The purpose of this chapter is to argue that at least some slavery must be natural, because the relationship of master and slave conforms to a broad pattern found universally in nature in the widest sense: better/worse, male/female, man/beast, mind/body, rational/irrational, ruler/ruled. Such a pattern makes obvious sense to Aristotle, who justifies it teleologically by its beneficial results: to be ruled is to the slave’s advantage, and is to that extent just. In the final paragraph some admitted exceptions to the pattern do not make him doubt its essential validity: presumably he finds it sufficient for the purposes of his argument that nature achieves her ends only ‘for the most part’ (as he often concedes in other contexts).
Aristotle’s view that slavery is expedient both for master and for slave has attracted a great deal of criticism, much of it obvious and justified. Is there anything to be said in its favour? It clearly relies on the assumption that most masters are rational and most slaves are not; or rather, that men fall readily into two classes, rational and irrational, and that the former should rule the latter. With large qualifications, it is at least arguable that such rule ought to be enforced, and is in fact enforced, in society at large. One does not have to defend the particular institutional form of such rule that Aristotle seeks to justify (ancient slavery). If (and it is a big if) we grant his asumptions, the master/slave relationship does indeed seem analogous in some respects to certain other relationships which are presumably desirable (e.g. mind over body, man over beast). But this is of course to defend not slavery as such, but only in so far as it embodies the rule of rational over irrational. In so far as it does not, even Aristotle would hesitate to defend it, as his next chapter makes clear.
I conclude with two points that are forgotten easily and often: (a) The fact that slavery is a dirty word nowadays should not trick us into believing that ancient Greek slavery was invariably harsh and therefore not ‘expedient’ for slaves: much depended on the masters’ attitudes, which in the nature of the case varied widely. (b) The distinction between slave and free was much sharper in point of legal and political status than in social life and economics, where there was some overlap between the poorer free men and the better-off slaves.
1254a17 But whether anyone does in fact by nature answer to this description, and whether or not it is a just and a better thing for one man to be a slave to another, or whether all slavery is contrary to nature – these are the questions which must be considered next. Neither theoretical discussion nor empirical observation presents any difficulty. That one should command and another obey is both necessary and expedient. Indeed some things are so divided right from birth, some to rule, some to be ruled. There are many different forms of this ruler-ruled relationship, and the quality of the rule depends primarily on the quality of the subjects, rule over man being better than rule over animals; for that which is produced by better men is a better piece of work; and the ruler-ruled relationship is itself a product created by the men involved in it.
1254a28 For wherever there is a combination of elements, continuous or discontinuous,1 and a common unity is the result, in all such cases the ruler-ruled relationship appears. It appears notably in living creatures as a consequence of their whole nature (and it can exist also where there is no life, as dominance in a musical scale,2 but that is hardly relevant here). The living creature consists in the first place of mind and body, and of these the former is ruler by nature, the latter ruled. Now we must always look for nature’s own norm in things whose condition is according to nature, and not base our observations on degenerate forms. We must therefore in this connexion consider the man who is in good condition mentally and physically, one in whom the rule of mind over body is conspicuous – because the bad and unnatural condition of a permanently or temporarily depraved person will often give the impression that his body is ruling over his soul.
1254b2 However that may be, it is, as I say, within living creatures that we first find it possible to see both the rule of a master and that of a statesman.3 The rule of soul over body is like a master’s rule, while the rule of intelligence over desire is like a statesman’s or a king’s.4 In these relationships it is clear that it is both natural and expedient for the body to be ruled by the soul, and for the emotional part of our natures to be ruled by the mind, the part which possesses reason. The reverse, or even parity, would be fatal all round. This is also true as between man and the other animals; for tame animals are by nature better than wild, and it is better for them all to be ruled by men, because it secures their safety. Again, as between male and female the former is by nature superior and ruler, the latter inferior and subject. And this must hold good of mankind in general.
1254b16 Therefore whenever there is the same wide discrepancy between human beings as there is between soul and body or between man and beast, then those whose condition is such that their function is the use of their bodies and nothing better can be expected of them, those, I say, are slaves by nature. It is better for them, just as in the cases mentioned, to be ruled thus.5 For the ‘slave by nature’ is he that can and therefore does belong to another, and he that participates in reason so far as to recognize6 it but not so as to possess it (whereas the other7 animals obey not reason but emotions). The use made of slaves hardly differs at all from that of tame animals: they both help with their bodies to supply our essential needs. It is, then, nature’s purpose to make the bodies of free men to differ from those of slaves, the latter strong enough to be used for necessary tasks, the former erect and useless for that kind of work, but well suited for the life of a citizen of a state8, a life which is in turn divided between the requirements of war and peace.
1254b32 But the opposite often occurs: people who have the right kind of bodily physique for free men, but not the soul, others who have the right soul but not the body. This much is clear: suppose that there were men whose mere bodily physique showed the same superiority as is shown by the statues of gods, then all would agree that the rest of mankind would deserve to be their slaves. And if this is true in relation to physical superiority, the distinction would be even more justly made in respect of superiority of soul; but it is much more difficult to see beauty of soul than it is to see beauty of body. It is clear then that by nature some are free, others slaves, and that for these it is both just and expedient that they should serve as slaves.