The curious case of the decapitated frog: on experiment and philosophy

Physiologists have long known that some vertebrates can survive for months without a brain. This phenomenon attracted limited attention until the nineteenth century when a series of experiments on living, decapitated frogs ignited a controversy about consciousness. Pflüger demonstrated that such creatures do not just exhibit reflexes; they also perform purposive behaviours. Suppose one thinks, along with Pflüger's ally Lewes, that purposive behaviour is a mark of consciousness. Then one must count a decapitated frog as conscious. If one rejects this mark, one can avoid saying peculiar things about decapitated animals. But as Huxley showed, this position leads quickly to epiphenomenalism. The dispute long remained stalemated because it rested on conflicting sets of intuitions that were each compatible with the growing body of experiments. What eventually resolved it is that one set of intuitions supported a research programme in physiology that came to seem more fruitful on the whole. So my case study suggests an alternative model for experimental philosophy as compared with more recent practice. Rather than using experiment to bolster our philosophical intuitions directly, we should explore how our philosophical intuitions might bolster (or block) fruitful experimental inquiry in science.