This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book introduces the concept of ideology and its pervasiveness within financial economics. It shows that financial economics’ “methodology of positive economics” is a very rational-sounding process that is in fact much better at perpetuating a system of academic gamesmanship than it is at explaining just what it is that is going on in the real world of finance. The book deals with a more thorough description of the process of thought contagion by which financial economics theories are disseminated and perpetuated within the academic community. It addresses the absurdity of the exclusive use of mathematical models in financial economics and argues that instrumentalist methods were a consequence of academic “jousting”. The book considers the issues and suggests that sociological and anthropological theories of fashion might help to understand the investment behavior of individuals.