[Serious] Criticism of Aquinas' First Way or of the Proof of God from Motion.

[Neo-Scholastic]

On first blush, this seems to be the critical paragraph from the post in the other forum:

To sum up: Lamont, following Peter Geach, tries to show that Aquinas's proofs for the existence of God can be construed as a valid composition argument. I have argued that insofar as we can reduce the Five Ways to a composition argument, such an argument in no way yields the desired conclusion. The failure of Lamont's attempt is explained by the fact that he makes the proof of God's existence into a deductively valid composition argument only by begging the question with respect to the fundamental issue, namely, that the sum of all effects is really a group in need of a singular cause different from the causes of any of the effects of which it is the aggregate.

Personally, seems more like an analogy failure than a logical one. I would take the approach that since the God the Philosophers is both imminent and transcendent, the movement from potency to actuality happens simultaneously for all instantiations at every scale, not simply the most fundamental.