In the chapter of Gilles Deleuze’s The Fold: Leibniz and The Baroque where Whitehead makes a surprising and crucial appearance, Deleuze chooses to introduce the English mathematician and philosopher as the successor, or “diadoche,” of what he describes as a somewhat secret school. The reason for the secrecy of this school is itself something of a mystery. Even when Deleuze alludes to the question “What is an Event?” as a thread weaving its members together, it cannot be a coincidence that the term he uses to characterize these connections is that of an “echo.” For its secrecy speaks not of a desire from its members to remain unknown, isolated, hermetically closed upon themselves, but rather of the fact that the school itself remains somewhat secret even to those who have partaken and continue to partake in it. When has it been instituted as such? Who has ever succeeded in precisely identifying its members, in delineating its borders, listing its tenets, or endowing it with any authority of its own? What is it a school of? How can one join in?