Didascalicon, Book VI: how Scripture is to be read
Chapter V. On tropology and morality
Of tropology I shall say nothing else at present than what was said above, except that the signification of things rather than of words seems to pertain to it. For in it is natural justice, from which the discipline of our morals, that is positive justice, is born. By contemplating what God has done, we recognize what we ought to do. All nature speaks of God. All nature teaches man. All nature brings forth reason, and nothing in the universe is barren.