XVI. These same adversaries of ours admit that they are grateful,
yet not because it is honourable, but because it is profitable to
be so. This can be proved to be untrue all the more easily, because
it can be established by the same arguments by which we have
established that to bestow a benefit is desirable for its own sake.
All our arguments start from this settled point, that honour is
pursued for no reason except because it is honour. Now, who will
venture to raise the question whether it be honourable to be
grateful? who does not loathe the ungrateful man, useless as he is
even to himself? How do you feel when any one is spoken of as being
ungrateful for great benefits conferred upon him by a friend? Is it
as though he had done something base, or had merely neglected to do
something useful and likely to be profitable to himself? I imagine
that you think him a bad man, and one who deserves punishment, not
one who needs a guardian; and this would not be the case, unless
gratitude were desirable in itself and honourable. Other qualities,
it may be, manifest their importance less clearly, and require an
explanation to prove whether they be honourable or no; this is
openly proved to be so in the sight of all, and is too beautiful
for anything to obscure or dim its glory. What is more
praiseworthy, upon what are all men more universally agreed, than
to return gratitude for good offices?

XVII. Pray tell me, what is it that urges us to do so? Is it
profit? Why, unless a man despises profit, he is not grateful. Is
it ambition? why, what is there to boast of in having paid what you
owe? Is it fear? The ungrateful man feels none, for against this
one crime we have provided no law, as though nature had taken
sufficient precautions against it. Just as there is no law which