Augustine of Hippo, Confessions XIII.16: That No One But the Unchangeable Light Knows Himself

19. For altogether as Thou art, Thou only knowest, Who art unchangeably, and knowest unchangeably, and willest unchangeably. And Thy Essence Knoweth and Willeth unchangeably; and Thy Knowledge Is, and Willeth unchangeably; and Thy Will Is, and Knoweth unchangeably. Nor doth it appear just to Thee, that as the Unchangeable Light knoweth Itself, so should It be known by that which is enlightened and changeable. Therefore unto Thee is my soul as “land where no water is,” because as it cannot of itself enlighten itself, so it cannot of itself satisfy itself. For so is the fountain of life with Thee, like as in Thy light we shall see light.