Does naturalism, as a comprehensive worldview, stand up against scrutiny?
We each hold a worldview that is shaped by certain beliefs we choose to hold faithfully. We all perceive life through the lens of our personal worldview, which acts as a sort of window into reality. Without exception, every worldview has the potential to clarify, distort, or inhibit our ability to see objective truth. An effective worldview is one that provides an explanation of the facts that allows us to view and understand reality as it truly is.
One worldview, subscribed to by most atheists, is naturalism. Naturalism states that the universe consists entirely of natural forces and elements; all events can be explained via the laws of nature.
Ronald Nash, a professor at Syracuse University, suggests we think of the universe as a sealed box. Everything that happens inside the box occurs due to forces and elements that also exist within the box (the natural order). Nothing exists outside the box. Therefore, nothing outside the box (outside the natural order) has any causal effect within the box. To believe otherwise would be to embrace the super-natural.1
If there are any events, properties, or substances that naturalism cannot explain, then this worldview would be insufficient as an overall view of reality. Of course, it could still be useful in some capacities, but it would lack complete explanatory power in regard to our existence. Presently, there are two lines of evidence—one scientific and one philosophical—that call into question the adequacy of naturalism as a comprehensive worldview.
Big Bang Cosmology
Those who subscribe to the Big Bang theory believe in the birth of the universe; that is, all matter and energy had an ultimate beginning. The Big Bang theory is a product of Einstein’s theory of general relativity. It has subsequently received validation from observations that confirm various predictions of the model, including the expansion of the universe, the proportions of light elements present in the universe, and the existence of microwave background radiation left over from an explosive creation event.2
From 1966 to 1970, British astrophysicists Stephen Hawking, George Ellis, and Roger Penrose extended the equations of general relativity to include space and time. Their papers showed that space and time must also have an origin—an origin coincident with that of matter and energy.3 In other words, if general relativity accurately describes the physics of the universe, then all matter, energy, space, and even time itself share a singular origin at some finite point in the past.4
It stands to reason that, if Big Bang cosmology is true, then the most credible and defensible explanation would require a cause external to the universe itself. Let me explain a bit. The law of causality demands that effects emanate from causes. The Big Bang had the effect of creating all matter, energy, space, and time in this universe (all of nature, in other words). However, the Big Bang itself also required a cause. Since the cause must exist outside the effect (the universe itself, in this case), whether mechanistic or personal, this cause would be supernatural.
Big Bang cosmology presents considerable difficulty for the worldview of naturalism. Author Jim Holt elaborates, “The problem with the science option would seem to be this. The universe comprises everything that physically exists. A scientific explanation must involve some sort of physical cause. But any physical cause is by definition part of the universe to be explained. Thus any purely scientific explanation of the existence of the universe is doomed to be circular.”5
Holt’s point is that it would seem illogical to appeal to the universe as the cause of its own existence. Once we are forced to consider a cause existing outside of the universe itself (meaning any cause, whether it be mechanistic or personal), then we are compelled toward an explanation outside of the worldview of naturalism.
Libertarian Freedom (Free Will)
Those who subscribe to naturalism also tend to embrace materialism. These views often go hand-in-hand. In philosophy, materialism is a view of the world that states that everything that exists in the universe is strictly material or physical. There are no spiritual or nonphysical forces or elements.
The doctrine of determinism flows logically and rationally from materialistic naturalism. Determinism is the view that every event that happens, including human choices, is caused to happen. Additionally, it means that what happens in the future could not have been different, given what has happened in the past.6
So if naturalism is true (meaning everything is explainable via the laws of nature) and materialism is true (meaning everything that exists is strictly physical), then whatever happens in the universe is determined to happen by the laws of nature acting upon its matter.
Consider the analogy of pool balls on a pool table. Once the cue ball is struck, this will determine all of the events that will occur on the table. Each ball’s final resting place is determined by the laws of physics acting upon the particles of matter. Philosopher John Seale notes that in the same way “once the existence and trajectories of all the microparticles in the universe are set, then the entire physical history of the universe is determined by the behavior of the microparticles.”7
What this must mean, from a naturalistic perspective, is that we could not have free will. We do not have the ability to think, act, and reason freely. As The Center for Naturalism states, if naturalism is true, then “We are not ‘causally privileged’ over the rest of nature, that is, we don’t get to cause without being fully caused ourselves. To think that would be to hold a supernatural view of ourselves, the opposite of naturalism.”8
Philosopher J. P. Moreland further elaborates, “It should be obvious why free will is a feature of the world that a naturalist must deny. There is not nor will there ever be a plausible explanation as to how one can start with dead, brute, non-teleological [non-purposeful], law-governed matter . . . and generate the sort of . . . agent required for libertarian freedom by simply rearranging parts into new . . . relations.”9
As noted earlier, Big Bang cosmology flows naturally from Einstein’s theory of general relativity, which is one of the most widely tested and confirmed theories in science. The experience of our own freedom—our own free will—is one of the most self-evidential facts we can observe. The concepts of rationality, responsibility, knowledge, and expertise would have no foundational merit if we were unable to think, act, and reason freely.
If naturalism is incapable of accounting for 1) the creation of the universe and 2) our existence as free agents, then it is insufficient as a comprehensive worldview to explain the whole of reality.
As internationally respected philosopher and atheist Thomas Nagel surmises:
For a long time I have found the materialistic account of how we and our fellow organisms came to exist hard to believe, including the standard version of how the evolutionary process works. The more details we learn . . . the more unbelievable the standard historical account becomes. . . . it seems to me that, as it is usually presented, the current orthodoxy about the cosmic order is the product of governing assumptions that are unsupported, and that flies in the face of common sense.10