Aristotle, Politics

[1254b] [1] 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 unnatural 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 rules the appetites with that of a statesman or a king 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 the 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. Again, 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 as a whole; therefore all men that differ as widely as the soul does from the body and the human being from the lower animal （and this is the condition of those whose function is the use of the body and from whom this is the best that is forthcoming） these are by nature slaves, for whom to be governed by this kind of authority [20] is advantageous, inasmuch as it is advantageous to the subject things already mentioned. For he is by nature a slave who is capable of belonging to another （and that is why he does so belong）, and who participates in reason so far as to apprehend it but not to possess it; for the animals other than man are subservient not to reason, by apprehending it, but to feelings. And also the usefulness of slaves diverges little from that of animals; bodily service for the necessities of life is forthcoming from both, from slaves and from domestic animals alike. The intention of nature therefore is to make the bodies also of freemen and of slaves different—the latter strong for necessary service, the former erect and unserviceable for such occupations, but serviceable for a life of citizenship （and that again divides into the employments of war and those of peace）; but as a matter of fact often the very opposite comes about—some persons have the bodies of free men and others the souls; since this is certainly clear, that if persons were born as distinguished only in body as are the statues of the gods, everyone would say that those who were inferior deserved to be these men's slaves. And if this is true in the case of the body, there is far juster reason for this rule being laid down in the case of the soul; but beauty of soul is not so easy to see as beauty of body.