Burden of proof lies with proposer of celestial teapot hypothesis

Abstract

Bertrand Russell famously imagined the existence of a celestial to highlight that the burden of proof of a hypothesis lay with its proposer and it was not the responsibility of others to refute it. Those who propose that fish feel pain must bear the burden of proof for their hypothesis. There are several common arguments adopted by those defending the position that fish feel pain. For instance, proponents envisage that pain is so important for human survival that they can’t imagine fish could exist without it. Out of this argument from incredulity emerges the idea that pain must have evolved early in animal evolution ergo fish feel pain. Fish pain proponents often accept that fish might feel pain because it seems highly probable that fish do. Similarly it is reasoned that if fish seem to display multiple human-like characteristics (such as complex behaviours, learning and tool use), then they must be intelligent and hence make it more likely than not that they feel pain. It has been argued that those who accept the null hypothesis that fish do not feel pain are merely cherry picking the literature to refute fish pain. These claims are levied without understanding that the strength of inferences is heavily influenced by the robustness of the data and the nature of the results. The fallback position that fish pain proponents adopt when they accept that the fish forebrain does not generate pain is to suggest that fish pain arises from somewhere else in the brain using different circuitry. In the case of the present commentaries the brainstem is recognised as the seat of pain in fish. Although it is not the responsibility of the non-proposer of this “celestial teapot to refute it, I provide evidence that makes continued adoption of this stance untenable.