Few other economists have been read and cited as often as R.H. Coase has been, even though, as he admits, "most economists have a different way of looking at economic problems and do not share my conception of the nature of our subject." Coase's particular interest has been that part of economic theory that deals with firms, industries, and markets -- what is known as price theory or microeconomics. He has always urged his fellow economists to examine the foundations on which their theory exists, and this volume collects some of his classic articles probing those very foundations. "The Nature of the Firm" (1937) introduced the then-revolutionary concept of transaction costs into economic theory. "The Problem of Social Cost" (1960) further developed this concept, emphasizing the effect of the law on the working of the economic system. The remaining papers and new introductory essay clarify and extend Coarse's arguments and address his critics. Many economists today approach economics as technicians. Coase approaches it as a philosopher. He thinks and writes in a dep and contemplative way, and his work is rooted in a careful and deliberate scrutiny of real conditions and a thinking through of their consequences.