 We began with a simple distinction between two concepts of liberty, and have progressed from this to the recognition that liberty might be defined in any number of ways, depending on how one interprets the three variables of agent, constraints, and purposes. Despite the utility of MacCallum’s triadic formula and its strong influence on analytic philosophers, however, Berlin’s distinction remains an important point of reference for discussions about the meaning and value of political and social freedom. Are these continued references to positive and negative freedom philosophically well-founded?