What is Philosophy ?, published in 1991, was Gilles Deleuze’s last book. This may appear as a matter of contingency since there was a rumour, some time before his death, that Deleuze was preparing a book on Marx. However, contingency in this case is not interesting, because Deleuze knew he was approaching the threshold.

Whoever has seen his Abécédaire, or has read A Thousand Plateau’s “Apparatus of Capture”, knows that the theme of the threshold is very specific with Deleuze, as it is connected with his past experience with alcohol. “There is a conceptual difference between the “limit” and the “threshold” (… ) What does an alcoholic call the last glass ? The alcoholic makes a subjective evaluation of how much he or she can tolerate. What can be tolerated is precisely the limit at which, as the alcoholic sees it, he or she will be able to start again (after a rest, a pause…). But beyond that limit there lies a threshold that would cause the alcoholic to change assemblage (…) It is of little importance that the alcoholic may be fooling him – or herself, or makes a very ambiguous use of the theme “I am going to stop”, the theme of the last one. What counts is the existence of a spontaneous marginal criterion and marginalist evaluation determining the value of the entire series of “glasses””. (TP, 438)

We may find, in What is Philosophy ?, a nearly clinical description of what it may mean to feel the approach of the limit when the demands of philosophical creation are concerned : “Weary thought, incapable of maintaining itself on the plane of immanence, can no longer bear the infinite speeds of the third kind that, in the manner of a vortex, measure the concept’s copresence to all its intensive components at once. It falls back on the relative speeds that concern only the succession of movement from one point to another, from one extensive component to an other, from an idea to another, and that measure simple associations without being able to reconstitute any concept.” (WPh ?, 214).

What I will characterize as Deleuze’s last message has nothing to do with the way he eventually crossed his last threshold ten years ago. There is no message there, as it was not the act of a philosopher, but the act of someone who knew that the threshold that really mattered for him had already been crossed, that he would never be able to start writing an other “last book”. All we can say is that he did not fool himself about it. Indeed his death as a philosopher was broadcasted about one year before his physical death, with the Abécédaire picture, filmed in 1988-1989 and broadcasted on Arte between November 1994 and spring 1995. The explicit condition for the making of film, as announced at its beginning by Deleuze himself, was that it would be broadcasted after his death only.
I remember repeating again and again, when I heard his way of departing, “it is not sad”. What is really sad, or pathetic, what Deleuze refused, is the fate of those who have crossed the threshold and do not know it : “those weary old ones who pursue slow-moving opinions and engage in stagnant discussions by speaking all alone, within their hollowed head, like a distant memory of their old concepts to which they remain attached so as not to fall back completely into the chaos.” (WPh?, 214)

If what counts is the existence of a marginalist evaluation determining the value of the entire series, as a positive problem of limit, not a catastrophic problem of threshold, Deleuze’s last message is indeed this book titled “What is philosophy ?”. Not a weary book at all, but an old age book, when the point has been reached “where one can finally say, ‘What is it I have been doing all my life ?’” (WPh?, 1). Before that point “there was too much desire to do philosophy to wonder what it was”. The answer to the question will not of course pass a judgement on the entire series of books and teaching, when Deleuze was doing philosophy and not wondering what he was doing. To determine the value of the series is not to judge, it is not to tell what was hidden behind each term of the series, and it is not to define where the series was leading, its aim or final truth. Determining the value is thus not coming back to the past, in order to elucidate it. Reaching the point where you can ask, “what is it I have done all my life ?” is reaching the point where “my life” becomes “a life”, with all the terms of the series coexisting and resonating together as they escape the times and circumstances that marked each of them.

