Rang was a Protestant pastor stationed near Poznań in modern-day Poland, then part of Prussia. The church, which he subsequently abandoned, had a mission to ‘Germanise’ the local population. Weber draws parallels between this apparently benign ambition and the subsequent murderous impulses of the third Reich, although a definitive portrait of her ancestor keeps eluding her. After his apostasy he became friends with several great early-twentieth-century thinkers, including Hugo von Hofmannsthal, Martin Buber and Walter Benjamin, with whom he hoped to create a movement devoted to world...