The essential difference between Nazism and Communism is not one of political philosophy or of political institutions. It does not lie in the range of political authority or in the way in which it is exercised, but in the purposes for which political power and political machinery are used. Nazism was the application of a totalitarian, single-party, police-State machine to the service of a racial Herrenvolk doctrine and an unlimited campaign of territorial aggression ready and willing to use war as an instrument of these aims. The only ideological element in it—the racial theory—is the concern not of philosophers but of ethnologists. In the USSR a very similar machine was applied for the institution and maintenance of new economic arrangements for ownership and control of factories and land, in the interests of the workers. The ideological element here concerns the economist, not the philosopher. The questions whether the arrangements are efficient, whether they really result in maximum benefits to the workers, what amount of control the individual worker in fact exercises—these are empirical questions in the field of economics or political organisation. Thus I hold that the political philosopher, as such, is no more required to hold a view either on the ideology of communism or on its practical application than he is required, as a philosopher, to hold a particular view on Free Trade or the merits of Co-operatives. Communism, like capitalism, is not a political philosophy.
(J. D. Mabbott, The State and the Citizen: An Introduction to Political Philosophy, 2d ed. [London: Hutchinson University Library, 1967 (1st ed. 1948)], 166-7 [italics in original])