<p>Since the chief aim of this sacred science is to give the knowledge of God, not only as He is in Himself, but also as He is the Beginning of all things, and the End of all, especially of rational creatures, we shall treat first of God; secondly, of the rational creature's advance towards God; thirdly, of Christ, Who, as Man, is the way by which we tend to God.<br /><em>– Saint Thomas Aquinas</em></p>