When most people think of Albert Einstein’s contribution to physics, the theory of relativity is what comes to mind, and rightly so. What most don’t realize is that his Nobel Prize was actually awarded for explaining the photoelectric effect, a result which contradicted the classical understanding of light and helped lead to the development of Quantum Mechanics. Despite his major contributions to its development, Einstein was famously uncomfortable with the way randomness and uncertainty became so integral to the understanding of that new theory, often summed up in his quote, “God does not throw dice.”
This objection, however offhand it may seem, resonated with many physicists of the time. The glory of classical physics was how neat and tidy everything was. It offered the promise of determinism: if we could know perfectly the state of the universe at one moment and the laws that govern it, we could extrapolate forwards and backwards perfectly as far as we like. Despite the recognition that this ideal was well nigh impossible, there was comfort in the promise, and each step we took at least brought us closer to that perfection. The claim was that perfect knowledge of the natural world, the sort that is attributed to God, would ultimately be expressed in a deterministic mathematical formula.
The difficulty that Quantum Mechanics presented for Einstein and many others, physicists and non-physicists alike, is that the best picture of the physical world that it allows seems partial and incomplete. It implied that it is not just practically difficult but theoretically impossible to completely describe the current state of the world, let alone extrapolate forwards or backwards as we please. As bad as the loss of “perfect” knowledge of the world was for physicists, it further called into question the nature of God’s knowledge of the world. If some aspect of the natural order was inherently uncertain and unknowable what does this imply for God? Is God’s knowledge subject to this randomness, is he simply reacting to the whims of nature?
The image of God awaiting the results of a chance outcome is rightly viewed as absurd, but the solution was not a recovery of classical determinism. Even independent of the results of Quantum Mechanics, that view was philosophically flawed, and the attempt to understand God’s knowledge using it was even more so.
If physics could actually give us a complete description of the now and from that extrapolate forwards and backwards, then the past, present and future are logically the same and all equally “present.” In a sense, nothing “new” ever happens because everything is subject to absolute necessity. Every effect is completely defined by its cause, a picture of the world that is arguably static rather than dynamic, detracting from the very notion of time. There are a host of subtle problems this raises about necessity and contingency and what it even means to be a cause, but the most obvious difficulty with this view is that it leaves no room at all for free human activity.
Additionally, thinking of God’s knowledge in this way cripples the idea of His providence. If everything in nature simply happened necessarily based on what came before, it would seem reasonable to say that God’s knowledge is just the perfect working out of the complicated physics problem of the universe. As creator He knows how all things will work together and His providence simply becomes this human kind of foresight and His governance simply becomes setting things up to run perfectly. The danger inherent in this is to see God as the external Architect who only works on and understands the world on a natural level, more powerfully and perfectly than we ever could perhaps, but still on a natural level.
It took many years and much experimentation and calculation before the reality of the quantum world sunk in. Physicists eventually became comfortable with the success of Quantum Mechanics and settled into a new status quo that accepted a randomness and indeterminism underlying physics. Even those who sought alternative interpretations of Quantum Mechanics that might save determinism recognized that they had to bring in other phenomena that destroyed the crisp, clean classical worldview. Unfortunately, the damage done to the understanding of causality and of God’s providence by classical determinism remains.
Even if the natural world “throws dice” in its most fundamental interaction, this may simply be a physical manifestation of the inherent contingency of all material things. This idea would not have been so foreign to Aristotle and St. Thomas, who saw both necessary and contingent causes in the world around them. More importantly, this loss of absolute necessity does not threaten God’s absolute knowledge of the created order, for his knowledge is not limited to the particular mathematical and formal descriptions that we are able to develop in the sciences. God’s providence, His wise ordering of everything to its proper end, is above every natural cause. The certainty of God’s knowledge does not limit his power to create natural objects that can act in a truly contingent way. Einstein was right that “God does not throw dice,” but He knows perfectly the natural order that He created to do just that.