Atlantis has been adapted to countless ideologies and agendas over time, serving the needs of every sort of reader - "harmless hippies or Heinrich Himmler", in Mr Kershaw's memorable phrase . . . Mr Kershaw closes this chilling chapter [on 'the white-supremacist thread in the Atlantis story'] with a quote from Hannah Arendt suggesting the larger importance of his topic. "The ideal subject of totalitarian rule," Arendt wrote, is "people for whom the distinction between fact and fiction . . . and the distinction between true and false . . . no longer exist." The tortured moves that Mr. Kershaw documents, by which the Atlantis myth has been recast as fact and willfully misread, remind us of how vital such distinctions are for a society striving to stay free.