Aristotle, Nicomachean Ethics
H. Rackham, Ed.

and becomes a tyrant; but the function of a ruler is to be the guardian of justice, and if of justice, then of equality. [6] A just ruler seems to make nothing out of his office; for he does not allot to himself a larger share of things generally good, unless it be proportionate to his merits; so that he labors for others, which accounts for the saying mentioned above,¹ that ‘Justice is the good of others.’ [7] Consequently some recompense has to be given him, in the shape of honor and dignity. It is those whom such rewards do not satisfy who make themselves tyrants. [8]

Justice between master and slave and between father and child is not the same as absolute and political justice, but only analogous to them. For there is no such thing as injustice in the absolute sense towards what is one's own; and a chattel,² or a child till it reaches a certain age and becomes independent, is, as it were, a part of oneself, and no one chooses to harm himself; [9] hence there can be no injustice towards them, and therefore nothing just or unjust in the political sense. For these, as we saw, are embodied in law, and exist between persons whose relations are naturally regulated by law, that is, persons who share equally in ruling and being ruled. Hence Justice exists in a fuller degree between husband and wife than between father and children, or master and slaves; in fact, justice between husband and wife is Domestic Justice in the real sense, though this too is different from Political Justice.7.

Political Justice is of two kinds, one natural, the other conventional. A rule of justice is natural that has the same validity everywhere,