The Nasirean Ethics is the best known ethical digest to be composed in medieval Persia, if not in all mediaeval Islam. It appeared initially in 633/1235 when Tūsī was already a celebrated scholar, scientist, politico-religious propagandist. The work has a special significance as being composed by an outstanding figure at a crucial time in the history he was himself helping to shape: some twenty years later Tūsī was to cross...