Can the universe account for its own existence? Can we find, within physics and cosmology, the reason for why physical reality exists at all? Cosmologists and physicists are hopeful that finding an answer to these questions is at least possible and maybe even plausible. For the cosmologist’s job is to search out the origin of the universe—or find out if it had an origin at all—to find out why it exists in the first place, and why and how it came to exist in its current state. Now cosmology has come a long way in the last century and it continues to advance in leaps and bounds. But despite the advancements of physics, I maintain that physicists will never in principle be able to explain the existence of physical reality.
I realize that in promulgation of this statement I am shouldering a great burden of proof, and that such a statement can even come across as arrogant. However, please note that it is borne out of careful logical study of the philosophy of science, and not from a petulant view of science or scientists. In fact, I have found that it is “skeptics” who arrogantly fail to recognize the explanatory limits of science, and by doing so would only take my aforementioned statement as arrogant because their vision is dogmatically colored by the lens of positivism. However, since this is not the time to get into the hypocritical creeds of the freethought community, let us return to the thesis at hand: science cannot explain why the universe exists. (Note that by “universe” I include any possible meta-universe or multiverse.)
Now, what gives me the right to assert such a blanket statement like this? Well, the nature of scientific inquiry itself does. You see, as I’ve pointed out before, science operates on inductive conditional statements like “if p, then q”. This is why scientists can run an experiment a finite amount of times and then generalize a conditional statement as a law. (Note again that such an exercise would be moot unless we took things to have shared essences.) And this takes us to the nature of scientific laws themselves. Scientific laws are mere descriptions of the way things tend to behave given certain ideal conditions. These laws are not prescriptive, in that they don’t inform substances on how to behave. Rather, substances behave the way they do and our formulated laws are informed by such behavior.
The pivotal point here is that scientific laws are ontologically dependent on existence, not the other way around. That is to say, scientific laws don’t obtain unless you first have something which actually exists and behaves in some way. That’s why the conditional statements of scientific law start with “if p,” meaning “if some state of actual affairs obtains in reality”. Now, what exactly does this have to do with science explaining the existence of the universe? Well, if existence logically precedes scientific law, then the latter cannot itself ever explain the former. That is to say, scientific law first needs something already in existence to describe the behavior of—it doesn’t describe non-existence—therefore science is reliant upon existence, and thus existence will always be a higher member in an explanatory chain. But in order for science to explain the universe it would itself need to be the higher member in an explanatory chain, and since this is logically impossible then it follows necessarily that science cannot in principle explain the existence of the universe.
There’s another point to be made here, however. It should also be noted that science cannot even account for its own laws. That is, science itself cannot determine why the laws are the way they are as opposed to being another way. Here’s why. Either (i) the reason scientific laws are the way they are is to be illumined by another scientific law, or (ii) the reason scientific laws are the way they are is to be illumined by an explanation not susceptible to scientific description. (i) is not a viable option because explaining scientific law by another scientific law just pushes the question back a step and doesn’t answer anything. Moreover, the question was to explain the set of scientific laws, and this cannot be done by another scientific law not in the set since the set already contains all scientific laws. Thus, option (i) isn’t even possible. (This is why arriving at a scientific Theory of Everything is not possible as well.) If one chooses (ii) then we arrive at an explanation not susceptible to science, which only proves my point, namely, that scientific law cannot explain itself.
Implications for naturalism
Now all these points actually have important implications for naturalism as well. For most ontological naturalists naturalism seems to imply physicalism—note that I’m not claiming that naturalism necessarily entails physicalism, only that most naturalists are physicalists. The reason for this is that if all that exists is the natural world and the natural world contains all matter, energy, space and time, then all that exists in the natural world is physical—or it at least supervenes on the physical—and therefore all that exists is physical.
But this means that physics itself should be able, in principle, to arrive at a theory of everything and thereby explain the existence of the physical world. But we’ve just seen above that this is what physics and science cannot, in principle, do. And thus physicalism and naturalism are false—again, based on those who would derive physicalism from naturalism. David Bentley Hart articulates the point numerous times in The Experience of God:
Physical reality cannot account for its own existence for the simple reason that nature—the physical—is that which by definition already exists; existence, even taken as a simple brute fact to which no metaphysical theory is attached, lies logically beyond the system of causes that nature comprises; it is, quite literally, “hyperphysical,” or, shifting into Latin, super naturam. This means not only that at some point nature requires or admits of a supernatural explanation (which it does), but also that at no point is anything purely, self-sufficiently natural in the first place. (p. 96)
To drive the point home one last time, physics and science are at a loss to explain exactly why the physical world is the way it is, and why it exists in the first place. Science is explanatorily inert here. And this should not be the case if physicalism were true. Thus, because of the nature of the universe and the explanatory limits of physics, physicalism is false. What implications should this entail for naturalism? I’ll let the reader decide for themselves.