However, it is not because Deleuze did reach such a point that I feel authorized to associate his last book with a message. The starting point for this association was in fact my own experience when reading What is philosophy ? Till then I had never felt like commenting or teaching a Deleuze’s book. I used his concepts only when they had become tools for my own hand, when I would not explain them but be able to take them on. I felt that this was what those books asked. Even when teaching, Deleuze would never answer a question, enter into a discussion or explain himself. He would listen and smile. Maybe what you would feel as an answer would come later, but in an indirect way and as an event. You would never know what kind of part, if any, your question or suggestion had played in what you received as an answer. Here, for the first time, I felt as if I was addressed, as if something that matters had to be conveyed to me - not to me as a person but as somebody who would have to go on living in this world for some time. Writing or teaching in direct reference to What is philosophy ? is not, for me at least, a matter of explaining or of using, but of receiving and continuing. Deleuze loved the Nietzschean image of the arrow thrown as far as possible, without knowing who will pick it up, who will become a relayer. His last book addresses relayers, or more precisely puts them in the position of feeling addressed as eventual relayers.

However, the book has also produced a completely different reaction. For many readers it was a great disappointment, even a betrayal. They had associated Deleuze and Guattari with the affirmation of productive connexions, the creation of deterritorializing processes escaping fixed identities, transgressing boundaries and static classifications, destroying the power of exclusive disjunction, that is the either/or alternatives. They anticipated a joyful celebration of experimentations that subvert the very identity of philosophy, that undermine the very persona of the philosopher. Instead, they got exemplifications from so-called “great philosophers”, Plato, Descartes, even Kant. As if, when the question “what is philosophy ?” was directly at stake, Deleuze had chosen to side with his great forerunners and forget his deterritorization allies. As if philosophy itself, as the work of Dead White Males, was suddenly innocent of any connection with power issues, gender issues, the disqualification of trouble makers of all kinds, cultural imperialism, and so on.

This feeling of a catastrophic regression in the professional territory of “great philosophers” has been all the more vivid because this was a Deleuze and Guattari book. We do not know when Guattari came to be associated with the project. Those who have seen the Abécédaire know that at the time of its filming, Deleuze was preparing this last book. Some of the main themes of the answer to the question “what is Philosophy ?” were already spelled out, for instance the contrasted characterization of philosophy, science and art. At that time he did not associate Félix Guattari with this project however.

I will thus begin with this aspect of Deleuze last message, not interpreting but emphasizing the importance of this last association, of this decision that this book - a book Deleuze knew quite well his colleagues philosophers would read and quote - would be co-signed together with Felix Guattari. I take it as a first aspect of the message, the most obvious one, addressed to all those philosophers who nicely separate Deleuze’s own books and the DeleuzeandGuattari ones, which they prefer to ignore. “You will not part us, you will be obliged to type down this name, “Felix Guattari”, that you would so much prefer to ignore, each time you will refer to What is Philosophy ?.
I am not claiming at all that this was the only reason. It may well be that when we read that the question had to be asked “between friends”, or as “a challenge when confronting the enemy”, both Deleuze and Guattari knew very precisely other necessary reasons why Guattari would co-author this rather obviously Deleuzian book. I can just testify for my own joy when I discovered that the answer to this question - an answer that “had to determine its moment, its occasion and circumstances, its landscapes and personae, its conditions and unknowns” (WPh?, 2) - would include the affirmation of an effective togetherness , which Gilles Deleuze explicitly challenged anybody to deny or denigrate.

This message, however, is not only addressed to Gilles Deleuze’s colleagues, as it could then be reduced to social psychology, or to an operation in the landscape of professional evaluations and judgements. Deleuze allying himself with Guattari when answering the question “what is it I have been doing all my life ? ” is also a double affirmation. First, that the answer is not a matter of reflection, of I, Deleuze, reflecting on my own activity. It is a matter of creation. Second, that the part Guattari played in Deleuze’s life as a philosopher was a vital one, something which belongs to the very question “what is philosophy ?”

We read in What is philosophy ? that “the non philosophical is perhaps closer to the heart of philosophy than philosophy itself” (WPh ?, 41). The negative, “non philosophical”, does not designate any lack. It designates heterogeneity, positive divergence and contingent reason. It designates the need for an encounter that does not explain but produces - what Deleuze and Guattari called an heterogenesis, something new created in between two terms who keep their heterogeneity. The very birth of philosophy is referred to encounter and contingent reason in What is philosophy ? : “What we deny is that there is any internal necessity to philosophy, whether in itself or in the Greeks (and the idea of a Greek miracle would only be an other aspect of this pseudonecessity). Nevertheless philosophy was something Greek – although brought by immigrants. The birth of philosophy required an encounter between the Greek milieu and the plane of immanence of thought (…) The encounter between friend and thought was needed.” (WPh?, 93)

The encounter is never between two persons. More precisely it is not between two persons as they would be able to communicate and agree. The encounter between Deleuze and Guattari was the encounter between two lines that contingently discovered that they needed each other, not to cumulate knowledge or exchange experience, but to cross a threshold - a distinct one for each probably, but one both needed in order to escape suffocation.

