John Rawls' "A Theory of Justice" has been influential in philosophy, political theory, welfare economics and jurisprudence. This book is thought to be the first full-length study of Rawls' work. It provides a concise account of Rawls' central ideas, situates them within contemporary debates, and submits them to critical scrutiny. Kukathas and Petit discuss, among other things, the utilitarian orthodoxy and its problems; the emergence of majoritarian and other social choice alternatives; the contractarian synthesis and its policy implications; the notion of reflective equilibrium; and the various critiques of the contractarian view.
26 years later, this is still a decent summary/overview of Rawls' philosophy. At 150 pages it's by far the shortest intro to Rawls I know, shorter than any of the more recent and more detailed accounts.
Written in an accessable way (maybe a little too accessable in some parts) and gives a decent overview over the most important critics of Rawls. Helped me learning for my exams.