Like other concepts that have been legitimately used in order to diagnose the psychopathologies of totalitarianism, also the concept of "banality of evil" seems to be drifting in two different directions. On the one hand, this concept is often overused and has become somehow inflated. On the other hand, this discovery, disquieting and revolutionary as it was at the time when it was put forth by Hannah Arendt, has become more or less banal in its own way. Given this state of affairs, this paper takes up this issue and tries to give an answer to the following question: "What are we talking about when we talk of banality of evil?". In the same time, this paper tries to investigate on the relationship between the conceptual category of "banality of evil" and the related notion - that could be quite useful to a philosophical diagnosis of totalitarianism - of "voluntary servitude".
Keywords: Banality of evil, voluntary servitude, totalitarianism, Hannah Arendt, Étienne de La Boétie