But most of all when thou blamest a man as faithless or ungrateful, turn to thyself.
For the fault is manifestly thy own, whether thou didst trust that a man who had such a disposition would keep his promise, or when conferring thy kindness thou didst not confer it absolutely, nor yet in such way as to have received from thy very act all the profit.
For what more dost thou want when thou hast done a man a service? Art thou not content that thou hast done something conformable to thy nature, and dost thou seek to be paid for it? Just as if the eye demanded a recompense for seeing, or the feet for walking.
For as these members are formed for a particular purpose, and by working according to their several constitutions obtain what is their own; so also as man is formed by nature to acts of benevolence, when he has done anything benevolent or in any other way conducive to the common interest, he has acted conformably to his constitution, and he gets what is his own.