Aristotle, Nicomachean Ethics
H. Rackham, Ed.

or ought one to ransom one's own father? for it might be thought to be a man's duty to ransom his father even before himself. 2. [5] As a general rule then, as has been said, one ought to pay back a debt, but if the balance of nobility or urgency is on the side of employing the money for a gift, then one ought to decide in favor of the gift. For （b） there are occasions when it would be actually unfair to return the original service; as for instance when A has done B a service knowing him to be a good man, and B is called upon to return the service to A whom he believes to be a bad man. For even when A has lent B a loan, B is not always bound to lend A a loan in turn: A may have lent money to B, who is an honest man, expecting to get his money back, while B would have no hope of recovering from A, who is a rascal. If A is really a rascal, the return he asks for is not a fair one; and even if A is not a rascal, but people think¹ he is, it would not be deemed unreasonable for B to refuse. 2. [6]

Hence, as has been frequently remarked already,² discussions about our emotions and actions only admit of such degree of definiteness as belongs to the matters with which they deal. 2. [7]

It is quite clear therefore that all people have not the same claim upon us, and that even a father's claim is not unlimited, just as Zeus does not have all the sacrifices. Since the claims of parents and brothers, comrades and benefactors, are different, we ought to render to each that which is proper and suitable to each. This is in fact the principle on which men are observed to act. They invite their relatives to a wedding, because they are members of the family,