not their
expressed argument but their thought that one has to meet. But those
who argue for the sake of argument can be cured only by refuting the
argument as expressed in speech and in words.
Those who really feel the difficulties have been led to this
opinion by observation of the sensible world. (1) They think that
contradictories or contraries are true at the same time, because
they see contraries coming into existence out of the same thing. If,
then, that which is not cannot come to be, the thing must have existed
before as both contraries alike, as Anaxagoras says all is mixed in
all, and Democritus too; for he says the void and the full exist alike
in every part, and yet one of these is being, and the other non-being.
To those, then, whose belief rests on these grounds, we shall say that
in a sense they speak rightly and in a sense they err. For 'that which
is' has two meanings, so that in some sense a thing can come to be out
of that which is not, while in some sense it cannot, and the same
thing can at the same time be in being and not in being-but not in the
same respect. For the same thing can be potentially at the same time
two contraries, but it cannot actually. And again we shall ask them to
believe that among existing things there is also another kind of
substance to which neither movement nor destruction nor generation
at all belongs.
And (2) similarly some have inferred from observation of the
sensible world the truth of appearances. For they think that the truth
should not be determined by the large or small number of those who
hold a belief, and that the same thing is thought sweet by some when
they taste it, and bitter by others, so that if all were ill or all
were mad, and only two or three were well or sane, these would be
thought ill and mad, and not the others.
And again, they say that many of the other animals receive
impressions contrary to ours; and that even to the senses of each
individual, things do not always seem the same. Which, then, of
these impressions are true and which are false is not obvious; for the
one set is no more true than the other, but both are alike. And this