It’s often said that the only thing atheists have in common is what they disbelieve. It’s also often said that disbelieving in God is just as much a religious belief as is believing in God, or more exactly, that both belief and disbelief rely on faith. All of these assertions are incorrect.
Atheists don’t have a religion — but they do have something in common beyond what they disbelieve. What atheists share is a natural worldview.
Sometimes that worldview is a bit confused, incorporating too much from the still dominant supernatural worldview. But understood clearly, the natural worldview is simply the belief that body precedes mind. The supernatural worldview, of course, takes the opposite tact: that mind precedes body. We see right off from this that naturalism is not merely a refusal to believe in supernaturalism. It’s based on its own specific hypothesis about the nature of the world.
Logically speaking there are 3 possibilities concerning existence: physical before mental, mental before physical, and mental/physical concurrent. The first is naturalism, the second supernaturalism, and the third a hybrid which deserves a name of its own. We might call it “non-physical naturalism” or “hybrid supernaturalism” or, perhaps, pantheism.
A good many people today embrace this 3rd possibility, but whatever it is, it is not naturalism. An essential tenet of naturalism is physicalism, and physicalism locates naturalism firmly in the camp of “physical before mental.”
But isn’t it impossible to know which worldview is correct? Aren’t we forced to simply take our preferred choice on faith?
As a matter of fact, we are not. This may seem surprising, but it shouldn’t be. Whether mind or matter is primary is an empirical question, for the answer makes a difference to how we must acquire knowledge of the world. By studying how human knowledge actually works, scientists can reliably infer which worldview best fits our universe.
Now, it might be objected that no inference to the best explanation can be definitive. That’s true, of course. The scientific method is always a matter of inferring the best explanation for the evidence at hand, and as such it is always falsifiable (which simply means that new evidence may come to light and/or a better explanation be devised).
But this aspect of the scientific method is itself one of the key clues we have about which of these worldviews is correct. It’s long been recognized that the human mind employs two types of knowing. Following Kant, these are referred to as analytic and synthetic. All our knowledge about the world itself is of the synthetic sort, and we have found that we most reliably obtain synthetic knowledge when we employ the scientific method of inferring which abstract model best fits our evidence.
But our abstract models themselves consist of logical and mathematical relationships which we apprehend not synthetically but directly and analytically. Why would such a dual knowledge-system have evolved in humans? Well, it’s easy to comprehend its necessity in the context of naturalism. If existence has no underlying mental blueprint, then the world can’t be known directly. The only practical way to “know” such a physical world would be by the two-step process of devising analytic models and utilizing something like the scientific method to pick the most useful model based on its predictive value. Knowledge of the world therefore consists of “virtual” models (consequently “synthetic”) which are inherently falsifiable because none could ever be a match with any underlying mental reality (since under the model of naturalism no such mental substrate exists).
Since this seems to be a good description of how humans (especially those most successful knowers who are called scientists) actually come to know the world, the natural hypothesis fits well.
On the other hand, interestingly, there would be no need for such a synthetic process of knowing to evolve in humans if naturalism were false, since in that case the world would have an underlying mental substrate that could be known directly and analytically. The alternative worldviews do not fit well, since they cannot account for the necessity of knowing the world synthetically.
Put simply, we are forced to rely on synthetic knowledge of the world because we cannot in fact apprehend the world directly. The strong implication of this is that the physical world contains nothing capable of being apprehended directly: it contains no mental substrate. If so, naturalism is true and the other two worldview options are false.
My intent here is not to make a full-fledged argument for naturalism, but rather to buttress my point at the beginning: determining the correct worldview is something that can be done by investigating the nature of the world and of ourselves as knowers. Consequently, which worldview is correct is not a matter of faith but of scientific inference.
Summary: (1) We don’t have to rely on faith to know whether there is an intelligence behind the universe. (2) Atheists agree on a positive worldview: physical naturalism.