This version of the site is now archived. See the next version at v5.chriskrycho.com.

Classical Mechanics Doesn't Exclude Miracles

Against an argument which isn't even coherent, much less a defeater.

May 17, 2016Filed under theology#m. div.#philosophy#science#sebtsMarkdown source

The following was written in partial fulfillment of the requirements of Dr. Greg Welty's Philosophy: Science and Religion class at Southeastern Baptist Theological Seminary.


Does classic (Newtonian) physics constitute a defeater for belief in special divine action?

It is a common-place of some older philosophy of science and religion to suppose that the universe described by Newton’s laws of mechanics, Maxwell’s equations, and so on was a place of such regularity that there was no room for miracles. Because the laws posited deterministic systems in which the outcome of any given system could be known exactly, given the total set of antecedent conditions, some philosophers took the system to be indicating that determinism was a fact of the universe. Divine intervention would then be ruled out: God interacting with the universe would break Newton’s laws of mechanics and Maxwell’s laws of electromagnetism, and scientific laws more generally. Antithetical though this stance might seem to be to the Christian faith, a number of prominent philosophers and theologians, including such high-profile figures as Mackie and Bultmann, have affirmed this premise and integrated it into their theologizing. They were willing to affirm the “C phenomena”—God’s creating, conserving, and concurring work in the world—but not the “M phenomena” of miracles, God intervening directly in the world.

The first and most obvious problem with the idea that the scientific laws in question would be violated by a divine special intervention is that the laws themselves specify that they hold for closed systems. Newton’s laws of mechanics, for example, require conservation of mass and energy within a system—as long as, and only as long as, there is no external input into the system. If an external force does act on a system, then momentum (e.g.) is not conserved. Likewise, Maxwell’s formulations describe the behavior of electromagnetic fields in a closed system. God intervening, however, would by definition mean the system is not closed. It is not that God would be violating the laws. Rather, the laws describe a different situation from the one in which God acts specially.

Theologians such as Mackie and Bultmann who rejected miracles as “mythologizing” and out of bounds did not deny that God interacted with the world in any way, only that he did not interact specially with it. Unfortunately, the arguments they raise against God’s acting specially in the world argue against God’s acting in the world at all. Their argument runs something like this: if the state of the world is known at time T, and these laws hold, then the state of the world at time T* can be known as well. But if God specially intervenes, if he engages in a miracle, then this is no longer so. That would be violating the laws, and so he does not (perhaps cannot, if he wishes to uphold his world) perform miracles. However, precisely the same is true of those “C-phenomena.” If God had not created the world, obviously the world would not exist and nothing would occur. If he does not conserve the world so it continues to exist, then no matter what was known about the state of the world at time T, nothing whatsoever can be said of it (even that it still exists) at time T*. If he does not continue to concur with the function of the world he has designed, so that the laws he designed remain in force, then chaos follows. Whatever was so at T is in no way related to what happens at time T* if God is not upholding the causal powers of everything in the universe. Miracles, then, are not special in this way. Their specialness is in their distinction from the way God ordinarily conducts himself in the world.

It might here by objected that this leaves the theist with no way to distinguish between miraculous and ordinary events: both are simply the outcome of God’s will. This is patently false. On this objection, no one could ever identify any rare event, nor claim that something had happened which had never happened before. Nor could science develop; it is precisely identifying outlying phenomena and ways things differ from human expectations and current predictions about the world which drives scientific exploration. If indeed God conserves and concurs with the universe in a pattern he ordained, then the times when he acts unusually—out of step with the normal—will look quite different.

One further objection might be raised, about the inconsistency of God’s acting specially in the world at all. Why, the skeptic about miracles might ask, would God need to act in the world in these ways—should he not be able to set everything up ahead of time so that things fall out without his intervention. This has an apparent simplicity in its favor. It seems, though, that it assumes a particular view of the desires of God—for a basically mechanical system in which he will never need to intervene. If instead God desires to be known by some of the creatures in his world, it seems the opposite is true. Establishing an orderly world will not only make it habitable for those creatures, and will not only allow them to flourish and succeed therein; it will allow him to reveal himself to them by way of miracles. If the world were chaotic, no event would seem strange. If he never intervened, he would be difficult or impossible to know. Precisely because he creates an orderly world and both conserves it in being and concurs with the causal powers with which he initially endued it, the times when he does act distinctively are revelatory.

In light of all this, any discussion of God “breaking” or “violating” the laws of nature seems entirely wrong. The laws simply do not apply to those conditions. They describe what happens in the case when the world proceeds in the ordinary way, precisely because of God’s creating, conserving, and concurring with the world. But God is not constrained by them; the regularities exist because he desires them to! He is free to act in different ways when it suits his purpose.