Abstract

It is argued that the moral theory undergirding J.S. Mill''s argumentin On Liberty is a species of perfectionism rather than any kind of utilitarianism. The conception of human flourishing that itinvokes is one in which the goods of personal autonomy and individualityare central. If this conception is to be more than the expression ofa particular cultural ideal it needs the support of an empiricallyplausible view of human nature and a defensible interpretation ofhistory. Neither of these can be found in Mill. Six traditionalcriticisms of Mill''s argument are assessed. It is concluded thatin addition to depending on implausible claims about human natureand history Mill''s conception of the good contains disablingincommensurabilities. It is argued that these difficulties andincommensurabilities plague later liberal thinkers such as IsaiahBerlin and Joseph Raz who have sought to ground liberalism in avalue-pluralist ethical theory. No thinker in Mill''s liberal posterity has been able to demonstrate the universal authority of liberal ideals