Difference and Repetition Book

In a certain sense the central idea of Difference and Repetition can be summed up reasonably quickly. Simply put, these two things, difference and repetition, have historically always been thought, starting from identity as the basis from which they can be determined. In other words, I have difference because I have something that is different from something which has been identically given, or, I have instances of repetition, because I am repeating things which we take to be identical in a certain sense. Deleuze contrary to this approach which has historically conditioned philosophy from Plato up until Hegel and the present day, will dedicate himself to the task of forging a concept of difference and of repetition in-themselves, that is to say, what would we be speaking of, when conceiving of difference via its own positivity, or of repetition via its own internal positivity, outside of their being coordinated according to the value of identity?
The response to this question has something to do with what Deleuze calls "the science of the sensible" or "transcendental empiricism". Broadly speaking, Deleuze is in dialogue with the empiricist thesis, principally sustained by Hume, that our experience is a set of sensations, which possesses the appearance of causality but whose fundamental causal coherence would simply be a habit of thought. Causality is a result of the habitual accumulation of these experiences which creates a commensurate habit of thought around these experiences. As such, Deleuze, as the name transcendental empiricism implies, intends on transcending the level of the conjunction of sensations, to go beyond this impasse in which Hume seems to place experience. To this end Deleuze divides his explicative model between what he calls the actual, that is, the side on which our own experiential life resides and the virtual, which Deleuze describes as the cause of the effect of the actual. While the virtual is transcendental in relation to the actual, it is immanent to itself across the differences which constitute it. The actual in broad terms is everything that we know of as the qualitative and quantitative world within which we live. The virtual is that condition which could bring about the genesis of the qualitative and quantitative contents of the actual world. In this way, Deleuze refers to the virtual as the being of the sensible, or the reason for the sensible, or finally the reason for qualitative diversity. The point however, is that the virtual is not, and never can be sensible; it is that basis of experience which cannot itself be experienced. In this sense the virtual must properly remain the unconscious of thought, that which can never enter into thought as a given content, but only as the condition of possibility for that which is given, which strips the given of its own self evidence.
Deleuze will be more specific however saying that intensity is the particular form of difference as the reason for the sensible. The virtual, more specifically then, is the structure through which the diverse distributions of intensive singularities and the differential relations which can pertain between them can sustain a form of coexistence in a spatium which will not be reducible to the spatiotemporally given. It becomes this spatiotemporally given in its actualization in the present world. That is, Deleuze will maintain that this intensive world of difference, or this world of implicated differences, these diverse distributions of differential relations, can virtually sustain coexistence amongst themselves within the virtual field. It is the fact that this difference as intensity is always asymmetrically or unequally distributed which leads to the processes of actualization which generate the formation of the actual world from the virtual coexistence of the differential elements. It is owing to this inequality of distribution that Deleuze names the fifth chapter of the book, "the asymmetrical synthesis of the sensible"; that is to say, the sensible contents of the world come to be via the asymmetrical distributions of intensity and the differences which result therein, which bring about actualization as sensible forms in the present, and habitually experienced world. Therefore the actual world for Deleuze is this constant explication of the implicated world of virtually coexistent differences. These differences are ideally synthesized in the virtual world according to the title of the fourth chapter.
The most important point for Deleuze however is that there is no form of resemblance which can be sustained between the virtual and the actual worlds. Within the virtual itself there are no processes which can be said to take place, which in any way conform to the notions of repetition of identical forms which we understand the actual world to be. Differences communicate in the virtual field by ressonance and forced movement which mean that there are no actually given identities which persist, but only singularities which find themselves always maintained within the patterns of interaction in the coexistence of the virtual. As such, difference in the virtual is the pure un-grounding of all forms, or the informal itself. For this reason the Deleuzian idea is radically opposed to the Platonic idea. The Platonic idea is the proposition of the notion of an ideal formality which can organize the appearance of particular cases in the actual world; Plato´s ubiquitous "chairiness" which would maintain the nomination of actual chairs in the sensible world. For Deleuze, to the contrary, the ideal condition is the absence of formality, or informality in the field of pure difference as the condition of possibility for formality in the actual world. There are things which actually possess form because the cause of the virtual coexistence of intensive differnces constantly produces the actualizations which produce all the forms of understanding which exist in the world of representation as conceived of via identity.
It is this then which determines repetition as the true potential of difference. Given that there is nothing which persists in the virtual as purely identical, the singularities are repeating each other throughout the differential system of communication, that is, the system repeats itself continuously, in the eternal return of it self differentitation, owing to the absence of identity in the virtual. Through repeating via difference rather than simly differentiating identities, it is this which Dleueze understands as giving his ontology a truely affirmative character. Being affirms itself by repeating itself throughout its differential system.