20. But the converse must also be observed. For in friendship and relationship, just as those who possess any superiority must put themselves on an equal footing with those who are less fortunate, so these latter must not be annoyed at being surpassed in genius, fortune, or rank. But most people of that sort are forever either grumbling at something, or harping on their claims; and especially if they consider that they have services of their own to allege involving zeal and friendship and some trouble to themselves. People who are always bringing up their services are a nuisance. The recipient ought to remember them; the performer should never mention them. In the case of friends, then, as the superior are bound to descend, so are they bound in a certain sense to raise those below them. For there are people who make their friendship disagreeable by imagining themselves undervalued. This generally happens only to those who think that they deserve to be so; and they ought to be shewn by deeds as well as by words the groundlessness of their opinion. Now the measure of your benefits should be in the first place your own power to bestow, and in the second place the capacity to bear them on the part of him on whom you are bestowing affection and help. For, however great your personal prestige may be, you cannot raise all your friends to the highest offices of the State. For instance, Scipio was able to make Publius Rupilius consul, but not his brother Lucius. But granting that you can give anyone anything you choose, you must have a care that it does not prove to be beyond his powers. As a general rule, we must wait to make up our mind about friendships till men's characters and years have arrived at their full strength and development. People must not, for instance, regard as fast friends all whom in their youthful enthusiasm for hunting or football they liked for having the same tastes. By that rule, if it were a mere question of time, no one would have such claims on our affections as nurses and slave-tutors. Not that they are to be neglected, but they stand on a different ground. It is only these mature friendships that can be permanent. For difference of character leads to difference of aims, and the result of such diversity is to estrange friends. The sole reason, for instance, which prevents good men from making friends with bad, or bad with good, is that the divergence of their characters and aims is the greatest possible.