It is often claimed nowadays that “science”, by definition, can only invoke “natural” causes as explanations, where “natural” causes are restricted to entities or laws that will presumably find inclusion in a completed form of physics or to things that are either ontologically reducible to or strongly supervenient on such entities and laws. In short, according to this view “science” has to approach the world as a causally closed physical system. Let’s call this view strong metaphysical naturalism (SMN).
Now, I think this is the wrong way to define “science” for the reasons that I give here. But many people are apt to think that there is something right about SMN. After all, if we don’t place any restrictions on what types of explanations are permissible, then don’t we open the floodgates for all sorts of pseudo-scientific nonsense to masquerade as genuine science? How else could we exclude from science ‘magical’, paranormal, and miraculous explanations? Certainly a rational person ought to be very cautious if not downright skeptical about such explanations.
I’m very sympathetic to such concerns, but SMN is not the answer. So far as I can see, there’s nothing intrinsically wrong with magical, paranormal, or miraculous explanations. I certainly don’t want to rule out such things a priori on the off-chance that such explanations just might, on occasion, be correct. The problem with pseudo-scientists is not the types of explanations they propose but the fact that they invoke such explanations way too soon, before properly looking for and excluding the plausible alternatives. This leads to what I call weak methodological naturalism (WMN), which says that in science natural explanations are to be preferred over non-natural explanations unless there are no plausible natural explanations and there is good reason to think that no plausible natural explanation will be forthcoming.
The basic idea behind WMN has been captured by ID-theorist William Dembski in what he calls the ‘explanatory filter’: “Roughly speaking the filter asks three questions and in the following order: (1) Does a law explain it? (2) Does chance explain it? (3) Does design explain it?” Thus, explanations in terms of deterministic or stochastic natural laws need to be ruled out (i.e., shown to be implausible) before it is reasonable to appeal to chance or luck, and chance needs to be ruled out before it is reasonable to appeal to design. And, extending this further, it seems to me that appeals to little ‘d’ designers ought to be ruled out before we are justified in appealing to a transcendent Designer-God. In short, there’s an appropriate epistemological order of explanation that good scientific methodology will respect. Miracle-type hypotheses are not ruled out a priori, but they do face a stiff burden of proof.
Hi, Alan. I’m thoroughly enjoying your blog.
I disagree with you here. It seems like WMN is nothing more than throwing God the bones that Science has passed over. It buys into a false dichotomy between physical and metaphysical — the incorrect ideas that (1) if we can explain it naturally, then God is not required and (2) if we cannot (currently) explain it naturally, then God must have done it.
Not being a theologian or a scientist, I’m a bit out of my depth with this statement, but I’ll proffer it anway: Neither scripture nor science support this view. Scripture speaks as though all phenomena, no matter how explainable, are under God’s control (rain, the sun, the birds finding food); and the progress of scientific knowledge does not support the idea that there are some mysteries for which we will never discover a physical explanation.
Hi Jeremiah,
I appreciate your concerns. Let me see if I can clarify my position in a way that helps.
When trying to explain any phenomenon what we’re ultimately looking for is the best explanation for it. Dembski’s idea is that there are three basic types of explanation: law, chance, and design. Which type of explanation is the best in a given instance? Well, that depends on things like theoretical simplicity, coherence with background knowledge, its predictiveness (i.e., Prob(explanandum | explanans)), and so forth.
Now, with respect to predictiveness, lawlike explanations are almost invariably stronger than design-type explanations, unless the design explanation is fleshed out to the point where it starts to suffer on grounds of theoretical simplicity. Similar considerations hold with respect to chance vis-a-vis law and design. What this means is that, all other things being equal, lawlike explanations are generally superior to chance explanations which in turn are generally better than design explanations. This is what gives rise to the explanatory filter. Note, however, that even when a lawlike explanation comes out on top, that doesn’t rule out any role for chance and/or design. But it does undercut one’s positive grounds for appealing to chance and/or design. For a chance or a design explanation to come out on top, then, it has to distinguish itself in some way as the best. While normally less predictive or less simple than its lawlike competitor, a design-type explanation may fit so much better with our background knowledge that it is clearly the best explanation overall. In short, then, determine which explanation is best in any given situation requires finding the optimum balance among often competing explanatory desiderata.
This is not “throwing God the bones that Science has passed over” but rather applying commonsense evaluative criteria to determine when invoking God as an explanation is the most scientific thing to do. Finally, bear in mind that I’ve only been talking about the search for a certain kind of explanation–what’s often called an event-causal explanation (how did event E or state of affairs S come about?). That does not at all preclude the possibility of there being other types of explanations, like metaphysical explanations for the continuing existence of the physical universe as a whole. So even if we can give a fully adequate locally naturalistic story of how E came about, that doesn’t mean that God didn’t have anything to do with it.