Hybrid Warriors

What is it for something to be good? Aristotelian theory contends that to be good is to be good as a member of one''s kind, and so there are varying standards of goodness depending on whether something is a squirrel, human, or whatever kind. Appearing in several contemporary versions,1 the theory has the advantage of easily explaining, for instance, why having deep, broad roots is a measure of excellence for the oak tree but not for the squirrel, which has a different standard of goodness. Michael Thompson''s and Philippa Foot''s version of the Aristotelian account offers to give content to the kind-based standards, using the very conception of the kind of lifeform that an individual organism bears. It is perhaps a little noticed feature of Foot''s project, in particular, that it aims to provide more than just a kind-relative account, but seeks an exhaustive account of something''s goodness. She concludes, in effect, that something''s goodness admits of only the kind-based sort. Wha