In every case, the upshot of their doctrine is to deny a Necessary Existent that is distinct from contingent existence, to deny a Creator separate from His creatures, and to deny an Eternal Being apart from what is brought into being. This is precisely the creed of the Muʿaṭṭilah (those who negate the divine attributes), a topic discussed at length elsewhere.

Our aim here is simply to show that Ibn Sīnā’s procedure—and that of his followers—regarding the Necessary Existent does no more than assert the bare existence of something “necessary.” It never proves that this being is separate from the universe except by stripping Him of attributes, an approach that is invalid; even were it sound, it would still amount to nothing beyond affirming an undifferentiated, absolute existence. At best it establishes a concept in the mind, or an existence common to all beings, but it does not demonstrate an existence that is distinct from the contingent world.

Ibn Sīnā borrowed this line of argument from the Muʿtazilah. They had divided beings into originated and eternal, and, having established the reality of the eternal, he recast the division as necessary versus possible. His aim was to uphold the Necessary Existent without conceding that the world is created, treating the world’s existence as merely possible. In doing so he departed from the earlier philosophers, such as Aristotle and his followers, for whom what is “possible” can never actually exist. They did not divide existence into necessary and possible as Ibn Sīnā did; rather, they proved the First Cause through motion, claiming that the celestial sphere moves out of longing to resemble that First Cause. For them, the First Cause moves the heavens just as a beloved moves the lover—and their position is even more unsound than that of Ibn Sīnā.

The method adopted by Ibn Sīnā, his followers, and the Muʿtazilah can, moreover, be recast in other forms. One might, for instance, say that existence is divided into what is self-sufficient and what is in need of