It can be very helpful to draw a distinction between science and scientism. Science is a method, while scientism is a philosophy. Science gives us a practical means by which to investigate the physical, material domain, whereas scientism gives us a worldview in which only that special domain counts as truly real.

My students frequently speak of Science (always intoned with a capital S) as a body of deliverances, a set of propositions that are unquestionably true. I hear them begin arguments with such phrases as “According to Science…” followed by a claim, which they mean to be an unshakable premise. This way of talking about capital-S Science, however, is unhelpful for a couple reasons.

In the first place, it is unclear which propositions count as indubitably “proven” by Science. Where does one go to find the list of special propositions? Is there some central body responsible for maintaining a catelogue? Some scientific claims are almost universally accepted among scientists, while others are highly controversial. In between, however, we have a whole spectrum of acceptance, and it would be quite arbitrary to pick some point along this spectrum beyond which a proposition gains the special “According to Science…” stamp of approval.

In the second place, even the set of claims with near-universal acceptance in the scientific community changes remarkably over time. Without a solid knowledge of history, we can easily lose sight of just how little time has past since such crucial developments as quantum mechanics or general relativity. Before these developments, one set of propositions looked rather unshakable, but afterwards, the total picture of what is scientifically “certain” looks rather different.

In reality, it is better to think of science as a certain methodology or practice whereby hypotheses are tested against the empirical data from carefully designed experiments. Importantly, when we say that the data must be empirical we are placing an in-principle restriction on the kinds of data that can be gathered—before we even conduct the experiment. At the beginning of the scientific revolution, the study of nature formed only one part of philosophy, and it was not entirely clear where to draw the line between theology and the study of light, between Aristotelian metaphysics and the study of frogs, or between Arabic astrology and the study of metals. By bracketing off all appeal to non-empirical data, the experimenter can focus on a particular domain—that of sensible nature—and ignore questions about all other domains. This bracketing is practically useful in advancing our knowledge of this one domain, and historically led to incredible advances in our knowledge of the sensible world and the technologies that spring from this knowledge.

We must realize, however, that bracketing off questions about astrology or metaphysics hardly settles them.

To illustrate, imagine a couple trying to figure out what to do on vacation. The conversation keeps getting side-tracked by a preexisting conflict between the husband and his mother-in-law—who will not be on the trip. Both husband and wife are emotional about this conflict, so as soon as the topic comes back around to the mother-in-law, things spiral out of hand and they don’t make much progress on their planning. At one point, the wife makes a very sensible suggestion: “Since we need to figure out our vacation plan in the next few days and since the conflict with my mother does not directly affect what we are going to do, let’s just set that topic aside—it’s banned from the present conversation—so that we can focus on getting this planning done.” The husband agrees, and over the next few hours, they make near miraculous progress. When the evening rolls around, however, the wife remarks, “See! You never really had a conflict with my mother. We’ve been talking for four hours without you mentioning her, so therefore, having that conversation must not have been necessary in the first place.”

The first (quite helpful) suggestion of the wife mirrors that of the scientific method, while her latter (not so helpful) conclusion mirrors that of scientism. My impression is that people commonly arrive at this latter worldview through one of two routes which we might call “articulate” and “inarticulate” scientism. The articulate adherent of scientism looks at the enormous success of the scientific method and what he sees as the comparative failure of previous methods and he forms a more or less explicit argument:

1. Including angels and demons, fairies and ghosts, the soul and especially God in our explanations of the world led to very few if any results.
2. By contrast, excluding all such entities systematically led to enormous benefits both in terms of material goods and in terms of our knowledge of the universe.
3. One ought to stop believing in things that, when included in the discourse, hold us back. Or said another way, (1) and (2) add up to positive evidence that there are no angels or demons, fairies or ghosts, the soul or especially God.
4. Therefore, one should only believe in those entities or kinds of entities that are included in our latest science.

We should be able to see by now, that (2) is rather obviously true, at least if we only look at progress in the technological domain, while (1) and (3) are the critical sticking points. Frequently, people like me tend to challenge (1) by pointing out various enormous discoveries or profound truths to be found in pre-scientific philosophy. Right now, however, we are focused on (3). Is it really credible that bracketing a certain domain of reality for the sake of practical progress gives us any evidence for the non-existence of that domain?

In his little masterpiece, Mind and Cosmos, Thomas Nagel reviews the “increasingly sophistocated” attempts to reduce consciousness to physical states such as causal behaviorism, identity theory, or functionalism:

But all such strategies are unsatisfactory for the same old reason: even with the brain added to the picture, they clearly leave out something essential, without which there would be no mind. And what they leave out is just what was deliberately left out of the physical world by Descartes and Galileo in order to form the modern concept of the physical, namely, subjective appearances.¹

It’s the same pattern that we observed above: intentionally leaving out certain domains or topics for the sake of making progress in a single restricted domain, but then turning around and somehow taking this bracketing as evidence that everything outside the privileged domain must be either reduced to it or treated as unreal.

The silliness of this principle becomes even more apparent when we notice the question-begging nature of the kind of “progress” we are talking about. The advocate of this way of thinking will want to talk about steam engines, penicillin, the light bulb, and the internet, but will also want to bracket off any discussion of progress in law, spirituality, moral responsibility, or religion. But why should these domains be excluded from what counts as “real” progress, unless we have already concluded that those domains are unreal nonsense?

The inarticulate adherent of scientism is, in some ways, harder to deal with because he does not arrive at his scientism through a process of explicit reasoning. Instead, his picture of the world develops subtly through habits of thought and practice. He sits in one science class after another without ever hearing of angels or the soul, he forgets to even think of such things as potentially real beings (if he ever thought of them in the first place). Much of this exclusion is accomplished through tone rather than demonstration. In his science textbooks, he reads confident declarations about the way the world is, whereas what spiritual claims he does encounter in humanities classes or the History Channel are framed as fanciful and hypothetical “what ifs.” When asked, such a person may even say that he does believe in angels or the soul or that he is open to the idea. In his lived worldview, however, the kinds of things discussed by science are firmly held to be real in a way that everything else is not. It is hard to say what will ever shift such a disposition once it has become settled—except perhaps direct, first-hand experience of the supernatural, although this too may not be good enough.

In reality, most people of the scientistic stamp are a mixture of the articulate and inarticulate versions. They have within their mind some form of argument at greater or lesser degrees of careful reflection. But they also have within them, habits of thought more or less ingrained by a culture of secular materialism. My hope is that by simply pointing out the distinction between science and scientism, such people can gain a little more reflective distance from their own convictions and we can thereby work toward a more fruitful discussion.