Likenesses of these forms of government and patterns of them, so to speak, may be found in families. For instance, the association of father and sons has the form of kingly rule; for the father cares for his children. This, also, is the reason why Homer addresses Zeus as father; for kingly government aims at being a paternal government. But in Persia the association of father and son is tyrannical; for fathers there use their sons as slaves. The association of master and slave is also tyrannical; for it is the interest of the master that is secured by it. But this seems to be a legitimate kind of tyranny, while the Persian kind seems to be wrong; for different beings require different kinds of government.