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What Is Science?

Jason Rosenhouse

May 18, 2006

Proponents of intelligent design (ID) offer a wide array of arguments in defense of their views. These arguments are, without exception, incorrect. In a better world, everyone would understand that and the issue would go away.

In this world, however, things are not so easily resolved. Much of ID’s support among the general public comes from people entirely ignorant of the basic facts and methods of science. For them, science refers not to a particular method of investigation, but rather to the totality of true statements that can be made about the world. And since they view it as self-evident that God exists, they believe that a science that makes no reference to God must be incomplete.

ID proponents find it rhetorically useful to play up this angle. They routinely tell their audiences that scientists dismiss ID not because of its lack of scientific merit, but because of arbitrary definitional conventions about what constitutes science. Sadly, they are sometimes abetted in this by naïve scientists who make, “It’s not science!” their main argument when publicly confronting ID.

Some ID supporters, however, are so enamored of their theory that they try to have it introduced into high school science curricula. When this happens it falls to the courts to decide whether such curricular changes are consistent with the constitutional prohibitions against mixing church with state. Schools, you see, are not allowed to promote sectarian religious beliefs. And one part of showing that ID is such a belief is showing that ID is definitely not science.

So the question of whether ID can reasonably be considered part of science is important over and above any consideration of the merits of its arguments. Furthermore, defeating ID requires educating the public not just in the basic findings of science, but also in its goals and methods. For these reasons it is useful to think about what science actually is.

Science is best viewed as an activity undertaken with a specific goal in mind. That goal is to understand the workings of nature. We measure our level of understanding by the extent to which we can make nature’s phenomena predictable and controllable. Any investigative technique that brings us closer to this goal can reasonably be considered part of science.

All of the standard pieces of the scientific method we learned about in high school - experimentation, hypothesis testing, inductive reasoning and so forth - have their role to play in bringing us closer to our goal of predictability and control. By contrast, hypothesizing the actions of ill-defined supernatural entities such as ghosts or poltergeists does not help us move closer to our goal. Consequently, the actions of supernatural entities play no role in modern scientific discourse. It is pragmatism, not bias, that leads scientists to abjure the supernatural in their professional work.

This pragmatic rejection of supernatural hypotheses is sometimes described by saying that scientists adhere to methodological naturalism (MN); naturalism because it rejects the idea of causality coming from outside nature, methodological because it is a convention for doing science, as opposed to an assumption about how the world actually is. ID proponents seize on this, arguing that MN is nothing but an arbitrary rule used to exclude ID from its place at the table. This claim is a bit rich, since in other contexts ID folks are keen to persuade people that their view implies nothing one way or the other about the reality of the supernatural.

More to the point, however, is that many of the terms that get thrown around in this discussion - such as testability, falsifiability, or MN- are really just ways of saying that scientists care about predictability and control. Saying that scientists adhere to MN in their work is really just shorthand for the fact that science is a very pragmatic enterprise, and that the naturalistic hypotheses are the ones that have historically proven useful. It is a phrase that accurately describes the way scientists approach their work, and it survives because the only alternative - methodological supernaturalism - has proven itself time and again to be utterly ineffective in bringing scientists closer to their goal.

I suspect my description of things will seem obvious to any professional scientist. Confronted with real data from an actual experiment, it is hard to see how invoking supernatural entities constitutes any advance over total ignorance.

But if defining science is as simple as I have suggested, then why do so many philosophers of science say that the demarcation problem, by which they mean the problem of finding a clear dividing line between science and non-science, is insoluble?

They say this because there is a difference between science in practice and science in theory. In practice it is usually fairly simple to distinguish science from non-science. Scientists have their goals and their standard methods for achieving those goals, and they seem to have little difficulty distinguishing topics that are worth their time from topics that are not. Philosophers, however, have different concerns. They are looking for checklists of abstract criteria that you could apply infallibly to any given human endeavor, and thereby come to a definite conclusion about whether or not the endeavor is science. And this turns out to be difficult indeed. The details can be found in any textbook on the philosophy of science.

The more florid pronouncements of certain philosophers notwithstanding, the insolubility of the demarcation problem does not imply that “science” and “non-science” are simply arbitrary labels that reflect cultural biases. A better way to view the situation is that science and non-science are opposite ends of a continuum, as opposed to rigidly defined categories. That there is a large gray area in the middle of the continuum does not change the fact that items at the extremes are easily identified as either science or non-science.

Perhaps my emphasis on predictability and control strikes you as misplaced. After all, is not science meant to be an objective search for the truth? The noted philosopher of religion Alvin Plantinga believes so. In his essay “Methodological Naturalism?” he responded as follows to the point about the pragmatism of scientific practice:

The claim that God has directly created life, for example, may be a science stopper; it does not follow that God did not directly create life. Obviously we have no guarantee that God has done everything by way of employing secondary causes, or in such a way as to encourage further scientific inquiry, or for our convenience as scientists, or for the benefit of the National Science Foundation. Clearly we cannot sensibly insist in advance that whatever we are confronted with is to be explained in terms of something else God did; he must have done some things directly; to know this would be an important part of a serious and profound knowledge of the universe. The fact that such claims are science stoppers means that as a general rule they will not be helpful; it does not mean that they are never true, and it does not mean that they can never be part of a proper scientific theory. (Italics in original, boldface added).

Plantinga, I’m afraid, gave away the store with that boldface remark. The fact that claims of direct supernatural action are not helpful is equivalent to saying that they cannot be part of a proper scientific theory.

