Abstract
A central thesis of biocentrism is that all living things have intrinsic value. But when conflicts arise between the interests of humans and other organisms, this claim often has counterintuitive consequences. It would be wrong, for example, to swat pesky flies. Some biocentrists have responded by positing a taxonomy of interests in which human interests justifiably supersede those of other living things. I express doubts about whether this maneuver can succeed, and suggest that even if it does, it then commits biocentrists to the claim that it is wrong not to harm living things, when doing so is necessary to advance nonbasic human interests, a position which runs counter to the biocentric attitude of respect for nature. As a result, biocentrists must adopt either a highly counterintuitive position or one that is contrary to their general outlook. I show that the introduction of the supererogatory may resolve not only this biocentric dilemma but other quandaries in environmental ethics.