Yet they imagined that these mental concepts had an objective existence outside the mind, and that is a mistake—one that is treated at length elsewhere.

Since everything apart from God is, by its very essence, dependent on Him, and since origination (ḥudūth) and contingency (imkān) both entail and point to that dependence, the question arises: can contingency be conceived without origination? This is a point of contention. The great majority of rational people—early and late alike—the adherents of all the revealed religions, and the leading philosophers such as Aristotle and his followers, hold that contingency and origination are inseparable. Ibn Sīnā and those who agree with him diverged from this view, claiming that a contingent being could be eternal, without beginning, and necessary through something other than itself.

What concerns us here is Ibn Sīnā’s assertion that the causes responsible for a contingent being’s existence—considered insofar as that existence is predicated together with the effect—must remain causes for as long as the effect endures; likewise, for as long as the cause endures, its effect endures.

He said:

“Once these premises have been clarified, the existence of a Necessary Existent becomes unavoidable. When contingent beings exist and their existence is established, there must be causes that sustain that existence. Those causes may be the very same causes of origination, provided they remain along with the originated entity, or they may be other causes that accompany originated things. In any event, they must inevitably terminate in a Necessary Existent, for we have already shown that causal chains cannot extend to infinity, nor can they form a circle.”