If it is said that they necessarily exist in themselves, even though events subsist in them, then your claim that events cannot subsist in a necessarily existent or beginningless being is invalid.

If you say that they are effects produced by something other than themselves, then consider that which necessitates their existence. If it is a complete cause, none of its effects can arise later than it does. Motions and events therefore cannot proceed from it, and the events we observe must depend upon another necessarily existent being. The same argument applies to this being as to the first.

If it is not a complete cause, then anything whose occurrence is delayed must depend upon a newly occurring condition. The same argument applies to this condition as to the one preceding it, so an infinite regress necessarily follows.

If such a regress necessarily follows, so too does the perpetual succession of events. These cannot proceed from a beginningless, complete cause in which no event subsists, since that would require all its effects to coexist with it: every effect of a complete cause must coexist with that cause, and it cannot become the cause of something after not having been its cause without some causal factor arising from it. If successive events may subsist in it, then, on every supposition, events connected with the beginningless being must subsist in it. This argument is therefore invalid.

Moreover, their ancient philosophers say that the First moves the celestial spheres through a motion prompted by longing, just as a beloved moves the one who loves him. They did not state that the celestial spheres were brought into being by the First, or that they were effects of an efficient cause.

It must therefore be said that they necessarily exist in themselves, yet depend for their motion upon a mover distinct from them. Anyone who holds this position cannot say that the necessarily existent being