If we refer to the common title of Deleuze and Guattari’s two main books, Capitalism and Schizophrenia, it could be said that Deleuze vitally needed the encounter with Guattari because his problem as a philosopher was an exercise of thought that would positively affirm that we no longer live in the Greek milieu, an exercise of thought that would escape guilt, negativity or nostalgia for this lost Paradise. In between Deleuze and Guattari this exercise of thought stopped being a theme for thought, with reference to Spinoza and Nietzsche, and turned into an effective experimentation, and a schizoid one indeed, since the very figure of one author, or of two authors coming into an agreement, has been disarticulated into what they later characterized as an ongoing process of capture, robbery, hijacking and negotiation without mutual intersubjective understanding.
A famous theme of Deleuze and Guattari’s writing is the theme of the symbiotic relation between wasp and the orchid, an “unnatural nuptials”, they wrote, outside the logic of lineage, a double becoming, each becoming an organ for the other. That thought would grow by symbiosis and asymmetric captures may have been already the case in the Greek city, but it belongs to the era of Capitalism, destroying all codes, all settled territories, all natural or civic laws, to unleash what it cannot master : not the revelation of what was hidden but, in this case, an experimental actualization of what it means to cross the threshold when thinking is no longer the natural activity of a thinker.

It is not that Deleuze would have been defined, before this encounter, by an academic tradition. His Logic of Sense, book is haunted by Malcolm Lowry and Francis Scott Fitzgerald, and it is even dominated, through Antonin Artaud, by the schizophrenic onslaught on perverse surface thought, when the body is depth only, carrying away and engulfing all sense. However, in Logic of Sense, Deleuze wrote that Artaud and Lewis Carroll, the master of the logic of sense and the art of surface, do not meet. Only the commentator, he wrote, can have them meeting by a thought operation, freely changing dimensions, that is contrasting with impunity the mastery of the logic of sense and the monstrous depth that destroys all sense. And this, Deleuze adds, is the commentator’s - or the philosopher’s - weakness, the sign that he inhabits none of these dimensions, that he is thinking by proxy (LS, 114).

In Logic of Sense, it is already the very question “what is philosophy ?” that is at stake. Deleuze denounces what he describes as Leibniz’s “shameful declaration”, that philosophy should create concepts but at the condition of not attacking the established ways of thinking (LS, 141). But condemning Leibniz may not be sufficient to escape the “shame to be a philosopher”. The question insists again with the famous sentence, when Deleuze affirms that he would not give one page of Antonin Artaud in exchange for the whole work of Lewis Carroll, (LS, 114) You cannot read Logic of Sense without feeling the haunting question : how to be a philosopher after Antonin Artaud ? How not to think by proxy ?, how not to remain on the surface ? This was a question Deleuze left unanswered even when he invoked an humoristic art of the surfaces, that of the Stoic thinkers of the event. The last page of Logic of Sense asks to imagine someone who would be one third Stoic, one third Zen, one third Carroll, and who would masturbate with one hand while, with the other, writing on the sand the magic words of the pure event. But this is still imagining, and the feeling of guilt is not exorcized.

