The Complete Aristotle (eng.)

times of danger or similar need. Now if the
friendship is one that aims at utility, surely the advantage to the
receiver is the measure. For it is he that asks for the service,
and the other man helps him on the assumption that he will receive
the equivalent; so the assistance has been precisely as great as
the advantage to the receiver, and therefore he must return as much
as he has received, or even more (for that would be nobler). In
friendships based on virtue on the other hand, complaints do not
arise, but the purpose of the doer is a sort of measure; for in
purpose lies the essential element of virtue and character.
<
    div class="section" title="14">
14
    Differences arise also in friendships based on superiority; for
each expects to get more out of them, but when this happens the
friendship is dissolved. Not only does the better man think he
ought to get more, since more should be assigned to a good man, but
the more useful similarly expects this; they say a useless man
should not get as much as they should, since it becomes an act of
public service and not a friendship if the proceeds of the
friendship do not answer to the worth of the benefits conferred.
For they think that, as in a commercial partnership those who put
more in get more out, so it should be in friendship. But the man
who is in a state of need and inferiority makes the opposite claim;
they think it is the part of a good friend to help those who are in
need; what, they say, is the use of being the friend of a good man
or a powerful man, if one is to get nothing out of it?
    At all events it seems that each party is justified in his
claim, and that each should get more out of the friendship than the
other-not more of the same thing, however, but the superior more
honour and the inferior more gain; for honour is the prize of
virtue and of beneficence, while gain is the assistance required by
inferiority.
    It seems to be so in constitutional arrangements also; the man
who contributes nothing good to the common stock is not honoured;
for what belongs to the public is given to the man who benefits the
public, and honour does belong to the public. It is not possible to
get wealth from the common stock and at the same time honour. For
no one puts up with the smaller share in all things; therefore to
the man who loses in wealth they assign honour and to the man who
is willing to be paid, wealth, since the proportion to merit
equalizes the parties and preserves the friendship, as we have
said. This then is also the way in which we should associate with
unequals; the man who is benefited in respect of wealth or virtue
must give honour in return, repaying what he can. For friendship
asks a man to do what he can, not what is proportional to the
merits of the case; since that cannot always be done, e.g. in
honours paid to the gods or to parents; for no one could ever
return to them the equivalent of what he gets, but the man who
serves them to the utmost of his power is thought to be a good man.
This is why it would not seem open to a man to disown his father
(though a father may disown his son); being in debt, he should
repay, but there is nothing by doing which a son will have done the
equivalent of what he has received, so that he is always in debt.
But creditors can remit a debt; and a father can therefore do so
too. At the same time it is thought that presumably no one would
repudiate a son who was not far gone in wickedness; for apart from
the natural friendship of father and son it is human nature not to
reject a son’s assistance. But the son, if he is wicked, will
naturally avoid aiding his father, or not be zealous about it; for
most people wish to get benefits, but avoid doing them, as a thing
unprofitable.-So much for these questions.

Nicomachean Ethics, Book IX
    Translated by W. D. Ross
<
    div class="section" title="1">
1
    In all friendships between dissimilars it is, as we have said,
proportion that equalizes the parties and preserves the friendship;
e.g. in the political form of friendship the shoemaker gets a
return for his shoes in proportion to his worth, and the weaver and
all other craftsmen do the same. Now here a common measure has been
provided in the form of money, and therefore everything is referred
to this and measured by this; but in the friendship of lovers
sometimes the lover complains that his excess of love is not met by
love in return though perhaps there is nothing lovable about him),
while often the beloved complains that