  The question about the extent to which the existing moral disagreement is radical is essentially an empirical one. Yet references in the philosophical discussion to the numerous studies by anthropologists, historians, psychologists and sociologists who have documented the disagreement are relatively  sparse.[2] This may seem regrettable, and some have accordingly emphasized that philosophers should pay more attention to empirical research (see, e.g., Sturgeon 1994, 230 and Loeb 1998, 284). That is surely good advice, but the absence of references to the empirical literature is also to some extent understandable.