One way another, when Deleuze did encounter Guattari, the problem did change. The philosopher is no longer thinking by proxy but together with what Americans call an activist, the untiring actor, thinker, cartographer and connecter of collective processes of deterritorialisation, of creations of collective assemblages of enunciation, that are less against capitalism than produced in an affirmative experimental process of escape from both the plane of capital and the plane of subjection. Thinking with Guattari excluded the subjective, depressive complaint - how to be a philosopher in front of solitary heroes, whose ordeal, beyond the limits of sense, may inspire shame to the one who remains on the bank, commenting. Indeed the point was no longer, could no longer be, how to rejoin Artaud, just as Artaud himself, for whom writing was writing “for” the illiterate, “for” the agonizing rat, or the slaughtered calf, did not mean he identified himself with an illiterate, a rat or a calf. The point is becoming and a becoming is always double. “The agony of a rat and the slaughter of a calf remains present in thought not through pity but as the zone of exchange between man and animal in which something of one passes into the other. This is the constitutive relationship of philosophy with nonphilosophy”. (WPh?, 109)
The event of the Deleuze and Guattari encounter is associated with their famous Anti-Oedipus. What is less often underlined is that, as all encounters, it produced its own questions, its own learning process following the first shock, the publication of the Anti-Oedipus and its instant celebrity. How to avoid any confusion between “passing into” and exploding boundaries ? How to convey that the zone of exchange has to be produced, that the transition from separated, stratified, organized spaces, to a smooth nomadic space is not a matter of destruction, but of creation ? Those are questions that will resonate again in What is Philosophy ?, as I will try and show. Correlatively, it can be said that what I called Deleuze’s last message is indeed a Deleuze and Guattari message, something that cannot be dissociated from what they learned together.

It is important to emphasize first that Anti-Oedipus was not a triumphalist book. It was written after May 68, when everything that had got opened was closing down, when the masterword, “it was but a dream, let us go back to reality” was already encoding the event as a past memory. Anti-Oedipus gave voice to the trust, an ontological, enacted trust, that this so-called dream we were asked to forget was reality, and that nothing would stop it.
As such, yet, Anti Oedipus was denounced as responsible the catastrophic trajectories of many young people using drugs and self-mutilation as if they had wished to demonstrate the validity of Deleuze and Guattari’s trust and reach Antonin Artaud’s body without organs that Anti-Oedipus had made famous. In A Thousand Plateaus, Artaud and the body without organs are still there, but the important question is now : “How do you make yourself a body without organs ?”, how do you fabricate an escape line from the “Judgment of God” that steals your organs and submits them to the law of an organism ? Deleuze and Guattari do not recant, or admit responsibility. Why would they, since what happened was indeed not a result of their book, but, rather, a consequence of the suffocating closure that crushed all escape lines after 68 ? But they point instead to a technical problem they had not anticipated in Anti Oedipus, the confusion between experimentation and precipitation. “Why such a dreary parade of sucked-dry, catatonicized, vitrified, sewn-up bodies, when the Body without organs is also full of gaiety, ecstasy, and dance ? (…) Emptied bodies instead of full ones. What happened ? Were you not cautious enough ? Not wisdom, caution.” (TP, 150).

The distinction between wisdom and caution is a crucial one. It means that to the question “What happened ?”, to the accusation that Anti-Oedipus made many victims, the answer will not be “sorry, we feel responsible for the many who were defeated in this battle, now we are wiser and sound the retreat from the battle ground”. Deleuze and Guattari do not address those who would anticipate regrets and excuses anyway. They do not discuss with them. They address only those to which the need must be conveyed for caution, for affirmative, step by step, productive experimentation, against the temptation of precipitation. “How can we convey how easy it is and the extent to which we do it every day ? And how necessary caution is, the art of dosages, since overdose is a danger. You don’t do it with a sledgehammer, you use a very fine file. (…) You do not reach the Body without organs by wildly destratifying. That is why we encountered the paradox of those emptied and dreary bodies : they had emptied themselves of their organs instead of looking for the point at which they could patiently and momentarily dismantle the organization of the organs we call the organism.” (TP, 160).

The affirmation that the making of a Body without organs is indeed dangerous, that it needs caution, may be connected with many other themes in A Thousand Plateaus, and everywhere it means “do not proceed in the name” of anything, even of Artaud. Especially not Artaud ! Make connections, fabricate, be meticulous, beware of any precipitation, do not confuse consolidation, the gain of consistency, with stratification. Consolidation is creation.

