The traditional understanding of desire assumes an exclusive distinction between "production" and "acquisition." This line of thought—which has dominated Western philosophy throughout its history and stretches from Plato to Freud and Lacan—understands desire through the concept of acquisition, insofar as desire seeks to acquire something that it lacks. This dominant conception, Deleuze and Guattari argue, is a form of philosophical idealism. Alternative conceptions, which treat desire as a positive, productive force, have received far less attention; the ideas of the small number of philosophers who have developed them, however, are of crucial importance to Deleuze and Guattari's project: principally Nietzsche's will to power and Spinoza's conatus. Deleuze and Guattari argue that desire is a positive process of production that produces reality. On the basis of three "passive syntheses" (partly modelled on Kant's syntheses of apperception from his "Critique of Pure Reason"), desire engineers "partial objects, flows, and bodies" in the service of the autopoiesis of the unconscious. In this model, desire does not "lack" its object; instead, desire "is a machine, and the object of desire is another machine connected to it." On this basis, Deleuze and Guattari develop their notion of desiring-production. Since desire produces reality, social production, with its forces and relations, is "purely and simply desiring-production itself under determinate conditions."