'John Rawls was the pre-eminent social theorist of the 20th century, but while he drew powerful critics from Robert Paul Wolff and Robert Nozick to Brian Barry, it is only now with Percy Lehning's new book that we have a definitive and comprehensive account of the theory of justice as it evolved over fifty years. Lehning has given students and scholars alike the indispensable introduction Rawls deserves.' Benjamin R. Barber, DEMOS and Author of Jihad vs. McWorld and Consumed