Unfortunately, most people do not think scientifically or even logically, and the rhetoric of politicians and salesman commonly banks on this fact. To take a Black Swan example, consider how easily the difference between “Most terrorists are Muslims” and “Most Muslims are terrorists” is overlooked by the public in discussions of foreign and domestic social policy. Or consider how often you have heard the words “science has proven”, “scholars say”, and “studies show that”, without any consideration of how it was proven or which scholars say. Public discussion of scientific topics, especially when surrounding controversy, is commonly littered with empty appeals to authority and ad hominem argumentation: “Well biologist A, who works at prestigious university X has concluded after years of research that Y; therefore, I trust his/her word over yours,” or “You mean to tell me that human inputs to the atmosphere are partially responsible for climate change? Don’t tell me how it works, just tell me whether you’re receiving grant money from the government!” These tactics may work well to convince a jury, but they do not constitute critical thinking.
Perhaps, I should return to the original question and phrase it this way: is ‘science’ a noun or a verb? Is it something that is, or something that is done? I am not concerned here about dictionary definitions, semantic ranges, or etymology; rather, I want to elucidate the meaning of science in practice and its limitations. In other words, my goal is not to offer a comprehensive discussion of the scientific method throughout history, nor to lecture anyone about what I think science is. Instead, I want to simply show how science is the active pursuit of knowledge about the natural world, and is guided by an epistemological framework outside the realm of science itself.
My inspiration for this post comes from a recent article, by Roger Patterson at Answers in Genesis, entitled “What is science?” There, Mr. Patterson discusses the history of scientific thought, the difference between various types of scientific approaches, and how this relates to the study of Earth history. Since his aim is to defend the validity of Creation science and the Young-Earth interpretation of geological data, you may not find it surprising that I disagree with some of his comments and conclusions. However, I applaud his willingness to define the scope and methods of science from a young-Earth perspective, and would not dismiss the discussion wholesale. So I don’t expect to provide a rebuttal here so much as a discourse guided by the points he has already made.
The scientific method and categories of science
The scientific method is a process built around falsifying hypotheses, which are formulated from observations of the natural world (note: natural as opposed to supernatural or metaphysical; not as opposed to artificial). Let’s say you wanted to investigate the reason behind different yields from the same crop grown in two different regions. Your observations may include the actual crop yield, temperature and precipitation records, soil samples, etc., from which you can formulate a hypothesis such as: “Crop yield is a direct function of rainfall.” Sounds good, right?
While the explanation sounds plausible, especially if the region with higher yield receives significantly more precipitation and given that plants need water for growth, it is by no means proven. Science is much more than building plausible-sounding arguments! One must first demonstrate a correlation between rainfall and crop yield by falsifying the null hypothesis: “Crop yield is not a function of rainfall.” The falsification may require more observations or a controlled experiment to obtain statistical significance, which means that some uncertainty is involved. Furthermore, a statistical correlation may be consistent with the original hypothesis, but does not itself prove it. One must also falsify alternative explanations for the same phenomenon; in this case, the dependence of yield on nutrient availability, soil type, solar irradiance, etc. For the hypothesis to remain scientific, it must also remain predictive of new facts (such as crop yield in regions C, D, E, etc., for a given amount of rainfall in the respective regions).
When a scientific hypothesis can predict new data, rather than being falsified thereby, it is treated as true (i.e. proven), but only provisionally so. The reason is that scientific hypotheses can only address existing data and are potentially falsifiable. Furthermore, scientific hypotheses are built (dependent) on a range of other scientific theories, which themselves remain only provisionally true. In this sense, a scientific premise may be proven and accepted as true, without any claim of infallibility. Considering the contingent nature of scientific conclusions, one may be inclined toward skepticism. However, one should also remember that the scientific method is self-correcting, since hypotheses not corresponding to reality are quickly falsified when tested by multiple independent researchers.
