In touching on S. Thomas's commentary on the "Sentences," the influence of Alexander Hales must not be forgotten, but he far eclipsed the Minorite in his proofs of the non-eternity of the world--a question of momentous importance in the Middle Ages, as well as in his discussion of the possibility and fitness of the Incarnation. Thomas carried his teaching on Grace to such perfection that in the Middle Ages it was always received as a standard authority. If judged by its bulk, this "Commentary" would seem sufficient to have occupied a life. It fills over 1250 pages of the large quarto Parma edition, printed in double columns. It is a monument of ceaseless labour, great skill, and patient thought. The work of the Lombard is a confusion compared with the lucid style and admirable arrangement of the saint. In place of the crabbed inverted language of Peter, we have the simple, logical, direct use of words, which go straight to the point, and express the complete idea. He has these weighty words on the subject of theology, "Since the end of all philosophy is contained within the end of theology, and is subservient to it, theology ought to command all other sciences, and turn to its use those things which they treat of." He adds, "The more sublime knowledge is, so much greater is its unity, and so much wider the circle of its expansion, whence the Divine intellect, which is the most sublime of all, by the light, which is God Himself, possesses a distinct knowledge of all things." He also shows how the intellect becomes illuminated when led by faith, illustrating the motto of the monastic school, "Nisi credideritis, non intelligetis." And he shows that theology is _deduction_, and philosophy _induction_; and that the basis of theology must be authority, _i.e._, a Revelation.