This is deposited in books nowadays, and from these our children can learn it better than from elsewhere. But since there is need to do this, they have to know grammar. So this subject must be added to the two already mentioned for the children to be endowed with. But I say that beyond the need the soul has of these three things to arrive at perfection, they are additionally very useful for many things, both public and private, since painting can serve for numerous important designs for the city and for each private individual. There is need for grammar on many occasions both special and ordinary, as in the development of the laws, in announcements through letters, as well as others.
Music equally is very useful to excite, to calm, and to create longing in our soul.
But since the mean is always to be preferred above the extremes, since virtue is located in it, it would be better for the children first to become habituated to the Dorian, or in its stead to the Lombard which stands in the middle of all, to establish the soul in this middle state. Beyond this, since happiness is our highest good and every good causes gaiety and joy in us, so happiness does not keep us in sorrow and sadness, spirited and joyous.