We, however, are considering the other supposition: that it is impossible for temporal events to arise without a temporally originated cause. On this supposition, the will must be present when the intended effect comes into existence, and there must be a will concurrent with that effect and necessarily entailing it. It is therefore impossible for there to have been, in pre-eternity, a will accompanied by its intended effect—whether that will encompassed everything proceeding from Him (1), or was (2) specific to only some of the effects produced. For its intended effect is something brought about by the Lord, and this will is a will to act. It is self-evident that something an agent wills to bring about cannot be beginningless and eternal—something that has always existed and will always exist. Rather, it can only be temporally originated after not having existed.

[Avicenna’s Disagreement with Aristotle and the Majority of Philosophers]

This is known by rational necessity to rational people generally. It is agreed upon by the intellectual authorities of all religious communities, Muslim and non-Muslim, and by the great majority of both ancient and later philosophers, including Aristotle and his followers. None disputed it except a small band of would-be philosophers. Some of them, such as Avicenna and others like him, held that something could be a produced, contingent effect while nevertheless being beginningless and eternal; and some additionally held that it could be an intended effect of the will.

The great majority of rational people, however, maintain that the falsity of both these positions is known by rational necessity. Even the defenders (3) of Aristotle and his followers—such as Averroes and others—rejected the claim of their fellow philosophers, such as Avicenna, that a contingent being could be beginningless and eternal. They explained that, in adopting this position, those philosophers had departed from Aristotle and his followers. The matter is indeed as they stated.