Abstract

Ethical extensionism generally involves drawing one or more lines of moral standing. I argue for all living organisms, there is a non- zero probability of sentience and consciousness, and we cannot justify excluding beings from consideration on the basis of uncertainty of their sentience, etc., and rather we should incorporate this uncertainty into the strength of our moral responsibilities. This use of probabilities differs critically from multi-criteria theories of moral standing and those that assign benefit of the doubt, which involve unjustified exclusions and dilutions of duties. From uncertainty rises certainty : we have duties to non-human organisms, although they may often be minor. This modification of extensionist ethics provides foundation for an environmental ethic that parallels interpersonal and animal welfare ethics, and it suggests that we owe much greater concern to 'lower' organisms than they are typically given.