 For the most part, this focus is due to contemporary debates regarding the question of whether the concept of race is philosophically and scientifically defensible. Thus, work suggesting the removal of racial identifiers on donor catalogues seems to owe a great deal to authors such as K. Anthony Appiah (1995, 1996) and Naomi Zack (1993, 2002) who both deny that race is a coherent concept and recommend discarding it entirely (see the entry on  race).