The next great advance was made by Abu Hudhayl Muhammad al-Allaf (d. _circa_ 226), a disciple of the second generation from Wasil. At his hands the doctrine of God’s qualities assumed a more definite form. Wasil had reduced God to a vague unity, a kind of eternal oneness. Abu Hudhayl taught that the qualities were not _in_ His essence, and thus separable from it, thinkable apart from it, but that they _were_ His essence. Thus, God was omnipotent by His omnipotence, but it _was_ His essence and not in His essence. He was omniscient by His omniscience and it _was_ His essence. Further, he held that these qualities must be either negations or relations. Nothing positive can be asserted of them, for that would mean that there was in God the complexity of subject and predicate, being and quality; and God is absolute Unity. This view the Muslim theologians regard as a close approximation to the Christian Trinity; for them, the persons of the Trinity have always been personified qualities, and such seems really to have been the view of John of Damascus. Further, God’s Will, according to Abu Hudhayl, as expressed in His Creative Word, did not necessarily exist in a subject (_fi mahall_, _in subiecto_). When God said, “Be!” creatively, there was no subject. Again, he endeavored—and in this he was followed by most of the Mu‘tazilites—to cut down the number of God’s attributes. His will, he said, was a form of His knowledge; He knew that there was good in an action, and that knowledge was His will.