Majority Decision

This chapter provides a brief history of voting and of collective decision-making, especially in the medieval Catholic Church and in the late medieval and early modern representative bodies. The focal questions are how and why people accepted the authority of any purely mechanical procedure—be it the simple majority-principle, a two-third rule, or something else. This is not just a historical problem. Rather, some important theoretical disputes on the nature of democracy are related to this issue. The development of democracy can been as a breakthrough of the legitimacy of purely mechanical procedures. I present the most elementary result of the social-choice theory: the so-called May’s Theorem. I review the discussions about the theorem and try to show how, contrary to some claims, it captures at least a part of the democratic idea of political equality. The “paradoxes” of the social choice emerge when we move away from the simplest case characterized by a single issue, only two options, and a direct choice.