"This book is, unquestionably, the best available account of the literature on the philosophical foundations of modern libertarianism. Mack, himself a major contributor to that literature, carefully tracks its historical origins and offers an impressively acute analysis of the works of libertarianism’s leading contemporary exponents."—Hillel Steiner, University of Manchester"Eric Mack is at once one of the gentlest but also one of the most probing critics our profession has ever seen. His reconstructions are works of art, even when he ultimately disagrees. Mack has been as good as it gets for a very long time, and this is his greatest work." —David Schmidtz, University of Arizona