This paper shows that there is one and the same break in theartistic creative process of Robert Smithson and in the philosophical creative process of Gilles Deleuze and Félix Guattari. For Smithson it takes place between Site-Nonsite works (1966-9) and Earthworks (1970-3). For Deleuze and Guattari it happens in the transition from Difference and Repetition (1968) to AntiOedipus (1972). Smithson's break marks his abandoning of the institution in favour of an art of direct intervention, the Earthworks confronting one of the most pressing political concerns of his (and our) time, the destruction of the earth. Deleuze and Guattari's break happens as they take us from a conceptual mapping of structures to a material machinery of production that allows thought to engage with real political processes.