into two persons are innumerable; we are wont to say, "Let me
converse with myself," and, "I will give myself a twitch of the
ear;" [Footnote: See book iv. ch. xxxvi.] and if it be true that
one can do so, then a man ought to be grateful to himself, just as
he is angry with himself; as he blames himself, SO he ought to
praise himself; since he can impoverish himself, he can also enrich
himself. Injuries and benefits are the converse of one another: if
we say of a man, 'he has done himself an injury,' we can also say
'he has bestowed upon himself a benefit?'

VIII. It is natural that a man should first incur an obligation,
and then that he should return gratitude for it; a debtor cannot
exist without a creditor, any more than a husband without a wife,
or a son without a father; someone must give in order that some one
may receive. Just as no one carries himself, although he moves his
body and transports it from place to place; as no one, though he
may have made a speech in his own defence, is said to have stood by
himself, or erects a statue to himself as his own patron; as no
sick man, when by his own care he has regained his health, asks
himself for a fee; so in no transaction, even when a man does what
is useful to himself, need he return thanks to himself, because
there is no one to whom he can return them. Though I grant that a
man can bestow a benefit upon himself, yet at the same time that he
gives it, he also receives it; though I grant that a man may
receive a benefit from himself, yet he receives it at the same time
that he gives it. The exchange takes place within doors, as they
say, and the transfer is made at once, as though the debt were a
fictitious one; for he who gives is not a different person to he
who receives, but one and the same. The word "to owe" has no
meaning except as between two persons; how then can it apply to one