Slavery -- natural or conventional?
Aristole's theory of slavery is found in Book I, Chapters iii through vii of the Politics. and in Book VII of the Nicomachean Ethics
Aristotle raises the question of whether slavery is natural or conventional. He asserts that the former is the case. So, Aristotle's theory of slavery holds that some people are naturally slaves and others are naturally masters. Thus he says:
But is there any one thus intended by nature to be a slave, and for whom such a condition is expedient and right, or rather is not all slavery a violation of nature?
There is no difficulty in answering this question, on grounds both of reason and of fact. For that some should rule and others be ruled is a thing not only necessary, but expedient; from the hour of their birth, some are marked out for subjection, others for rule.
This suggests that anyone who is ruled must be a slave, which does not seem at all right. Still, given that this is so he must state what characteristics a natural slave must have -- so that he or she can be recognized as such a being. Who is marked out for subjugation, and who for rule? This is where the concept of "barbarian" shows up in Aristotle's account. Aristotle says:
But among barbarians no distinction is made between women and slaves, because there is no natural ruler among them: they are a community of slaves, male and female. Wherefore the poets say, It is meet that Hellenes should rule over barbarians;
as if they thought that the barbarian and the slave were by nature one. So men rule naturally over women, and Greeks over barbarians! But what is it which makes a barbarian a slave? Here is what Aristotle says:
Where then there is such a difference as that between soul and body, or between men and animals (as in the case of those whose business is to use their body, and who can do nothing better), the lower sort are by nature slaves, and it is better for...