•Current controversies about the definitions of taxon names reflect different underlying philosophical perspectives concerning the nature of definitions. The antithetical perspectives, called methodological essentialism and methodological nominalism (Popper, 1966, The open society and its enemies, Princeton Univ. Press, Princeton, NJ), are exemplified by alternative views in a controversy surro...

Wbatever its merit as an account of political institutions, the social contract theory bas, in recent years, been the subject of intense scrutiny as an explanation for our moral obligations. Prominent examples of this approacb include the work of Jobn Rawls and David Gauthier. l A criticism of this understanding ofmoral obligation arises from several commentators, partly as a result of claims m...