Critics of intelligent design argue that intelligent design is not a scientific theory. They do so, however, not by confronting the evidence and logic by which design theorists argue for their conclusions. Rather, they do so by definitional fiat. Essentially, they engage in conceptual gerrymandering, carefully defining science so that conventional evolutionary theory falls within science and intelligent design falls without. This device typically goes by the name of methodological naturalism or methodological materialism. Eugenie Scott, director of the evolution watchdog group the National Center for Science Education (NCSE), describes methodological materialism as follows:
Most scientists today require that science be carried out according to the rule of methodological materialism: to explain the natural world scientifically, scientists must restrict themselves only to material causes (to matter, energy, and their interaction). There is a practical reason for this restriction: it works. By continuing to seek natural explanations for how the world works, we have been able to find them. If supernatural explanations are allowed, they will discourage — or at least delay — the discovery of natural explanations, and we will understand less about the universe.Eugenie C. Scott, Christianity, “Science and Religion”, “Christian Scholarship”, and “Theistic Science”: Some Comparisons at NCSE
There are two problems with this statement. First, if methodological materialism is merely a working hypothesis that scientists employ because “it works,” then scientists are free to discard it when it no longer works. Design theorists contend that for adequately explaining biological complexity, methodological materialism fails and rightly needs to be discarded. Second, and more significantly, in defining science as the search for natural explanations, Scott presupposes precisely what must be demonstrated. If, by natural explanations, Scott simply means explanations that explain what is happening in nature, there would be no problem, and intelligent design would constitute a perfectly good natural explanation of biological complexity. But that is not what she means.
By natural explanations, Scott means explanations that resort only to material causes — as she puts it, to “matter, energy, and their interaction.” But that is precisely the point at issue, namely, whether nature operates exclusively by such causes. If nature contains a richer set of causes than purely material causes, then intelligent design is a live possibility and methodological materialism will misread physical reality. Note, also, that to contrast natural explanations with supernatural explanations further obscures this crucial point. Supernatural explanations typically denote explanations that invoke miracles and cannot be understood scientifically. But explanations that call upon intelligent causes require no miracles and give no evidence of being reducible to Scott’s trio of “matter, energy, and their interaction.” Indeed, design theorists argue that intelligent causation is perfectly natural provided that nature is understood aright.