This paper critically reviews the 2025 Korean edition of Bettina Stangneth’s Eichmann Before Jerusalem. By successfully demonstrating through extensive undisclosed sources, including the ‘Sassen papers,’ that Eichmann was a subject of ‘evil thinking’ who orchestrated the genocide out of conviction, Stangneth refutes Hannah Arendt’s ‘banality of evil’ thesis based on ‘thoughtlessness’ and restores Eichmann as a historical figure. This article comparatively analyzes critiques of Stangneth’s interpretation and the criticisms Arendt faced at the time of her publication, shedding light on their respective historical, social, and academic contexts. The purpose of this critiques is not to determine the superiority of one interpretation over the other, but to evaluate how both perspectives can complementarily contribute to understanding the complexity of Holocaust perpetrators. To this end, it accesses the position of Stangneth’s research within the historiography of perpetrator studies (Täterforschung). While her study contributes to perpetrator research by restoring Eichmann as a historical figure, it shares with Arendt’s work the characteristic of an inherently ‘ahistorical approach’ by concentrating on individual-level analysis.