Abstract

This paper explores the notion of species-relative critical levels, which is a crucial ethical issue in multi-species population ethics. First, the formal conditions are provided under which there are species-relative critical levels (e.g., the critical level for human beings is different from that for non-human beings). In particular, we find it a salient question of animal ethics whether the existence of a human being is morally better than that of a non-human animal when their utility levels are the same. Subsequently, we illustrate two general classes of multi-species critical-level utilitarian orderings. One class employs species-relative critical levels, which entails either the animal repugnant conclusion or the animal sadistic conclusion. The other employs species-relative critical levels plus species-lexical ordering. Although it can avoid both the animal repugnant conclusion and the animal sadistic conclusions, it has the problem of speciesism.