This chapter seeks to address the question of ethics in Deleuze and Guattari's thought by way of an analysis of their engagement with Antonin Artaud. Deleuze and Guattari “use” Artaud in a variety of different ways: as an exemplary artist credited with discovering the “body without organs” (BwO); as both pioneer and model of a “thought without image”; and as a figure operating on the plane of immanence who refuses the transcendent judgment of God over the earth. But above all, perhaps, Deleuze and Guattari employ Artaud's writing in order to argue that “schizophrenia is not only a human fact but also a possibility for thought” (Deleuze 1994: 148). Intensive, schizophrenic experience has philosophical implications that must be brought to bear on how we conceive thought, language, and the encounter with difference, they argue. And it is here, in part, that ethical issues arise and indeed are raised by Deleuze and Guattari themselves. Is the academic use of Artaud opportunistic in the same way as was Lewis Carroll's use of nonsense, as Artaud himself once claimed? Do Deleuze and Guattari exploit Artaud's suffering by co-opting the concepts that arguably emerged from it – such as “cruelty” and the BwO – given that they did not undergo such suffering themselves? Is it unethical, as Artaud's friend Paule Thevenin once claimed, to brand Artaud “schizophrenic” in the first place? Or, finally and more broadly, to what extent does Deleuze and Guattari's affirmation of immanence and tempered advocacy of risk and experiment – where failure, including dangerous failure, is always an option – help us to practice an ethical but also sustainable relation to “madness”?