1. Male and female are ‘incapable of existing without each other’ not as individuals but as members of a species, over a period of many generations. Note the contrast between instinctive nature (phusis) and rational and purposive choice (prohairesis); on the latter, see Nicomachean Ethics III ii.

2. Evidently a knife capable of more than one mode of cutting, and not perfectly adapted to any one of them.

3. I.e of marriage.

4. Somewhat confusingly, Aristotle uses ‘slave’ both in a literal and in a metaphorical sense. In non-Greek societies a woman and a slave are ‘in the same position’ in that their de facto rulers (husband and master respectively) have not the wisdom and the rationality nature demands in a ‘natural’ ruler: authority is exercised by persons who are in point of fitness for rule no better than slaves. The ‘slave’ husband makes a ‘slave’ of his wife.

5. Euripides, Iphigeneia in Aulis 1400.