 Markets are analyzed in a variety of disciplines, including sociology, history, and, most notably, economics. In philosophy, the interest in questions relating to markets has seen ebbs and flows. Starting roughly in the 18th century, one finds debates about a society in which markets are a social sphere of their own, and have an impact on society as a whole. This article presents the most important strands of the philosophical debate about markets. It offers some distinctions between the concept of markets and related concepts, as well as a brief outline of historical positions vis-à-vis markets. The main focus is on presenting the most common arguments for and against markets, and on analyzing the ways in which markets are related to other social institutions. In the concluding section questions about markets are connected to two related themes, methodological questions in economics and the topics of business ethics and corporate social responsibility.