Any one above or below those ages who partakes in the hymeneals shall be guilty of impiety; also every one who forms a marriage connexion at other times without the consent of the rulers.

This latter regulation applies to those who are within the specified ages, after which they may range at will, provided they avoid the prohibited degrees of parents and children, or of brothers and sisters, which last, however, are not absolutely prohibited, if a dispensation be procured.

'But how shall we know the degrees of affinity, when all things are common ?' The answer is, that brothers and sisters are all such as are born seven or nine months after the espousals, and their parents those who are then espoused, and every one will have many children and every child many parents.
Socrates proceeds: I have now to prove that this scheme is advantageous and also consistent with our entire polity.

The greatest good of a State is unity; the greatest evil, discord and distraction.

And there will be unity where there are no private pleasures or pains or interests--where if one member suffers all the members suffer, if one citizen is touched all are quickly sensitive; and the least hurt to the little finger of the State runs through the whole body and vibrates to the soul.