Ibn Sīnā and those who agreed with him were led into contradictions, some of which al-Rāzī mentioned.

When their account of the contingent is subjected to close scrutiny, they retreat to affirming future possibility: an existing thing may cease to exist in the future, and a nonexistent entity may come into existence in the future. Thus, whatever admits of both existence and nonexistence can only be originated in time. This is the position of most rational thinkers.

Their discussions of metaphysics and of this supposedly eternal, beginningless contingent are utterly inconsistent, as Ibn Rushd and others have noted.

In their discussions of it in logic and elsewhere, however, they agreed with their predecessors—Aristotle and his followers—and all other rational thinkers. They explicitly stated that whatever can either exist or not exist must be originated in time, preceded by its own nonexistence. They divided the contingent into categories, all of which are originated in time, and made the necessary—that which necessarily exists and is eternal and beginningless—the contrasting category to the possible in the ordinary sense. They explicitly stated that what is eternal and beginningless cannot be described as contingent, admitting of both existence and nonexistence.

Among those who explicitly stated this were Ibn Sīnā and his followers when they discussed metaphysics