X. Besides this, no day is appointed for repayment of a benefit, as there is for borrowed money; consequently he who has not yet repaid a benefit may do so hereafter: for tell me, pray, within what time a man is to be declared ungrateful? The greatest benefits cannot be proved by evidence; they often lurk in the silent consciousness of two men only; are we to introduce the rule of not bestowing benefits without witnesses? Next, what punishment are we to appoint for the ungrateful? is there to be one only for all, though the benefits which they have received are different? or should the punishment be varying, greater or less according to the benefit which each has received? Are our valuations to be restricted to pecuniary fines? what are we to do, seeing that in some cases the benefit conferred is life, and things dearer than life? What punishment is to be assigned to ingratitude for these? One less than the benefit? That would be unjust. One equal to it; death? What could be more inhuman than to cause benefits to result in cruelty? XI. It may be argued, "Parents have certain privileges: these are regarded as exempt from the action of ordinary rules, and so also ought to be the case with other beneficent persons." Nay; mankind has assigned a peculiar sanctity to the position of parents, because it was advantageous that children should be reared, and people had to be tempted into undergoing the toil of doing so, because the issue of their experiment was doubtful. One cannot say to them, as one does to others who bestow benefits, "Choose the man to whom you give: you must only blame yourself if you are deceived; help the deserving." In rearing children nothing depends upon the judgment of those who rear them; it is a matter of hope: in order, therefore, that people may be more willing to embark upon this lottery, it was right that they should be given a certain authority; and since it is useful for youth to be governed, we have placed their parents in the position of domestic magistrates, under whose guardianship their lives may be ruled. Moreover, the position of parents differs from that of other benefactors, for their having given formerly to their children does not stand in the way of their giving now and hereafter; and also, there is no fear of their falsely asserting that they have given: with others one has to inquire not only whether they have received, but whether they have given; but the good deeds of parents are placed beyond doubt. In the next place, one benefit bestowed by parents is the same for all, and might be counted once for all; while the others which they bestow are of various kinds, unlike one to another, differing from one another by the widest possible intervals; they can therefore come under no regular rule, since it would be more just to leave them all unrewarded than to give the same reward to all.