In this chapter we turn to consider the first substantive issue that the case for ecological justice has to address, which concerns whether or not the granting of moral status to non-human organisms should be restricted only to that subsection of them which possess sentience. Ironically, some of the most persuasive philosophers who offer arguments for granting moral considerability to sentient non-humans are also among the most resolute in defending the view that sentience marks the limit of moral considerability. Two such authors are David DeGrazia and Peter Singer.
David DeGrazia's book does an excellent job of arguing that all sentient organisms matter, morally speaking. He pleads for a 'principle of equal consideration' extended to non-human animals (DeGrazia 1996:44-74), while at pains to emphasize that such a principle 'does not entail (1) identical rights for humans and animals, (2) a moral requirement to treat humans and animals equally, or (3) the absence of any morally interesting differences between animals and humans' (ibid.: 37-8). His arguments take full account of the most powerful earlier theories in this area, including the well-known and influential views of Singer (1990) and Regan (1983), and conceivably do a much more thorough job than do those authors of grounding the case for the moral considerability of sentient organisms in a detailed analysis of those organisms' mentality. His meta-ethical position is that of Rawlsian reflective equilibrium (DeGrazia 1996:12-14), which has the great advantage of avoiding the difficulties of foundationalism in ethics by locating moral thought within a holistic framework, but, as we will discover, has the disadvantage that some moral judgements are rejected on somewhat vague grounds, such as their not being readily fitted into the total view.
There is no space here to offer a detailed exposition of all DeGrazia's arguments. However, it will be useful to outline those which have a direct bearing on the topic of ecological justice. Firstly, the all-important 'principle of equal consideration' for non-human animals is intended to rule out a 'general discounting of animals' interests' (DeGrazia 1996:46). That is, for example, the counting less of a non-