The main goal of this book is to examine the relation between agreement and majoritarian voting, as the twin bases of thinking legitimacy in the modern era and founding modern political philosophy. The author approaches the topic above all through the classical theorists of social contract, Thomas Hobbes and John Locke, as well its criticism in David Hume. On the other hand, the book looks at the relevance of this topic for contemporary normative political theory and theory of democracy. Some of the important issues contemporary theories face are precisely the way in which they determine the adequate procedure of political decision-making for a given community, as well as the best way of establishing such a procedure.