This paper examines how Gilles Deleuze critically transforms the theory of thought from representation to production, by way of finding thought’s genetic conditions, in his synthesis of time and ideal synthesis in Différence et répétition. I focus on Deleuze’s critique of subject, time, and identity, and on how he tries to establish a purely positive synthesis capable of producing the absolutely new. Lastly, I discuss Deleuze’s own image of thought that rises from his critique, as simulacrum.