The heart is the perfection of the whole organism. Therefore the principles of the power of perception and the souls ability to nourish itself must lie in the heart.
Now the goodness that we have to consider is clearly human goodness, since the good or happiness which we set out to seek was human good and human happiness. But human goodness means in our view excellence of soul, not excellence of body.
Every art and every inquiry, and similarly every action and pursuit, is thought to aim at some good; and for this reason the good has rightly been declared to be that at which all things aim.
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.