Isidore Isou has largely been forgotten or ignored by historians of culture. This is partly because he believed something that was absurd and impossible: he was a fanatic who held the fantastical belief that he was the Jewish Messiah sent to lead all humanity to redemption. His most tragic belief was that through the philosophy and practice of lettrisme he could find the secret of immortality. The aim of this article is however to reinstate Isou to his true position in the twentieth century by considering his practice as an avant-gardist. The article focuses on the parallels between lettriste word collages and the “cut-ups” of William Burroughs. Although Burroughs and Isou never met, there is striking similarity in the practice which reveals the cross-currents at work in 1950s Paris, where Isou and Burroughs lived and worked.