is a ruling principle, as in the case of a musical scale.^a However, this matter perhaps belongs to an investigation10 lying somewhat outside our subject. But in the first place an animal consists of soul and body, of which the former is by nature the ruling and the latter the subject factor. And to discover what is natural we must study it preferably in things that are in a natural state, and not in specimens that are degenerate. Hence in studying man we must consider a man that is in the best possible condition in regard to both body and soul, and in him the principle stated will clearly appear,—since in those that are bad or in a bad condition it might be thought that the body often rules the soul because of its vicious and unnatural11 condition. But to resume—it is in a living creature, as we say, that it is first possible to discern the rule both of master and of statesman: the soul rules the body with the sway of a master, the intelligence the appetites with constitutional or royal rule; and in these examples it is manifest that it is natural and expedient for the body to be governed by the soul and for the emotional part to be governed by the intellect, the part possessing reason, whereas for the two parties to be on an equal footing or in the12 contrary positions is harmful in all cases. Again, the same holds good between man and the other animals: tame animals are superior in their nature to wild animals, yet for all the former it is advantageous to be ruled by man, since this gives them security. Also, as between the sexes, the male is by nature superior and the female inferior, the male ruler and the female subject. And the same must also necessarily apply in the case of mankind generally;13 therefore all men that differ as widely as the soul