Hugo then classifies the sciences in the usual Aristotelian way, and shows that Christian theology is the end of all philosophy. The first part of _philosophia theorica_ is mathematics, which speculates as to the visible forms of visible things. The second is physics, which scrutinizes the invisible causes of visible things. The third, theology, alone contemplates invisible substances and their invisible natures. Herein is a certain progression; and the mind mounts to knowledge of the true. Through the visible forms of visible things, it comes to invisible causes of visible things; and through the invisible causes of visible things, it ascends to invisible substances, and to knowing their natures. This is the summit of philosophy and the perfection of truth. In this, as already said, the wise of this world were made foolish; because proceeding by the natural document alone, making account only of the elements and appearance of the world, they missed the instructive instances of Grace: which in spite of humble guise afford the clearer insight into truth. This is Hugo’s scheme of knowledge; it begins with _cogitatio_, then proceeds through _meditatio_ to _contemplatio_ of the creature world, and finally of the Creator. The arts and sciences, as well as the face of nature, afford a _simulacrum_ of the unseen Power; but all this knowledge by itself will not bring man to the perfect knowledge of God. For this he needs the _exemplaria_ of Grace, shown through the incarnation of the Word. Only by virtue of this added means, may man attain to perfect contemplation of the truth of God. That end and final summit is beyond reason’s reach; but the attainment of rational knowledge makes part of the path thither. Keen as was Hugo’s intellectual nature, his interest in reason was coupled with a deeper interest in that which reason might neither include nor understand. The intellect does not include the emotional and immediately desiderative elements of human nature; neither can it comprehend the infinite which is God; and Hugo drew toward God not only through his intellect, but likewise through his desiderative nature, with its yearnings of religious love. That love with him was rational, since its object satisfied his mind as far as his mind could comprehend it.