This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book traces Aurel Kolnai’s investigation of National Socialism and Bolshevism up to The War Against the West in the context of the international debates on Fascism, Bolshevism and totalitarianism of the 1920s and 1930s. It demonstrates that Kolnai considered National Socialism the greater threat to Western democracies, without systematically comparing National Socialism to other totalitarian ideologies and movements. The book discusses Kolnai’s thesis on the irreconcilability of National Socialism and Christianity, while fundamentally questioning Kolnai’s view that National Socialism is a genuine anti-Christian and pagan movement. It discusses Kolnai’s definition of anti-Semitism in the light of his main thesis that anti-Semitism is an attitude directed against normatively defined Western culture. The book discusses Kolnai’s thought in the context of twenty-first century conservatism, particularly the thinking of Karl Popper and Michael Oakeshott.