Derrida reacted to Foucault’s History of Madness by insisting that the very project of that work, namely to “make madness speak,” was as mad as it was necessary. Sharing the commitments which gave sense and force to the gesture of the book, Derrida was drawn to identify the difficulties Foucault’s project could not, on his analysis, avoid. An untenable reading of Descartes, Derrida argued, was the symptom of the conflict between project and accomplishment; unsustainable by other standards, it held up the book’s architecture and claims. Thirty years later, Derrida professed not to want to return to the quarrel, declaring that those interested should refer to the archive already constituted. Exploring what Custer takes to be a delayed reactivation of the exchange, she considers why Derrida’s posthumous publications – notably his seminar on the Death Penalty and The Animal that therefore I am – should be added to this archive. Some implicit arguments in these works sound eerily the same as those with which Derrida had taken issue in his debate with Foucault. Custer suggests that this does not mark the possibility of a reconciliation but does offer a productive place from which to revisit the problem for which “Descartes” came to stand as a symbol. Today, when the project of giving voice to those who have been silenced has become a cliché of political activism and reading practices, it is useful to reactivate Derrida’s warnings about the mad nature of Foucault’s project.