Having considered the existence and nature of God in Book One of On The Truth Of The Catholic Faith, St. Thomas, in Book Two, turns his attention to creation and creatures, God's freedom in creation, the nature of man, and particularly the unity of soul and body within man. The necessity for the study of creatures to know God better, to lead man to a likeness of the divine wisdom, to set aside errors, since errors about creatures lead men away from the truth of faith by being opposed to the true knowledge of God-is emphatically set forth by St. Thomas as essential to an understanding of the ultimate truth on the nature of creation. From this preliminary discussion, he then turns directly to a study of creation, treating of the subject matter under three main divisions the bringing forth of things into being, their distinction and order, and finally, the nature of creatures.