To leave the number of births unrestricted, as is done in most states, inevitably causes poverty among the citizens, and poverty produces crime and faction.
Nature does nothing without a purpose. In children may be observed the traces and seeds of what will one day be settled psychological habits, though psychologically a child hardly differs for the time being from an animal.
The generality of men are naturally apt to be swayed by fear rather than reverence, and to refrain from evil rather because of the punishment that it brings than because of its own foulness.
Hence both women and children must be educated with an eye to the constitution, if indeed it makes any difference to the virtue of a city-state that its children be virtuous, and its women too. And it must make a difference, since half the free population are women, and from children come those who participate in the constitution.
For imitation is natural to man from his infancy. Man differs from other animals particularly in this, that he is imitative, and acquires his rudiments of knowledge in this way; besides, the delight in it is universal.