Kirsten Walsh writes…
In my last few posts, I’ve discussed some of the lesser-known aspects of Newton’s work. In my first post on this topic, I talked generally about how we might consider Newton’s chymistry, theology and Church history to be methodologically continuous with the experimental philosophy of the Principia and the Opticks. And in my second post I considered Newton’s alchemical tract, now referred to as ‘Of Natures obvious laws and processes in vegetation’, and identified several features that seem to highlight Newton’s early (albeit tacit) commitment to experimental philosophy.
In today’s post, I’ll begin to discuss an important but relatively understudied aspect of Newton’s work: his theological methodology. Since this blog is primarily concerned with early modern experimental philosophy, I’m going to start with the famous passage from the General Scholium to the Principia: “to treat of God from phenomena is certainly a part of natural philosophy”. The meaning of the first part of the statement is clear: we have epistemic access to God via our observations of the world. And so, from the phenomena, we can learn about God’s nature and divine will—in the same way that we can learn about, say, gravity. But in what sense is this ‘a part of natural philosophy’? That is, how does this statement fit with Newton’s stated views regarding that topic?
In the General Scholium, Newton explains that, while the laws of motion explain why celestial bodies move in Keplerian orbits, they cannot explain how celestial bodies come to be in their present orbits. And so, he writes, “This most elegant system of the sun, planets, and comets could not have arisen without the design and dominion of an intelligent and powerful being”. Prima facie, examples such as this don’t fit with Newton’s natural philosophical method. He seems to employ non-empirical background assumptions about the nature of God’s intervention to plug gaps in his theory. This looks dangerously close to feigning hypotheses. Moreover, from these assumptions, he seems to leap right to the first cause, blocking further scientific inquiry, and contradicting the ‘satis est’ attitude he adopts in his natural philosophy.
I think, however, that Newton’s treatment of God from phenomena is more consistent with his method of natural philosophy than it first appears. But to recognise this, we need to look more closely at how Newton approaches God from the phenomena. In fact, Newton treats of God from phenomena in several different ways. One approach is to move directly from the phenomena to the nature of God’s interactions with the world. For example, in the General Scholium, Newton notes that all celestial bodies move in regular orbits, which tells us that neither planets nor comets encounter any kind of resistance in their orbits. Newton uses the lack of resistance to argue that celestial bodies do not move through vortices but through empty space. However, this phenomenon also reveals that, while God is omnipresent and substantial, he is not material:
God is one and the same God always and everywhere. He is omnipresent not only virtually but also substantially; for action requires substance. In him all things are contained and move, but he does not act on them nor they on him. God experiences nothing from the motions of bodies; the bodies feel no resistance from God’s omnipresence (Principia, Cohen & Whitman translation, pp. 941-942).
Another way Newton approaches God is to ask after the nature of his interventions. Here, Newton identifies explanatory gaps between phenomena and theory, and asks whether God could be acting, and if so, what is the nature of that action? For example, in a letter to Bentley Newton notes that that his theory of universal gravitation can explain the motions of the planets, but not their original sizes or positions in the solar system. The latter, he concludes, can only be explained by divine intervention. That God works to achieve such perfect balance in the system of the world tells us that he is “not blind and fortuitous, but very well skilled in mechanics and geometry”. Here, the insight is that gravity can destabilise the system of the world—and so the physical world constantly tends towards decay. Thus, God is required to use his skills of design and maintenance to prevent this from happening.
Neither approach looks like ‘feigning hypotheses’. For one thing, Newton doesn’t allow his thinking about God to justify or constrain his theorising. Rather, God is introduced after the physical theory has been established to see what it can teach us about the nature of his intervention. And for another thing, Newton’s ideas about God don’t result from speculation, but from rigorous study of both scripture and the natural world, and the careful application of reason. It is from our post-Enlightenment perspective that rigorous study of scripture seems to fall outside of natural philosophy.
Moreover, Newton’s introduction of God doesn’t stop inquiry. Rather, it raises further questions about how and why God intervenes on the system of the world. And these, in turn, lead back to physical inquiry. For example, Newton’s discussions about God’s role in the sizing and positioning of the planets leads to a fruitful inquiry about the specific compositions of the planets and why the biggest planets are furthest from the Sun. That the inquiry continues highlights the fact that Newton doesn’t view the cause of a given phenomenon as either natural or supernatural: every phenomenon is generated by both natural and supernatural causes. That is, physical objects act on one another as natural causes, subject to physical and mathematical laws, but God is the first-cause, and hence, behind all actions. And so, when Newton treats of God from phenomena, the inquiry doesn’t end there.
Finally, as a good experimental philosopher, Newton knows that we only have direct epistemic access to the evidence of our senses, so our knowledge of God is necessarily limited. However, as he makes clear in query 28 of the Opticks, we mustn’t be put off by our inability to discover the first cause directly. Instead, we must work to uncover intermediate causes—proximate causes—and work slowly to uncover deeper and deeper levels of causes until we come to the first cause. And, importantly, these intermediate causes can also reveal the nature of God:
And these things being rightly dispatch’d, does it not appear from Phænomena that there is a Being incorporeal, living, intelligent, omnipresent, who in infinite Space, as it were in his Sensory, sees the things themselves intimately, and thoroughly perceives them, and comprehends them wholly by their immediate presence to himself… And though every true Step made in this Philosophy brings us not immediately to the Knowledge of the first Cause, yet it brings us nearer to it, and on that account is to be highly valued (Optics, Dover edition, p. 370).