The question of whether fish consciously feel pain cannot be settled by looking for the same neural mechanisms that underlie human pain reports. Non-mammalian consciousness, if it exists, may rely on different mechanisms. Neurophysiological and behavioral evidence, evolutionary considerations, and Bayesian brain theories suggest that if fish can feel at all, they can feel pain. Because pain and suffering are qualitative experiences, the precautionary principle obliges us to accommodate the possibility that fish feel pain where doubt remains.
Klein & Barron's proposal that insects may have phenomenal consciousness challenges the cautious stance of many researchers. While the skeptical view that neural and behavioral parallels between humans and insects need not imply conscious experience cannot be falsified, if Klein & Barron are correct, it is important to consider the possible contents of insect consciousness. This discussion explores whether affective consciousness, with its implications for potential suffering, might also be part of the simulated perceptual conscious world they propose. In humans, affect-induced modulation of decision-making leads to cognitive bias, and the question is raised whether this can be observed in animals and used as a novel indicator of animal affect and welfare.
David Peña-Guzmán argues against the claim that only humans can commit suicide because only humans have free will, offering two reasons: nonhuman animals may possess free will, and the libertarian concept of free will conflicts with scientific explanation. While the objection to restricting suicide to humans is correct, his critique of libertarian free will is misdirected; the real issues are the assumptions that free choices require conscious self-reflection or that freedom cannot vary in degree.