Neither ‘totalitarianism’ nor ‘fascism’ is a ‘clean’ scholarly concept. Both terms have, from the beginning of their usage, served a double function: as an ideological instrument of negative political categorization, often serving in common parlance as little more than ‘boo-words’; and as a heuristic scholarly device used in an attempt to order and classify political systems. It is as good as impossible to treat them as ‘neutral’ scholarly analytical tools, detached from political connotations. Scholarly debate about the use of the terms illustrates above all the closeness of the mesh of history, politics, and language.

—Ian Kershaw, The Nazi Dictatorship, (London: Bloomsbury, 2015), 38‑39.