CONFUSION IN PHILOSOPHY - A COMMENT ON WILLIAMS (1992)

Patricia Williams made a number of claims concerning the methods and p ractise of cladistic analysis and classification. Her argument rests u pon the distinction of two kinds of hierarchy: a 'divisional hierarchy ' depicting 'evolutionary' descent and the Linnean hierarchy describin g taxonomic groups in a classification. Williams goes on to outline fi ve problems with cladistics that lead her to the conclusion that syste matists should ''eliminate cladism as a school of biological taxonomy and to replace it either with something that is philosophically cohere nt or to replace it with 'pure' methodology, untainted by theory'' (Wi lliams 1992, 151). Williams makes a number of points which she feels c ollectively add up to insurmountable problems for cladistics. We exami ne Williams' views concerning the 'two hierarchies' and consider what cladists currently understand about the status of ancestors. We will d emonstrate that Williams has seriously misunderstood many modern comme ntators on this subject and all of her ''five persistent problems'' ar e derivable from this misunderstanding.