Philosophers of science typically make some distinction between experimental and historical methods of science (if you recall, I discussed historical science at length in a previous article). Since science must address a wide range of phenomenon (from molecular interactions to planetary motions; from modern world economies to human history; etc.), researchers may further refine the method according to their respective disciplines. Mr. Patterson describes the essential difference as following:
This is a point on which I sincerely disagree, and I think it is an unfortunate caricature that only promulgates the misguided and unnecessary dichotomy between “Old-Earth Naturalism” and “Young-Earth Christianity”, and between science and religion in general. First, unraveling the message of the Bible (especially as it pertains to history) is a matter of exegesis, which is in itself a hermeneutical science. Mr. Patterson or anyone else can argue for the validity of their reading of scripture above all others, but it is unfair and inaccurate to state that an acceptance of the Bible as God’s witness precludes evolutionary theory (or any scientific theory, for that matter) from the interpretive framework. That assertion is a working hypothesis in competition with others, and is contingent upon the facts of linguistic theory, textual criticism, etc. As such, it is also potentially falsifiable. Secondly, the theory of evolution does not deny the role of God in the universe. Science operates under methodological naturalism, which means that it can only investigate natural explanations for natural phenomenon. By definition, the act of special creation (if defined as the sudden appearance or organization of matter by supernatural forces) is excluded from direct scientific investigation. Science does not, by definition, deny its truth, but is rather, by definition, silent on the matter. On the other hand, one can produce testable hypotheses in biology, geology, astronomy, etc. given a starting belief in special creation and a young Earth. In this sense, science could investigate the issue indirectly. Thus it is inaccurate to say “the denial of supernatural events limits the depth of understanding that science can have and the types of questions science can ask,” as Mr. Patterson asserts later. Starting with a belief in God that providentially oversees the natural world does not change the scope or nature of scientific questions we can ask, since science is still limited by methodological naturalism. Theoretically, science could determine that all modern species appeared abruptly within the last 10,000 years, but science would still be silent on whether one God or millions of gods were responsible, and the personal character thereof. Taking an example from Mr. Patterson, let’s consider this in practice:
Mr. Patterson reflects a common sentiment, which provides a powerful talking point in the discussion. At first, it appears the categorical limits of science prevent us from an unbiased assessment of nature. However, intrinsic to his argument is the premise that at some degree of observed complexity in organisms, we must conclude that the organism could not have arisen through “natural” processes. But how do we define that level of complexity? Some authors have made a case for biological features that are irreducibly complex, but keep in mind two things: 1) the identification of features as irreducibly complex is contingent on the existing data, and is potentially falsifiable in light of new observations; 2) even if the label can withstand new observations, it does not logically follow that the feature “must have a designer”; rather, we would only establish that to date, no known natural process can account for this feature. Remember that all science, regardless of one’s philosophical commitments, is methodologically naturalistic (i.e. excludes supernatural explanations in practice). Thus “naturalistic science”—that is, science practiced by one who is a naturalist/materialist, according to Mr. Patterson—is not alone in excluding such a conclusion from the scientific investigation.
On what is natural
Before I sound as though I am contradicting myself, I want to clarify why I am comfortable, as a Christian, excluding design arguments from science. If one believes that a personal God is responsible for the existence of time, matter, and space, then it follows that everything is designed in the sense that every material instance has a purpose. In other words, the teleological principle is part of our a priori philosophical commitment to theism. As such, it cannot be the object of scientific investigation, which itself is built on principles of philosophy. Science cannot demonstrate design in nature any more than it can demonstrate the uniformity of natural laws; both are preconditions for knowledge about the natural world, while the former is unique to theistic worldviews.
My advice to Mr. Patterson, and anyone that supports the Intelligent Design (ID) movement, is to focus on exploring God’s creation without attempting to redefine the scope of the scientific method. With the exception of Dembski’s work, much of the ID movement’s interaction with the public is somewhat misguided, and only results in equally misguided responses from critics of theism, such as Dawkins’ examples of “bad design” (note: the word “intelligent” in ID is not meant to be contrasted with “stupid”, but simply with “non-intelligent”; examples of “bad design” from Dawkins and others constitute interesting facts about nature, but are wasted efforts as arguments against ID).
Falsification and scientific theories
I mentioned earlier that the scientific method is built around falsification of hypotheses. The work of Karl Popper (and his critics) with regard to science as falsification has remained canonical through scientific disciplines. He argued that testability (the ability to prove wrong) is the key criterion for calling a study scientific. However, defining the criteria by which a hypothesis can be falsified is not always a simple, straightforward process. Most scientific theories/hypotheses have been modified numerous times in response to contrary evidence from previous experiments. Granted, this typically results in the ‘self-correcting’ aspect of science and a refinement of good scientific theories, but elucidates how bad theories can live beyond their years if supported by a stubborn, false paradigm (e.g. consider Kuhn’s discussion of scientific revolutions). So how does this relate to the creation/evolution controversy? Mr. Patterson writes:
The fact that past events, such as the appearance of new species, cannot be repeated does not disqualify a theory from being scientific. When anthropologists/archaeologists excavate an ancient city, the response is hardly “Well, time to leave science at the door. Put on your guesswork hats!” The reason is that hypotheses about past events can be tested (i.e. falsified) by remaining evidence. In the case of evolution, there are numerous ways to falsify the theory: demonstrate that species share no vestigial remnants from a common lineage; demonstrate that all species appeared abruptly and coincidentally; demonstrate the existence of a predicted descendant taxon long before the existence of a predicted ancestral taxon (e.g. the existence of birds and theropods before crocodilia, which is the predicted common ancestor). By the same line of reasoning, Mr. Patterson’s interpretation of the creation story can be tested scientifically, in that one can seek to falsify the hypothesis of a global flood, abrupt and distinct appearance of species/genera, and more. In fact, that is one major goal of my blog: to consider whether predictions stemming from the young-Earth model have not already been falsified. Theological details of the young-Earth model lie outside the scope of scientific investigation; historical events associated therewith, however, do not.
