Newton and the God of the gaps

I made a gaffe in a BioLogos comment the other day by inexplicably citing Kepler instead of Laplace as the person who showed that Isaac Newton’s famous argument for divine meddling with natural laws was unnecessary and wrong. But in sorting myself out I discovered to my surprise that the whole tale, the historic basis of criticism of the “God of the gaps”, is yet another example of science-religion mythology, like Galileo’s persecution by Christianity or Bishop Wilberforce’s apocryphal remarks to Huxley. Oddly enough, or maybe not, Googling the subject took me first to the BioLogos FAQ.

The classic tale, remember, is this. Newton formulates his laws of planetary motion, but finds they don’t completely account for the data, so he is forced into a supernaturalist fudge which assumes that God tinkers periodically to correct the maths. Newton also says that the current regular orbits couldn’t have arisen without God’s input. His contemporary Leibniz replies with the accusation that Newton’s idea implies a God too incompetent to get it right first time (isn’t that a totally familar argument from TEs in the evolution discussions?). As BioLogos‘s anonymous author puts it:

In both of these examples — one related to the ongoing motion of the planets and the other related to the origin of the motions — Newton is employing textbook God-of-the-gaps reasoning. Scientific theories are proposed to explain as much as possible, and then God is brought in to cover any remaining unexplained gaps in the explanation…

After a while, as we maybe have read, the mathematician Laplace sorted it all out. BioLogos again:

We now know that Newton was wrong on both counts. The gravitational perturbations that planets experience are so completely balanced that they average out to zero over time… And it was a straightforward application of Newton’s theory that revealed this. Newton simply had not done all the calculations to see if his intuition was right.

The only problem with this is that it’s untrue on nearly every count. To make reading easier, I’ll tell the story here, and put all the links to back it up together at the end.

First, Newton’s science was from the start intended to show how God works, not to explain nature apart from God:

When I wrote my treatise about our Systeme I had an eye upon such Principles as might work with considering men for the beliefe of a Deity and nothing can rejoyce me more then to find it usefull for that purpose.

Then he correctly judged that his theory could not solve the three-body problem (it’s not a simple application of it) and concluded (on the scientific grounds of existing perturbations from comets, etc) that the solar system might well be headed towards eventual instability, unless God were to perform its “reformation.”

Leibniz’s mockery, in contrast, stemmed entirely from his metaphysical presuppositions, not observational science:

Sir Isaac Newton and his followers have also a very odd opinion concerning the work of God. According to their doctrine, God Almighty wants to wind up his watch from time to time: otherwise it would cease to move. He had not, it seems, sufficient foresight to make it a perpetual motion.

Later, along comes Laplace, whose mathematical “proof” conveniently confirms his own metaphysics of material determinism, and puts the cap on the “God of the gaps” fallacy … or it would have done, had he not been in error:

It is an unfortunate quirk of history that a mathematician, Laplace, claimed (1787) to have proved that the solar system is stable thus claiming that Newton was wrong. However, it was rather the mathematical proof that was wrong. Although this mistake is widely recognised in the mathematical community, outside of the mathematical community the fallacy of the proof is less known, hampering thought development.

Essentially, Laplace and subsequent mathematicians used approximations that invalidate their results. Subsequent work has shown the solar system to be at least partly chaotic in nature, and still mathematically incalculable. Only computer simulations of the last few years have been able to show that most (though not all) projections suggest the present planets’ survival until the Sun’s death, though minor changes in initial parameters would lead to major disturbances of planets within their orbits, with who knows what unforeseen consequences. Maybe 1% of simulations show Mercury becoming unstable and potentially trashing the inner solar system.

Meanwhile Laplace’s nebular hypothesis, which supposedly plugged the other Newtonian “gap” of the system’s initial formation, has been shown to have holes of its own. Newton was right about both the potential instability, and the special conditions needed for the formation of our sytem. He never even said that God’s intervention was necessary to maintain planetary movements – just that those planetary movements might end in disaster unless God were to intervene to correct them. And that disaster, though found to be a smaller risk than he estimated, is still a possibility. As one writer puts it:

These recent advances are the beginning of a quest to tease out the critical properties of our solar system (and its subsystems) that give it the curious character of being only marginally chaotic or marginally stable on time spans comparable with its current age. It is but a part of the quest to understand what processes of formation (and perhaps initial conditions) led to this remarkable system in nature and how common such systems are in our galaxy and the universe.

I would add, too, that the stability we do see depends partly on relativity considerations completely unforeseeable in Newton’s day. Gregory Laughlin writes:

Simulations show that orbital chaos can lead to collisions between Earth and the inner planets. But Einstein’s tweaks to Newton’s theory of gravity render these ruinous outcomes unlikely in the next few billion years.

Apart from debunking the common myth, the most interesting aspect of this to me is the real shape of Newton’s thought. The conflict with Leibniz launched a correspondence with Newton’s follower Samuel Clarke, who seems to have conducted it more or less as Newton’s sock-puppet. Note that Leibniz, as I said, started this as a theological or metaphysical, rather than a scientific, argument.

Clarke complained that Leibniz’ concept of God as a “supra-mundane intelligence” who set up a “pre-established harmony” was only a step from atheism: “And as those men, who pretend that in an earthly government things may go on perfectly well without the king himself ordering or disposing of any thing, may reasonably be suspected that they would like very well to set the king aside: so, whosoever contends, that the beings of the world can go on without the continual direction of God…his doctrine does in effect tend to exclude God out of the world.”

Those words seem prophetic of the subsequent scientific project. Newton is sometimes described as a Deist, but this correpondence shows he is anything but that. His difference with Leibniz is that Newton sees God as involved both in lawmaking and law-enforcement, whereas Leibniz sees God as only lawmaker and sustainer (sound familiar?). Newton would be quite untroubled by any proof that the solar system was designed to be self-corrrecting, because he would simply transfer the phenomenon to the former category. But through theological principle, not through scientific inadequacy, he insists that the “natural universe” ought, as a matter of course, to include areas of God’s providential (ie non law-like) involvement. His belief of a God who was more than an irrelevant hypothesis demanded it, if not in planetary mechanics then elsewhere – perhaps in evolution, had he known of it.

This shows beyond any doubt that Newton would have consciously rejected the BioLogos FAQ’s critique of the God of the Gaps argument on theological grounds (as well as correcting them about his scientific reasoning) – and even more so since Leibniz’s own words against him are used by TEs to deny divine action in the evolutionary process. One wonders why TEs feel closer to the deistic Leibniz and the atheist Laplace than to Newton on this – it seems doubtful that his Arianism is to blame.

Here’s another quote from the father of modern science:

In the absence of any other proof, the thumb alone would convince me of God’s existence.

Where in today’s debates would that place him, do you suppose?

Refs:
http://en.wikipedia.org/wiki/Isaac_Newton%27s_religious_views
http://www.nature.com/nature/journal/v459/n7248/pdf/459781a.pdf
http://www.ias.edu/about/publications/ias-letter/articles/2011-summer/solar-system-tremaine
http://www.math.lsa.umich.edu/~fornaess/files/newtonenigmaoct04.ps
http://www.pnas.org/content/98/22/12342.full