What was really wrong (and right) with vitalism? Methodological naturalism, organicism and immaterialist theories in biology

There has been considerable discussion in recent years of methodological naturalism in the sciences: the question of whether science does, or should, operate under the assumption that it may only investigate natural phenomena or offer natural explanations, and what form this assumption does or should take. Most of the discussion has centred around theories such as intelligent design creationism, but in this paper I argue that vitalism in biology-an immaterialist theory of living systems-provides an instructive and under-utilised test-case for methodological naturalism. I focus on three views: intrinsic methodological naturalism, provisional/pragmatic methodological naturalism, and, in particular, the 'unintelligibility' view I have previously defended: views which have not, for the most part, been applied to vitalism. The unintelligibility view comes in a metaphysical, and an epistemic form. I suggest that on the epistemic interpretation theories such as vitalism should be understood along the lines of 'mysterian' or 'ignorance' accounts of consciousness, and that this provides an illuminating account both of vitalism itself, and of its relationship to organicism in biology.