The study of thought and of the natures of all things.
Psychology/
Christian Anthropology
The study of man's nature, of his capacities, his interior life, the relationship between his flesh, or animal nature, and his spiritual center where God would be at home.
a curriculum based on the principle of the Incarnation:
Music
Perhaps the most unifying of all disciplines: the union of the harmony in sound, perfection in mathematics, poetry in language, and beauty in the human voice, which was made for the expression of love. A spiritually inspired (and theologically accurate) hymn to the Creator partakes of even greater unities. Choral singing may even contribute to civics!
There are a thousand other sub-disciplines and cross-disciplines. They are not less important for not being listed, for each represents a unique vocation of engagement to which one may be called in the manifold plan of God. But these are the foundations, essential to a full Christian engagement with the world. Each represents a specific aspect of the formation of the interior life.