Professor Macpherson is perhaps the most important living heir of John Stuart Mill and more especially of that in Mill which in the latter part of his life led him to become a socialist. Macpherson's polemics against liberalism's inheritance from possessive individualism make him the opponent of some of Mill's substantive positions and of even more of his formulations. But if we represent Macpherson as trying to rescue from Mill that which derives from his “concept of the power of a man as his ability to use and develop his uniquely human capacities” from that which derives from his “concept of a man's power as his ability to command the services of others” (Democratic Theory, henceforth DT, p. 79) we shall do him no injustice. If he disagrees with Mill and Berlin in his rejection of any purely negative concept of liberty, he agrees with them in rejecting what he calls the “Idealist or metaphysical rationalist” view of positive liberty with its “great, disciplined, authoritarian structures” (Berlin's phrase).