Editing Gilles Deleuze (section)

=== Metaphysics<!--'Transcendental empiricism' and 'Transcendental Empiricism' redirect here--> ===
Deleuze's main philosophical project in the works he wrote prior to his collaborations with Guattari can be summarized as an inversion of the traditional [[metaphysics|metaphysical]] relationship between [[Identity (philosophy)|identity]] and [[Difference (poststructuralism)|difference]]. Traditionally, difference is seen as derivative from identity: e.g., to say that "X is different from Y" assumes some X and Y with at least relatively stable identities (as in Plato's forms). On the contrary, Deleuze claims that all identities are effects of difference. Identities are neither logically nor metaphysically prior to difference, Deleuze argues, "given that there exist differences of nature between things of the same genus."<ref>"Bergson's Conception of Difference", in ''Desert Islands'', p. 33.</ref> That is, not only are no two things ever the same, the categories used to identify individuals in the first place derive from differences. Apparent identities such as "X" are composed of endless series of differences, where "X" = "the difference between x and x<math>^\prime</math>", and "x<math>^\prime</math>" = "the difference between...", and so forth. Difference, in other words, goes all the way down. To confront reality honestly, Deleuze argues, beings must be grasped exactly as they are, and concepts of identity (forms, categories, resemblances, unities of apperception, predicates, etc.) fail to attain what he calls "difference in itself." "If philosophy has a positive and direct relation to things, it is only insofar as philosophy claims to grasp the thing itself, according to what it is, in its difference from everything it is not, in other words, in its ''internal difference''."<ref>''Desert Islands'', p. 32.</ref>

Like Kant, Deleuze considers traditional notions of space and time as unifying forms imposed by the [[subject (philosophy)|subject]]. He, therefore, concludes that pure difference is non-spatiotemporal; it is an idea, what Deleuze calls "[[Virtuality (philosophy)|the virtual]]". (The coinage refers to Proust's definition of what is constant in both the past and the present: "real without being actual, ideal without being abstract.")<ref>Proust, ''Le Temps Retrouvé'', ch. III.</ref> While Deleuze's virtual ideas superficially resemble [[Plato]]'s forms and Kant's ideas of pure reason, they are not originals or models, nor do they transcend possible experience; instead they are the conditions of actual experience, the internal difference in itself. "The concept they [the conditions] form is identical to its object."<ref>''Desert Islands'', p. 36.</ref> A Deleuzean idea or concept of difference is therefore not a wraith-like abstraction of an experienced thing, it is a real system of differential relations that creates actual spaces, times, and sensations.<ref>See "The Method of Dramatization" in ''Desert Islands'', and "Actual and Virtual" in ''Dialogues II''.</ref>

Thus, Deleuze at times refers to his philosophy as a '''transcendental empiricism'''<!--boldface per WP:R#PLA--> ({{lang|fr|empirisme transcendantal}}), alluding to Kant.<ref>Gilles Deleuze, ''[[Difference and Repetition]]'', Continuum, 2004[1968], pp. 56 and 143.</ref><ref>[[Adrian Parr]] (ed.), ''The Deleuze Dictionary (Revised Edition)'', Edinburgh University Press, 2010, p. 289: "Unlike Kant, Deleuze does not conceive of [...] unthought conditions as abstract or necessary philosophical entities, but as contingent tendencies beyond the reach of empirical consciousness."</ref> In Kant's [[transcendental idealism]], experience only makes sense when organized by intuitions (namely, space and time) and concepts (such as causality). Assuming the content of these intuitions and concepts to be qualities of the world as it exists independently of human perceptual access, according to Kant, spawns seductive but senseless metaphysical beliefs (for example, extending the concept of causality beyond possible experience results in unverifiable speculation about a first cause). Deleuze inverts the Kantian arrangement: experience exceeds human concepts by presenting novelty, and this raw experience of difference actualizes an idea, unfettered by prior categories, forcing the invention of new ways of thinking (see ''[[#Epistemology|Epistemology]]'').

Simultaneously, Deleuze claims that [[univocity of being|being is univocal]], i.e., that all of its senses are affirmed in one voice. Deleuze borrows the doctrine of ''[[ontological]] [[univocity]]'' from the medieval philosopher [[Duns Scotus|John Duns Scotus]]. In medieval disputes over the nature of God, many eminent theologians and philosophers (such as [[Thomas Aquinas]]) held that when one says that "God is good", God's goodness is only analogous to human goodness. Scotus argued to the contrary that when one says that "God is good", the goodness in question is exactly the same sort of goodness that is meant when one says "Jane is good". That is, God only differs from humans in degree, and properties such as [[good and evil|goodness]], [[Power (philosophy)|power]], [[reason]], and so forth are univocally applied, regardless of whether one is talking about God, a person, or a flea.

Deleuze adapts the doctrine of univocity to claim that being is, univocally, difference. "With univocity, however, it is not the differences which are and must be: it is being which is Difference, in the sense that it is said of difference. Moreover, it is not we who are univocal in a Being which is not; it is we and our individuality which remains equivocal in and for a univocal Being."<ref>''[[Difference and Repetition]]'', p. 39.</ref> Here Deleuze at once echoes and inverts Spinoza, who maintained that everything that exists is a modification of the one [[substance theory|substance]], [[God]] or [[Nature]]. For Deleuze, there is no one substance, only an always-differentiating [[process philosophy|process]], an [[origami]] cosmos, always folding, unfolding, refolding. Deleuze summarizes this ontology in the paradoxical formula "[[pluralism (philosophy)|pluralism]] = [[monism]]".<ref>''A Thousand Plateaus'', p. 20.</ref>

''[[Difference and Repetition]]'' (1968) is Deleuze's most sustained and systematic attempt to work out the details of such a metaphysics, but his other works develop similar ideas. In ''Nietzsche and Philosophy'' (1962), for example, reality is a play of forces; in ''[[Anti-Oedipus]]'' (1972), a "[[body without organs]]"; in ''[[What is Philosophy? (Deleuze and Guattari)|What is Philosophy?]]'' (1991), a "[[plane of immanence]]" or "chaosmos".