By Hendrik van der Breggen
The Carillon, February 23, 2012
God-of-the-gaps objection (Part 3 of 4):
Intelligent design has reasonable constraints
According to the God-of-the-gaps objection, science should not appeal to intelligent design (ID) to explain phenomena found in the natural realm. The concern is that ID will be applied inappropriately, filling gaps in our knowledge, gaps that science will explain via non-intelligent causes.
Philosopher David Hull warns, "Once [scientists] allow reference to God or miraculous forces to explain the first origin of life or the evolution of the human species, they have no way of limiting this sort of explanation." As biochemist Michael Behe observes, "There is the anxiety that if the supernatural were allowed as an explanation, then there would be no stopping it—it would be invoked frequently to explain many things that in reality have natural explanations."
In other words, at the heart of the God-of-the-gaps objection is the idea that the application of a hypothesis must be guided by reasonable constraints but, or so the objection goes, the ID hypothesis has none. Thus, we must always appeal to non-intelligent causes.
Last time I argued that the God-of-the-gaps objection fails because it is too strong. Always ruling out ID runs the risk of ignoring actual limits to what non-intelligent causes can in fact do, and thus we end up always appealing to non-intelligent causes when an intelligent cause actually produced the event or structure. The result: We assume the outcome of an investigation before the investigation takes place (which is, to put it mildly, closed minded).
The time before last time, I argued that the God-of-the-gaps objection fails because the application of ID is not an appeal to ignorance or gaps in our knowledge; rather, ID is an appeal to positive knowledge. ID is appropriately applied when, and only when, two conditions are satisfied: (1) we have positive knowledge that non-intelligent causes clearly struggle/fail, and (2) we have positive knowledge that the phenomena to be explained clearly resemble the sorts of things that only known intelligent causes do. In other words, and contrary to what the God-of-the-gaps objection would have us think, the application of ID is guided by reasonable constraints.
Today I will argue that ID has yet another reasonable constraint to guide its application, and this constraint weakens the God-of-the-gaps objection even further. (This constraint may be a bit more difficult to understand than the constraints I set out previously, so please bear with me.)
The additional constraint is this: In many sciences, explanations that appeal to intelligent agency constitute a syntactically/ categorically inappropriate response to the question motivating those sciences, so in these sciences an appeal to ID is inappropriate from the get go, whereas in other sciences ID is not inappropriate.
Philosopher of science Stephen C. Meyer explains the constraint well, so I will follow him closely (subsequent quotes are from Meyer).
Meyer points out that the sciences can be divided into two broad categories: historical and nonhistorical.
The nonhistorical sciences consist of branches of physics, chemistry, and biology, and are "concerned primarily with the discovery and explication of general phenomena." The goal of these sciences is to investigate the world's regular operations, i.e., "to discover, classify or explain [via] unchanging laws and properties of nature."
The historical sciences, on the other hand, consist of such sciences as historical geology, evolutionary biology, and archaeology. Their concern is "to reconstruct the past and explain the present by reference to the past," i.e., to "explain events or data not primarily by reference to laws but by reference to past causal events or sequences of events—what might be called 'causal histories.'"
Whereas Meyer uses the terms "nonhistorical science" and "historical science", some thinkers use the terms "operation science" and "origin science," respectively. Operation science has to do with the ongoing regularities of nature; origin science has to do with historical singularities or beginnings in nature.
Clearly, an appeal to intelligent agency is not always inappropriate in the historical sciences. In archaeology it makes sense to claim that an intelligent agent was the cause of what appears to be a cave painting. Also, in historical biology it makes sense to claim that an intelligent agent may have been the cause of life's origin. Of course, these claims might be false. However, with respect to the motivating questions of the historical sciences—i.e., questions of the sort "What is the cause of X?"—they are not logically inappropriate responses.
On the other hand, in the nonhistorical sciences an appeal to intelligent agency is logically inappropriate always. The answer "an intelligent agent did it" fails to respond correctly to the kind of question motivating the nonhistorical sciences. Nonhistorical sciences ask questions concerning how nature operates normally, i.e., how nature operates without the interference or special actions of intelligent agency (whether human or divine or alien), and so these sciences seek answers which involve the descriptive and/or explanatory use of natural laws and non-intelligent processes.
Meyer puts it this way: “To offer ‘God did it’ as an answer to a question such as ‘How does weightlessness generally affect crystal growth?’ clearly misses the point of the question. The answer does not so much violate the rules of science as the rules of grammar.”
Appeals to intelligent agency in the natural realm, then, are constrained by the fact that they are syntactically inappropriate in the nonhistorical or operational sciences. This means that as a possible causal answer in the doing of science, ID is limited primarily to the category of historical or origin sciences. Significantly, this constraint reduces the chances of applying ID erroneously.
Therefore, because the application of the ID hypothesis is guided by this additional reasonable constraint, i.e., the constraint that ID is to be applied only (if at all) to historical sciences, the God-of-the-gaps objection to the scientific legitimacy of ID (arising from ID's alleged lack of reasonable constraint) is additionally weakened.
Stay tuned for part 4.
P.S. My quotes from Stephen C. Meyer are from his essay "The Methodological Equivalence of Design and Descent," in The Creation Hypothesis: Scientific Evidence for an Intelligent Designer, edited by J. P. Moreland (Downers Grove, Illinois: InterVarsity Press, 1994), 67-112. Meyer restates these points in his book Signature in the Cell: DNA and the Evidence for Intelligent Design (New York: HarperCollins, 2009), 408-410.
Hendrik van der Breggen, PhD, is assistant professor of philosophy at Providence University College. The views in this column do not always reflect the views of Providence.