Few approaches in political science have generated so much controversy as rational choice theory. Some claim that the approach has made political science scientific. Its critics argue that it involves unrealistic assumptions about individual behaviour. While its tenets and benefits remain the subject of heated debate, rational choice theory is now established as a core approach in political science and one that is vital for contemporary students of the discipline to understand. With an impressive degree of clarity, the book introduces the philosophical foundations, the methodology and the key issues of rational choice theory. It shows how the approach has been constructively used to explain political phenomena and also reflects more broadly on how theories are developed and used in political science. Balanced and insightful, this important new text gives a nuanced and elegant evaluation of the potential and limits of rational choice theory.