The idea that human beings have a distinct moral worth-a moral significance over and above any moral worth, such as that may be, possessed by other animals-has a long history and has traditionally been taken for granted by philosophers and theologians. However, in a variety of quarters in recent philosophy, this idea has come into disrepute, seeming to indicate a mere prejudice in favour of our own species. For example, Peter Singer has argued that such a position is mere speciesism, a prejudice of a kind with racism and sexism in that it involves making moral distinctions between our own and other species that cannot be morally justified. What on such views is needed to justify any such distinction is a difference in terms of the morally relevant properties possessed by our own species as compared with other species. I will call this view the moral property view. Insofar as other species share with us morally relevant properties, for example the capacity to suffer cognitive ability and so on, it is mere prejudice not to accept moral requirements with respect to them as we do with respect to our own species. While on the surface such a view may seem morally enlightened, it indicates what will seem to many problematic moral judgments with respect to severely disabled human beings. In this paper, I will respond to these concerns by suggesting a different basis for the idea of human moral distinctiveness, one that draws on recent work by Wittgensteinian moral philosophers and which denies what I called above the property view. According to this view, while our shared life with other animals involves the recognition of their moral significance, our shared life with other human beings involves recognising that human beings as human beings have a distinctive moral value.
