Conrad of Hirsaus Trees of Vices and Virtues: From De fructu carnis et spiritus
Conrad of Hirsaus Trees of Vices and Virtues. Conrad of Hirsau (c.1070 – c.1150) created the famous Trees of Vices and Virtues in De fructu carnis et spiritus, which he prepared before 1133 for illiterate lay brothers.