“Staying stratified – organized, signified, subjected – is not the worst that can happen; the worst that can happen is if you throw the strata into demented or suicidal collapse, which brings them back down on us, heavier than ever. This is how it should be done : Lodge yourself on a stratum, experiment with the possibilities it offers, find an advantageous place on it, find potential lines of deterritorialization, possible lines of flight, experience them, produce flow conjunctions here and there…” (TP, 161) Even Antonin Artaud did proceed with caution. When writing, he was not a wild schizophrenic, he did weigh and measure every word, and wrote about the danger of false sensations and perceptions. Not only he experienced such sensations and perceptions, but sometimes he did believe in them.

Those are very relevant advices, even in an academic job like teaching philosophy. Obviously it may happen that one deals only with what Deleuze and Guattari designated as the worst : “ the worst is the way the texts of (…) Artaud have ended up becoming monuments, inspiring a model to be copied (…) for the artificial stammering and innumerable tracings that claim to be their equal.” (TP, 378). But it also happens that you feel the proximity of what is named, in A Thousand Plateaus, a “black hole”, or the presence of what Deleuze and Guattari characterize as a central point “that moves across all of space and at every turn nourishes a certain distinctive opposition… when the entire opposition at the same time resonates in the central point.” (TP, 292). All you can say to a student is then “please, slow down; it is not that you are wrong, it is that you risk precipitating yourself into the point when everything begins telling the same story, when everything has become obvious”.

Those two same correlated themes, danger and caution, are quite present in What is philosophy ?. The exercise of philosophy, “the art of forming, inventing and fabricating concepts” (WPh?, 2), may be dangerous, is dangerous. But what comes first now is the relation between the illusions that threaten this exercise, and the concept of the plane of immanence, the plane that the creation of concepts presupposes, requires and institutes.
Illusions get listed as they make the history of philosophy as distinct from the becoming of philosophy. There is the illusion of transcendence, which surrounds any affirmation of immanence, as soon as immanence is made immanence to something; the illusion of universals, arising as soon as we think that the universal explains, whereas it is what must be explained, the triple illusions of contemplation, reflection and communication, and then the illusion of the eternal, when it is forgotten that concepts must be created, and the illusion of discursiveness, when propositions are confused with concepts (WPh?, 49-50). Philosophy is not what would avoid those illusions. Those illusions are rather the specific illusions that surround philosophy, that arise from its very exercise. The philosopher cannot avoid them, as he or she would avoid mistakes, and cannot deliberately oppose them, as such an opposition would become the central point, where the entire opposition against the illusion would resonate at the same time. Caution is the only advice because it is not the content of thought that is threatened by illusion, but the very regime of thought as it is affected by the plane of immanence.
It is thus the plane of immanence that illusions surround, as if by a thick fog. They arise when the thinker cannot bear any longer what this plane both causes and requires, as it affects thought : speeds of the third kind. Illusions arise as soon as the thinker tries to get back to a knowledge of the second kind, to ascertain a sound relation with communicable matters of fact or to answer questions that are no longer ingredients in the process of creation but act as stopping points : “What is it that I am doing ?”, “How to define and justify ?”, “How to explain ?”.

“To think is always to follow the witch’s flight” (WPh?, 41). The witch is an interesting figure if we remember that her broom had no motor, that it was flying because of forces that she was able to invoke and convoke, but not define as her own, as her property. If the witch is not cautious, if she thinks that what makes her fly belongs to her, if she ignores or forgets the required protection formulas, she will be swept away.

