For Cassin, as a Republican jurist, being a Jew was not a matter at the centre of his life before the war of 1939. In this domain, war and the Shoah turned Cassin’s work and thinking in a new direction. To be sure, Cassin’s life as a Jew antedated his Jewish life as a public figure. We have traced the early contours of his family life, in which his parents’ relationship to Judaism was a source of conflict, possibly contributing to his parents’ divorce. When, before 1914, Cassin made it clear that he lived with a non-Jewish woman, Simone Yzombard, he was telling his family more than that he had started his adult life. He was saying that his choice of partner was made outside the faith, and, like his father before him, that his life and its contours would not be defined by it. He did not attend synagogue, and did not engage in Jewish community life; there is no record of any participation in active Jewish circles, and he was not a Zionist.

Cassin’s standpoint was shared by most Jewish Republicans at this time, including Marc Bloch. Bloch was a man of his generation – he was born in 1886 and Cassin in 1887. He was a soldier of the Great War too, and in his testament of 1943 he refused any ‘cowardly denial’ and continued: ‘Remote from any religious form as well as any so-called racial solidarity, I have felt, through my whole life, above all, simply a Frenchman.’