Uniformitarianism: a principle of geology; not ‘that other church’ around the corner
A longer discussion of uniformitarianism is warranted at some time, but I will conclude here with a few comments on Mr. Patterson’s claims (for those interested in a detailed discussion of uniformitarianism, I strongly suggest reading Davis A. Young’s chapter in The Bible, Rocks, and Time). I am sure that all of you are familiar with the basics of historical investigation, namely that we can use present facts to interpret past events. This applies to geology as well as human history, the former of which is built on the principle of uniformitarianism. In addition to the assumption that physical constants and laws (e.g. the speed of light, gravity, etc.) were unchanged through history, uniformitarianism is basically just an extension of Occam’s Razor, which states that complexity should not be posited without necessity. In other words, we interpret past geological events in light of known, modern events, unless there is evidence to the contrary. With that in mind, consider Mr. Patterson’s assessment:
By “evolution”, Mr. Patterson is also referring to geologists that reject the notion of a young Earth. It is true that the principle of uniformitarianism has commonly been summarized as “the present is the key to the past”, but the description is not exhaustive and Mr. Patterson takes advantage of this fact. He is mistaken in saying that “uniformitarians” believe modern processes have ensued at a “relatively constant rate.” Such is a caricature, since no modern geologist would state this a priori. Rates of erosion and rock formation, for example, are determined by geological evidences. Evidence is collected by testing hypotheses generated from observations and/or scientific models of the process. Rates of sedimentation are never simply assumed to be slow or fast. One only needs to search publications on sedimentology and stratigraphy to see that interpreted rates of deposition range over several orders of magnitude (consider the difference between sediments accumulating 1) onto the deep ocean floor, 2) the Mississippi River floodplain, and 3) near the continental slope by means of tectonically driven landslides). However, Mr. Patterson seems to think that catastrophes like Noah’s flood are excluded from scientific investigations because of philosophical commitments. On the contrary, many such catastrophes have been interpreted from the geological record and are widely accepted (large-scale floods, meteor impacts, massive lava flows and landslides, etc.). The problem is that most sedimentary layers do in fact show good evidence for slow deposition. He states, “Noah’s Flood, for example, would have devastated the face of the earth and created a landscape of billions of dead things buried in layers of rock, which is exactly what we see.” Any geologist would agree that Noah’s flood might be expected to leave layers of fossiliferous rocks. Detailed examination of those fossiliferous rock layers reveals they were not the consequence of multiple stages of a single, short-lived event, however, but millions of events over millions of years.
The philosophy of science is a difficult subject, since the criteria by which a theory may be deemed scientific are open for discussion. One of the most fundamental and stable of these criteria is testability, or falsification. Mr. Patterson agrees with this criterion, but attempts to distinguish historical science from “operational science” to the extent that he may subject evolutionary theory and historical geology to unwarranted skepticism among his audience. In doing so, he undermines the validity of other historical inquiries, such as the textual transmission of the Bible and historical reality of the New Testament referents, which are undoubtedly important to Mr. Patterson’s (and my own) worldview. A faithful application of the scientific method does not render the works of God silent, but results in an efficient, self-correcting means of exploring the details of His masterpiece. I would compare this to the relationship between an artist’s mind and the painting, the latter of which was created through a variety of physical processes. One may examine the character of brush strokes, chemistry of the paint, geometry of objects, etc. to determine how the picture was made without consideration of why. An art critic may still ask the “why” questions, but through a very different method.
Science is the active pursuit of knowledge about the natural world. As such, it is methodologically naturalistic, and cannot speak to facts outside the realm of empirical observation. However, the scientific method is one epistemological method among others in the grand scheme of philosophy, and therein rests on principals not subject to scientific inquiry. This categorical distinction should humble the scientific researcher, who, if ignorant of such, is but “a man with his feet firmly planted in midair,” to cite the words of Schaeffer.