Plantinga is defending a syllogism that many non-scientists would agree with. Roughly, he is arguing that: (1) Science encompasses all that is true. (2) God is true. Therefore, (3) God is part of science. Alas, there is a serious problem in viewing science this way. Truth, in the ultimate, metaphysical, capital-T sense, is a slippery beast. In defending some assertion about the natural world, what more can we say than, “It agrees with the data we have?” Even the most well tested scientific theory must face up to the possibility that it is effective only because it amuses some race of super beings to make it so. Indeed, knowing about such super beings would be an important part of any comprehensive understanding of nature. But since there is no practical difference between, “This theory is effective in predicting the outcomes of experiments,” on the one hand and “This theory is effective because super beings wish it to be so,” on the other, scientists are not being dogmatic in ignoring the possible reality of super beings.

Of course, it is possible to get carried away with this. Emphasizing pragmatism over truth does not mean that we must wallow in a relativistic morass in discussing the workings of nature. Scientists routinely describe their better-established theories as true, and I believe they are correct to do so. As long as it is understood that “true” in this context means “consistently effective at explaining and predicting empirical data,” no confusion should result. As a practical matter it seems reasonable to assume that the impressive fit between theory and data reflects something genuine about how the world actually is, but a person absolutely determined to reject this assumption is welcome to do so.

So why are people like Plantinga so eager to have their religious beliefs brought under the umbrella of science? Why is it not obvious to him that it is usefulness, and not ultimate truth, that is of importance to scientists? The reason, I suspect, is that Plantinga is only tangentially interested in proper scientific practice. His real interest is in winning for his religious beliefs the same respect accorded to the pronouncements of professional scientists. The enormous success of science both in explaining the world and in providing for people’s physical comfort has led to a situation in which for much of the public, statements are true to the extent that they are scientific. For people like Plantinga, it is already something of a defeat to have to defend their views in scientific terms.

In emphasizing pragmatism in this way, is there a danger that science is putting blinders on concerning the reality of supernatural design? Could it be that scientists are ignoring crucial evidence for supernatural design because of the methodological restrictions they put on themselves in their professional lives? The answer is no. The reason is that there is no such thing as evidence for the supernatural. There are only examples of phenomena that currently lack convincing naturalistic explanations. Such phenomena are the stock in trade of scientists. No changes in practice are necessary to make scientists pay attention to them.

To have compelling evidence for supernatural design, it would be necessary to find some phenomenon that is not merely unsolved, but one where there is good reason for believing it to be unsolvable, even in principle. ID proponents claim that such phenomena have been discovered, and they point to things like the origin of life or the complexity of the cell, to make their case. In their more exuberant moments they claim to be able to prove that there are certain phenomena in nature that simply cannot be explained without recourse to intelligent agents.

Scientists have considered the arguments made to defend this view and have found them to be utterly inadequate. It is not naturalistic blinders, but the emptiness of its assertions, that prevent ID from being accepted by scientists. There is no reason to believe that any of the open questions occupying scientists nowadays are of a sort that will forever resist naturalistic explanations.

Let us return now to the general question of whether assuming the reality of the supernatural can ever be useful to scientists. It is certainly true that many scientists in the past have been guided towards effective scientific theories as a result of their religious faith or their understanding of divine action. But this is neither here nor there. Scientists derive their inspirations from a multitude of sources, but this is wholly irrelevant to the subsequent verification of their ideas. Regardless of where an idea came from, it must pass through the ringer of experimental verification before it becomes part of science.

Are there other options? In his aforementioned essay, Alvin Plantinga argues that scientists who accept the Christian faith should integrate that faith into their work:

My main point, therefore, can be summarized as follows. According to Augustine, Kuyper, and many others, human history is dominated by a battle, a contest between the Civitas Dei and the City of Man. Part of the task of the Christian academic community is to discern the limits and lineaments of this contest, to see how it plays out in intellectual life generally, and to pursue the various areas of intellectual life as citizens of the Civitas Dei. This naturally suggests pursuing science using all that we know: what we know about God as well as what we know about his creation, and what we know by faith as well as what we know in other ways.

There is much to criticize in this paragraph. For example, the phrase “know by faith” seems oxymoronic to me. Instead, however, let me make a more general point.

There are plenty of people who share Plantinga’s view that Christian theism should inform the work that scientists do. If they want to be taken seriously, however, they must leave their armchairs, enter a laboratory, and demonstrate that their approach to science works better than the way it is currently done. The test is simple: Go discover something. Stop with the armchair theorizing, the whining about naturalistic bias, and the empty charges against well established branches of modern science. Instead, make progress on some problem that has stymied mainstream scientists.

If they succeed in this enterprise, their approach will be accepted. Otherwise, it will be rightly rejected. Everything else is irrelevant bluster.

And that brings us back to the original question. Is ID science? Not in its present form. Its central assertion is that an unfathomable intelligence took some unspecified action at some point in natural history. Since there is no hope of using that assertion to explain some formerly mysterious aspect of nature, it is plainly unscientific. On the other hand, many of ID’s assertions about the inadequacies of evolutionary theory, or about its ability to prove mathematically the intervention of an intelligent agent in natural history are, indeed, scientific. They are also demonstrably false, alas.

Any way you slice it, Intelligent Design offers nothing of value to professional scientists.


Jason Rosenhouse

Jason Rosenhouse is the author of EvolutionBlog, providing commentary on developments in the endless dispute between evolution and creationism.