This chapter considers elements of political science historical development, and presents the main topics and issues addressed by scholars and the different kind of methods they use to study conspiracy theories. It aims to synthesise the most relevant findings, which will lead us to attempt to give a definition of conspiracy theories that finds a consensus in the field of political science. Although its origins are widely recognised to lie in the philosophical debates on politics since the time of ancient Greece, political science as a structured discipline engaged in empirical research only began to emerge at the end of nineteenth century. Political science is considered the academic discipline that studies formal and informal, conscious and unconscious, visible and invisible relations of power, authority and domination amongst individual and/or collective actors of all kinds. Political science is then divided into several sub-disciplines such as history of ideas, political sociology, public policies, public institutions, government studies, comparative politics or international relations.