This may be related to the characterization of the plane of immanence as a section of chaos. A section of chaos is not chaos, as chaos undoes any consistency and engulfs those thinkers who have not learned that setting up the plane of immanence, consolidating a section of chaos, is not siding with chaos against what would repress it. Philosophical thought is able to invoke, convoke and even inhabit a section of chaos, but it must proceed by an immanent process of discovery. The crucial point that links the creation of concepts as they answer problems, and the plane of immanence, is that the problems appear in the very process of creation of concepts answering other problems. The plane of immanence manifests itself in the experience that each conceptual solution is a creation that cannot be separated from the production of new unknowns, as if you were exploring a moving landscape. As if you were dealing with something that destabilizes any appropriation, that resists any identification into a set of related propositions to be discussed and defended. The very reality of the plane of immanence is the sort of permanent “groping experimentation” it demands (WP?, 41).
There is a deep affinity between this pragmatic of creation and William James writing in Some Problems of Philosophy (p. 230) that “we can and we may, as it were, jump with both feet off the ground into or towards a world of which we trust the other parts to meet our jump”. This, Deleuze and Guattari would add, may include measures “that are not very respectable, rational, or reasonable”, as they belong “to the order of dreams, of pathological processes, esoteric experiences, drunkenness and excess” (WP? , 41) but those measures all imply the art of dosage. Indeed, whatever the measures, they are needed to sustain, not to produce, and what they sustain may be called belief or trust, in William James’ meaning of those terms. Belief, or trust, is what is needed to resist the lethal oscillation between fear and wilfulness, fear that if there is no rule, no standard, nothing will oppose subjective arbitrariness, and then wilful despotic affirmation exploding the fear and bringing it along. Any weakness leads to illusion. The philosopher must trust what James would call an immanent process of verification, the groping possibility to evaluate problems and solutions in the very process of their construction.

As for James, the immanent criterion for this evaluation is not validity. The plane of immanence, as it is both required and instituted by the creation of concepts, is not a transcendental condition, that would communicate with justification, when conditions are fulfilled. No condition can determine the satisfaction of “categories like Interesting, Remarkable, or Important” (WPh?, 82). Those categories require a pragmatic evaluation in terms of success or failure, and success or failure cannot be known, or, more precisely, cannot be tasted, in advance, before being constructed, only as we go along. “”When Nietzsche constructed the concept of ‘”bad conscience’ he could see in this what is most disgusting in the world and yet exclaim, ‘This is where man begins to be interesting !’” (WP, 83).

I recalled William James because he is the very example of the Anglo-American way of doing philosophy that is celebrated in What is Philosophy ? as knowing how to nomadize on the plane of immanence, treating it “as a movable and moving ground, a field of radical experience”, not to lay foundations like the Germans or to erect conceptual building like the French : « the English inhabit. For them a tent is all that is needed” (WPh?, 105) A matter of trust again. But I also recalled James because for Deleuze, following Jean Wahl, he is the most eloquent witness for the Anglo-American philosophy as it was assassinated. William James knew and fought those who would kill him – not physically, but as a philosopher -, he analysed their hate for trust, that they despised as credulity. As such, his voice is at the very heart of What is Philosophy ?

We arrive here, at last, to the very peculiarity of Deleuze’s last book that allows me to speak about a “message”. The concept of concept, together with the mode of existence of the immanence plane, were created in order to answer the question “what is philosophy ?”, but not as the answer to a general question. The “what is” question, the quest for the right definition, designates what Deleuze, as a philosopher, always fought, because it leads right to the illusions of contemplation, reflection and communication. If I dare to speak about Deleuze’s last message, it is because what is produced, as a definition of philosophy, is like an arrow, thrown with the trust that it can be picked up by others he will not know : maybe later, maybe quite elsewhere. It is thrown with the knowledge that philosophy has already been assassinated in many places and could well be eradicated everywhere. Just as the witches have been burnt, eliminated away, and by the same kind of people, the ones that think that thought is made for reasoning and brooms for cleaning the ground.

Paraphrasing Nietzsche in What is Philosophy ?, I would propose that “when Deleuze constructed the concept of the probable assassination of philosophy, he could see in it the most disgusting triumph of la bêtise – there is no word to translate “bêtise”, I will thus use the usual translation, “stupidity”, but I must recall there is no “stupor” in la bêtise, and that for Deleuze “la bêtise” is active, enterprising, malicious, enjoying its own destructiveness. And yet maybe he exclaimed “This is where the question of philosophy as such begins to be interesting !”.

