To clarify why I found Williamson’s and Rosenberg’s definition of naturalism so unsatisfying, let’s look at the former’s definition of the scientific method:
What is meant by “the scientific method”? Why assume that science only has one method? For naturalists, although natural sciences like physics and biology differ from each other in specific ways, at a sufficiently abstract level they all count as using a single general method. It involves formulating theoretical hypotheses and testing their predictions against systematic observation and controlled experiment. This is called the hypothetico-deductive method.
What does it mean to make a systematic observation? How about controlled experiment? These words are vague and imprecise, and can mean different things to physicists and psychologists. They can even mean different things to space physicists and atomic physicists. Systematic isn’t really possible when solar and magnetic field conditions change continuously, but can be if the entire experiment is run on a lab bench.
The discussion would have been much richer if they spent some time (dare I say it?) deconstructing these terms. Even at a “sufficiently abstract level” it’s not clear how to lump particle physics and observational ecology under a single general method. As I’ve said repeatedly, the various branches of science are disunified and heterogeneous.
Granted, these were relatively short blog posts and not a dissertation on naturalism. But given my longstanding desire to disaggregate science and demonstrate its intense diversity, I’m always disappointed when writers whose blogs are more widely read than mine don’t explore these themes.