A delicate problem animates chapter 3 of Difference and Repetition.  Deleuze wants to defend a pure concept of difference, an account of difference in itself, yet our experience is representational through and through.  Everywhere we are creatures of habit that recognize beings and therefore do not encounter difference.  We subordinate the beings of our experience to the same, similar, and the identical, assimilate what we experience to what we have experienced.  Wesen ist gewesen.  What, then, authorizes Deleuze to claim that there is something like difference in itself?  Is it not the case, as Hegel and Kant perhaps suggested, that everything is always already mediated or subordinated to the logic of representation (identity in the concept, analogy in the judgment, opposition among predicates, and resemblance in perception)?

In chapter 3 of Difference and Repetition Deleuze will present what might be called a sort of “anti-phenomenology” that authorizes an appeal to difference in itself.  He will claim that there is an experience in which we do, in fact, encounter difference in itself.  Where so much of phenomenology– and I know I’m not here being fair –sets out to demonstrate how we recognize things or how we always encounter them within a horizon of meaning (again a system of recognition), Deleuze will look at the dark side of experience, pointing to those moments where the system of meaning and recognition fails.  Thought, Deleuze will argue, only occurs under the force of an encounter.

…there is only involuntary thought, aroused but constrained within thought, and all the more absolutely necessary for being born, illegitimately, of fortuitousness in the world.  Thought is primarily trespass and violence, the enemy, and nothing presupposes philosophy:  everything begins with misoophy.  Do not count upon thought to ensure the relative necessity of what it thinks.  Rather, count upon the contingency of an encounter with that which forces thought to raise up and educate the absolute necessity of an act of thought or a passion to think…

Something in the world forces us to think.  This something is an object not of recognition but of a fundamental encounter.  What is encountered may be Socrates, a temple or a demon.  It may be grasped in a range of affective tones:  wonder, love, hatred, suffering.  In which tone, its primary characteristic is that it can only be sensed.  (DR, 139)

Everything goes wrong from the outset if we assimilate thought to simple cognition.  This is Deleuze’s primary reproach against so much of the history of philosophy, and would no doubt be his criticism of cognitive science which takes itself to study thought:  they assimilate thought to simple recognition.  Yet for Deleuze, thought is essentially rare.  We cognize and recognize all the time as creatures of habit (the first synthesis of repetition in Chapter 2), but we do not yet think.  It is only as a shock to our system that we begin to think.  There can thus be no method of thought, nor a willing of thought, because in its initial phase, it is entirely passive.  We can only undergo the force of a fortuitous encounter that involuntarily instigates thought within us (and clearly this is often a very unpleasant thing).  In Lacanian terms, we could say that thought is the result of trauma, of the missed encounter, of that that evades the symbolic net we throw over the world to render it re-cognizable.

read on!