I’d be interested in hearing what our readers think of Timothy Williamson’s case against naturalism in this post at the NYT’s Stone blog (H/T NewApps). As I read it, his argument has the form of a dilemma. There are, he supposes, two ways that the thesis of naturalism can be defined:
- Naturalism might be the ontological thesis that the only things that exist are things of some sort.
- Naturalism might be the methodological thesis that the scientific method is the only legitimate method of finding out what there is.
If the naturalist adopts characterization (1), then Williamson’s response is that there is no adequate way to characterize the relevant “sort” of things: if the naturalist simply says that she means that there are only natural (or non-super-natural) things, then her definition is circular, and if she tries to give a more substantial characterization, then she is likely to be out of step with present or future science. There is then a natural temptation to move in the direction of characterization (2), perhaps defining the relevant sort of entities as the sort that science postulates. But this characterization is problematic unless there is an answer to the demarcation problem (i.e. the problem of drawing the line between science and non-science), and finding such an answer has proven to be rather difficult, to say the very least.
It should be noted that there is a large and ever-growing philosophical literature on these issues, and many believe that challenges like this can be resisted. It is nice, though, to have the matter summed up so succinctly. So what do you think? Are you a naturalist? If so, how do you respond to Williamson’s challenge?
P.S. One other thing to note here is that there are some forms of philosophical naturalism that aren’t harmed by this criticism, but only because they’re views of how to do philosophy, rather than views about what there is. For example, I am quite sympathetic with the idea that the methods of philosophy aren’t entirely discontinuous from those of the natural sciences (I’d call this “Quinean naturalism”, except that Quine was also a naturalist in the senses of (1) and (2)), and I have argued in my own work that the conclusions of apparently sound a priori arguments can be challenged on empirical grounds. At the same time, though, I think that philosophical theorizing has a place of its own, especially in places where experimental evidence isn’t (or, perhaps, can’t be) available. That is, I agree with Williamson when he says this:
The scientific spirit is as relevant in mathematics, history, philosophy
and elsewhere as in natural science. Where experimentation is the
likeliest way to answer a question correctly, the scientific spirit
calls for the experiments to be done; where other methods — mathematical
proof, archival research, philosophical reasoning — are more relevant
it calls for them instead. Although the methods of natural science could
beneficially be applied more widely than they have been so far, the
default assumption must be that the practitioners of a well-established
discipline know what they are doing, and use the available methods most
appropriate for answering its questions. Exceptions may result from a
conservative tradition, or one that does not value the scientific
spirit. Still, impatience with all methods except those of natural
science is a poor basis on which to identify those exceptions.
In this sense, however, the scientific spirit is not restricted to (what is usually called) “science”, nor is it prejudicial against the existence of entities of any sort, no matter how “unnatural”.