ang on! What did you mean earlier, Socrates, about the Guardians having wives and children in common? (Part 4) Can we get this sorted out before we go any further? ( in fact they don't get back on to bad communities until Part 9).
Women
The only difference between men and women is biological - men beget children and women bear them. Both sexes can thus do the same jobs - although men will usually be better at them! Thus they should have the same education and the same opportunities. These ideas weren't unique to Plato - Aristophanes had already mocked them in his comedy Assemblywomen.
Children
More details about arrangements for children - the family, as we already know, is to be abolished for the Guardians. There's some rather unclear information about promotion and demotion of children born into the wrong class - and also about infanticide. The intention is eugenic - as with farm animals - to produce the best possible offspring. This section concludes with some more remarks about the ideal polis that they've created - the best state is one which most nearly resembles an individual - as many people as possible will use the expressions "mine" and "not mine" about the same things.
War
Logically, therefore men and women will both go to war - and children must be familiarized with it it. War is thus seen as a wholly natural part of human activity - but it should be employed wherever possible against non-Greeks (barbaroi). Greeks are natural 'friends' as barbaroi are natural enemies. If Greeks do fight Greeks there should be rules to avoid uncivilized behaviour.