the understanding, to incline to the true, to be dissatisfied with the
false, and in matters uncertain to withhold assent. What is the proof of
this? Imagine (persuade yourself), if you can, that it is now night. It
is not possible. Take away your persuasion that it is day. It is not
possible. Persuade yourself or take away your persuasion that the stars
are even in number. It is impossible. When then any man assents to that
which is false, be assured that he did not intend to assent to it as
false, for every soul is unwillingly deprived of the truth, as Plato
says; but the falsity seemed to him to be true. Well, in acts what have
we of the like kind as we have here truth or falsehood? We have the fit
and the not fit (duty and not duty), the profitable and the
unprofitable, that which is suitable to a person and that which is not,
and whatever is like these. Can then a man think that a thing is useful
to him and not choose it? He cannot. How says Medea?

"'Tis true I know what evil I shall do,
But passion overpowers the better counsel."

She thought that to indulge her passion and take vengeance on her
husband was more profitable than to spare her children. It was so; but
she was deceived. Show her plainly that she is deceived, and she will
not do it; but so long as you do not show it, what can she follow except
that which appears to herself (her opinion)? Nothing else. Why then are
you angry with the unhappy woman that she has been bewildered about the
most important things, and is become a viper instead of a human
creature? And why not, if it is possible, rather pity, as we pity the
blind and the lame, so those who are blinded and maimed in the faculties
which are supreme?

Whoever then clearly remembers this, that to man the measure of every