This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book is devoted to totalitarian philosophy, mainly as it appears in the work of fascist philosophers such as Gentile and Carl Schmitt. It considers whether the definition of totalitarianism as total control of the individual by the state is sufficient to distinguish it from ‘mere’ dictatorship or tyranny. In 1945, the year that saw the end of World War Two, totalitarianism was one of the main contenders for the title ‘spectre haunting Europe’. The term ‘totalitarianism’ soon acquired a wider currency, however, and especially in the work of critics whose attitude towards the ideas, the ambitions and, ultimately, the regimes of Mussolini and Hitler was far less enthusiastic. Totalitarianism raises questions for disciplines other than philosophy.