Ibn Rushd and the other philosophers of his stripe follow the path of the ancients in this matter. Ibn Sīnā, however, abandoned that course for what he had gleaned from the mutakallimūn, adopting their division of existence into the Necessary and the Possible just as they divide it into the Eternal and the originated. He then described the properties of the Necessary Existent, some of which are sound while others are erroneous, for the only necessity established by proof is that He exists in and of Himself and is independent of any cause. Ibn Sīnā nonetheless loaded the term with ideas for which no evidence exists—such as the denial of divine attributes and similar claims.

He derived this from Muʿtazilite discourse on eternality; once they had affirmed an eternal entity and held that eternality entails the negation of attributes, they treated the existence he posited as analogous to the eternality they posited, even though neither concept substantiates the aim of either faction.

Ibn Sīnā employed a second method to prove the Necessary Existent, which he set out in his book al-Najāt. This proof is founded on the notion of origination (ḥudūth), where he says: “A concluding section on …”