By his intellectual contributions in economics, epistemology, ethics, law, philosophy, politics, and psychology, Hayek has come closest to a unified theory of human action. The central theme is of a natural and spontaneous evolution: founded upon essentially competitive processes, the cultural selection of systems and rules brings order to human affairs. While this book is both concise and comprehensive, Hayek's economics cannot be discussed in isolation. So, the author attempts to present an economist's understanding of that which any economist ought to know; or, in Hayek's own terms, 'nobody can be a great economist who is only an economist'.