The book opens with an evocation of old age, as the time “for speaking concretely” (WPh?, 1). What does it mean, to “speak concretely” ? Here we come to the accusation of betrayal that I already have noted. Speaking concretely would mean siding with the Dead White Males, the usual great philosophers like Plato, Descartes or Kant. When old age came, Deleuze would have announced that it was time to stop joking and playing with interlopers. The time would have come to speak concretely, that is to claim not only that philosophy is a creation of concepts, but that “the concept belongs to philosophy and only to philosophy.” (WPh?, 34)

However, to speak concretely also means that, when old age came, it was time for Deleuze to become a witness for what made him a philosopher. The problem is no longer an abstract one, “how to be a philosopher ?”, as it was in Logic of Sense. With Guattari, Deleuze has become able to affirm that philosophical creation has nothing to do with commenting by proxy. The concrete problem is that of the probable destruction of philosophy.

In the Abécédaire, Deleuze recalls his own first encounter with concepts, at secondary school, when he heard for the first time about Plato’s ideas. After this first philosophy lesson, his life was decided. In other words he had encountered Plato’s propositions not as objects of thought but as conveying what those propositions could not define, the efficacy of concepts that signals that, together with them, comes the experience of the plane of immanence as it affects thought. This personal memory is all the more interesting because he would later be described as a radical anti-Platonist philosopher. The point is not that Deleuze would finally admit a personal debt to Plato, as the one who initiated his becoming philosopher. The point is the lack of, and vital need for, what is called, in What is Philosophy ?, a pedagogy of concepts, as the only safeguard against absolute disaster (WPh?, 12).

If philosophy is threatened by an absolute disaster, it not as an innocent victim. To affirm that the concepts belong to philosophy, and to affirm a vital need for a pedagogy of concepts, imply that the killers would not be able to kill without an internal weakness, a lack of resistance. It is this lack of resistance that the book addresses. Philosophers have not been able do defend and honour what made them philosophers, hiding it away behind false representations that produced the vulnerability of philosophy. “Even Descartes had his dream” (WPh?, 41) but he presented himself as grounding valid reasoning on certain foundations. Socrates was presented by Plato as freely discussing with friends, but “Socrates constantly made all discussion impossible (…) He turned the friend into the friend of the single concept, and the concept into the pitiless monologue that eliminates the rival one by one.” (WPh?, 29).

Deleuze’s last message includes what could be a pedagogy of concepts, as it conveys what made him a philosopher, the encounter that decided that his thinking life would be philosophy. It is not a question of debt at all, rather a matter of relays. It may be what Deleuze, at the beginning of What is philosophy ? called a point of non style. Pedagogy is not faithful transmission. Plato, Descartes or Kant are not faithfully portrayed. But the impossibility or vanity of faithful transmission is not to be identifier with the freedom to grasp and steal. Stealing, or grabbing whatever you like, is not a problem as such. The problem would be to derive grabbing and stealing as a new general model, mobilizing against the dead conformity of transmission. This conformity is a ghost anyway. We certainly never know what we transmit because what is meant to be transmitted never explains its own transmission. This is what makes a relay interesting. Relay transmission implies both taking over and handing over. The take over is always a creation, but the act of handing over also requires a creation, the creation of an arrow, conveying and honouring what produced the one who hand over, and will produce others.

The feeling of betrayal this last book did cause may then be part of the problem. Maybe those who felt betrayed needed to believe that it was in order to escape the dreary stratification of thought that is named philosophy that Deleuze had become a nomad, and maybe they needed to believe that to become a nomad means freely grabbing in a smooth space without boundaries between musicians, scientists, movie makers, novelists or schizophrenics. But smooth, or nomad spaces, like bodies without organs, are to be made, linkage by linkage, step by step. The joy of productive connexions cannot be betrayed, it will proceed as it must, and needs no model, no master thinker. It does not need the togetherness of a mobilized group against en enemy, what it produces is rather a wild bunch, with diverging singular paths resonating with each other, each becoming more apt to resist because of the delocalized co-presence of others. It cannot be confused with the global law of the market plus a principle of freedom meaning that everyone can grab whatever the or she feels like.

Becoming the witness for a threatened practice is a task that tolerates no economy. It demands making explicit the specific vulnerability the enemy must be exploiting since he (or it) does not need to use violent, repressive means, just the gentle admonishing to behave and accept being bound by the rules of public argumentation and evaluation. Such a vulnerability must be produced against any mobilizing generality. The philosopher must speak concretely, that is, situate his or her practice among other threatened practices, each from the point of view of its own weakness and eventual capacity to resist. When calling for the seemingly modest task of a “pedagogy of the concept” as the only possibility to avoid absolute disaster, and not for a mobilization against a general enemy, Deleuze speaks concretely, speaks about his practice’s own specific “bad will”, what forces the practitioner to think and create, as opposed to good will, to being allowed to think by consensual evidence, even the consensual evidence that our time demands a general subversion of identities.

