sharpness of our wits, and engross, our attention; so also these
questions, which seem subtle and tricky, prevent our intellects
becoming careless and lazy, for they ought at one time to have a
field given them to level, in order that they may wander about it,
and at another to have some dark and rough passage thrown in their
way for them to creep through, and make their way with caution. It
is said by our opponent that no one is ungrateful; and this is
supported by the following arguments: "A benefit is that which does
good; but, as you Stoics say, no one can do good to a bad man;
therefore, a bad man does not receive a benefit. (If he does not
receive it, he need not return it; therefore, no bad man is
ungrateful.) Furthermore, a benefit is an honourable and
commendable thing. No honourable or commendable thing can find any
place with a bad man; therefore, neither can a benefit. If he
cannot receive one, he need not repay one; therefore, he does not
become ungrateful. Moreover, as you say, a good man does everything
rightly; if he does everything rightly, he cannot be ungrateful. A
good man returns a benefit, a bad man does not receive one. If this
be so, no man, good or bad, can be ungrateful. Therefore, there is
no such thing in nature as an ungrateful man: the word is
meaningless." We Stoics have only one kind of good, that which is
honourable. This cannot come to a bad man, for he would cease to be
bad if virtue entered into him; but as long as he is bad, no one
can bestow a benefit upon him, because good and bad are contraries,
and cannot exist together. Therefore, no one can do good to such a
man, because whatever he receives is corrupted by his vicious way
of using it. Just as the stomach, when disordered by disease and
secreting bile, changes all the food which it receives, and turns
every kind of sustenance into a source of pain, so whatever you
entrust to an ill-regulated mind becomes to it a burden, an