This review revisits the role of race in Ernest Renan's thought by situating contemporary debates in a long perspective that extends back to his texts and their earliest interpreters. Renan is an ambivalent figure: from the 1850s onwards he used ‘race’ to denote firm differences between the ‘Aryan’ and ‘Semitic’ language groups in history; but after 1870, he repeatedly condemned biological racism in various venues and contexts. I show that the tension between these two sides of Renan's thought has continually resurfaced in criticism and historiography ever since the late nineteenth century. Renan's racial views have been subject to particularly close scrutiny following Léon Poliakov's and Edward Said's critiques in the 1970s, but the ensuing debate risks developing into an inconclusive tug-of-war between attack and apologia. I propose three fresh directions for research. First, historians should situate the evolution of Renan's ideas on race in closer biographical context; secondly, they must reconsider the cultural authority of his texts, which is often more asserted than proven; thirdly, they should pay greater attention to his reception outside Europe, particularly regarding his writing on Islam.