successive, each of them would necessarily have come into being. In that case, there are only two possibilities: either something among them existed from eternity, or none of them existed from eternity.

If the former were the case, it would be impossible, because what is eternal is not preceded by nonexistence, whereas what comes into being is preceded by nonexistence. Thus, if something among them existed from eternity, it would necessarily be preceded by nonexistence because it came into being, yet would not have come into being because it was eternal. If the latter were the case, then the totality of causes and effects would necessarily be preceded by nonexistence, since none of them existed from eternity. It follows that they must have a beginning and an endpoint that does not depend on anything else preceding it. This is what was to be proved.”

[Ibn Taymiyyah’s Commentary]

I say:

This argument is the third argument mentioned by al-Rāzī, where he said:

“Either some of these motions occurred from eternity, or none did. If none of these motions occurred from eternity, then the totality of these motions and events must have a beginning and a first member. This is what was to be proved.

If some of these motions occurred from eternity, then, if that motion occurring from eternity was not preceded by another, it would be the first motion. This is what was to be proved. If it was preceded by another, it would follow that what is first was preceded by something else, which is impossible.”