A common objection to [Thomas Aquinas' first way](https://www3.nd.edu/~jspeaks/courses/mcgill/201/aquinas-cosmological-argument.html), the argument from motion (which means rather something like change), is that the second premise is flawed: 

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> It is certain, and evidence to our senses, that some things are in motion. Now whatever is in motion is put in motion by another, for nothing can be in motion except it is in potentiality to that towards which it is in motion; whereas a thing moves inasmuch as it is in act. If that by which it is moved be itself moved, then this also must needs to be moved by another, and that by another again. But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover, seeing that subsequent movers move only inasmuch as they are moved by the first mover: as the staff moves only because it is moved by the hand. Therefore it is necessary to arrive at a first mover, moved by no other; and this everyone understands to be God.”
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> ([*Summa Theologiae* - First Part: Question 2, article 3](http://dhspriory.org/thomas/summa/FP/FP002.html#FPQ2A3THEP1))
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The flaw in the premise comes supposedly from working with an outdated physics which does not incorporate Newton's Law of Inertia (= LI). In Newton's own words the LI is stated as:

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> Every body perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed thereon.
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> *Philosophiae Naturalis Principia Mathematica,* Law I.
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A lot of replies are possible to this objection. Probably the most fascinating (and to me the most convincing) would be, that one modern possible explanation for inertia relies on the quantum fluctuations of empty space. So this would be the “mover” in this case.

Anyway, if we ***reject*** the idea that spatial movement is ***not*** a kind of *change* or *movement* in the Thomistic-Aristotelian sense – which I think we definitely should –, we must find a “mover”, or, in my view, the premise is seriously put into question.

I'm not completely unsympathetic to the idea that a strong and clear-cut contradiction can put a straight-forward interpretation of an empirical finding (in this case: “There is no ‘mover’!”) into question. This is because any straight-forward or minimal interpretation of an empirical finding appeals to Occam's razor, which is itself just a principle of reason.

Still, I don't see such a contradiction in the LI or all three Newtonian axioms. Neither do I see it in the metaphysical theory that infinite change can be brought about by a *finite* *unchanging* “mover”, like the momentum which a body possesses.

The LI may not be strictly true or may be incomplete and Aquinas may then have become vindicated, but for me this would seem to be just a highly contingent outcome. So, how can we justify the suspicion that in the case of the LI we just haven't found the “mover” yet? And why should we reject the metaphysical theory that infinite change can be brought about by a *finite* *unchanging* “mover”?

PS: Yes, [this question](https://philosophy.stackexchange.com/questions/17923/why-must-objects-be-moved-by-other-objects-in-aquinas-first-way-argument-for-go) is similar on the surface. But there the premise was probed in a more abstract way. Here we put the focus on the most serious concrete counterexample.