This leads me finally to the most intriguing aspect of Deleuze’s last message, the fact that his answer to the question “what is philosophy ?” implied also answering the question of what is science and what is art, furthermore adding to this double definition what sounds like a true prohibition. “Thou shall not mix” : scientists should not ask philosophical questions about their results, and philosophers should not intervene when scientists are at work, or are facing new troubling questions, even if it may seem obvious that the elucidation of philosophical presuppositions could play a role, and even if it seems quite desirable that scientists experiment with new philosophical possibilities. “Philosophy can speak of science only by allusion, and science can speak of philosophy only as of a cloud. If the two lines are inseparable it is in their respective sufficiency, and philosophical concepts act no more in the constitution of scientific functions than do functions in the constitutions of concepts. It is in their full maturity, and not in the process of their constitution that concepts and functions necessarily intersect, each being created only by their specific means.” (WPh?, 161)

Correlatively, both science and art receive what may appear very classical definitions. Science, as the creation of functions, looks like the Royal science, the producer of theorems and static categories that was typified against nomad sciences in A Thousand Plateaus. As for art, not only the term is not deconstructed or debunked, but Deleuze and Guattari are clearly speaking about “oeuvres d’art”, not about post-modern cultural production. “Composition, composition is the sole definition of art. Composition is aesthetic, and what is not composed is not a work of art” (WPh?, 191). Composition is not grabbing and freely patchworking, the problem of art is the creation of blocs of sensation, that is to say, compounds of percepts and affects, with the sole law, “that the compound must stand up on its own” (WPh?, 164). “Even if the material lasts for only a few seconds it will give sensation the power to exist and be preserved in itself in the eternity that coexists with this small duration. So long as the material lasts, the sensation enjoys an eternity in those very moments” (WPh?, 166).

From my own experience as a philosopher who begun learning how to be a philosopher working with a physicist, Ilya Prigogine, I can but agree with the prohibition. Prigogine struggled with what may indeed appear as a philosophical problem par excellence, the problem of time, the identification between complete physical description and an explicit equivalency between past and future. His lifetime work resulted in what he considered as an achievement of major importance, the creation of a well-defined relation between an irreducibly probabilistic time-asymmetrical mathematical representation and the class of those dynamic systems for which this representation is necessary. In order to follow what I would call Prigogine’s passionate experimentation with functions, philosophy’s specific means were of no relevance. My own participation in his work was a matter of putting it into historical perspective, of following how the paradoxes and blind generalizations implied in the so-called fundamental laws of nature, acquired their strange, quasi-metaphysical authority. But it was a complete surprise and even a shame to discover the many references in philosophical and cultural studies that were made to Prigogine and Stengers’ theory of irreversible time. The very association of our two names was displaying a complete misunderstanding of the demanding character of physical mathematics’ own specific means.

When I came to use philosophy’s specific means in order to situate the question of the order of nature, I could refer to Prigogine only by allusion, because the time had come for me to think with Alfred North Whitehead concepts, concepts that, from the start, take for granted the absurdity of the authority of the laws Prigogine spent his whole working life to disarm.

“Specific means” do not refer to an hegemonic authority but to each practice’s own specific way to diverge, that is the specific difference each practice is making between a failure and an achievement, and its specific evaluation of what it means for a solution to be Interesting, Remarkable, or Important. Already in Logic of Sense, Deleuze had linked divergent lines and communication. Communication is only through divergence, or else it is only redundancy and generalization. But the affirmation of divergence as something to be consolidated by each practice’s specific means refers to the learning curve that I described and that results in what Deleuze and Guattari call “constructivism’ in What is Philosophy ? What matters with a construction are the immanent constraints, how it holds together, the tests it has to survive and the false perceptions it has to avoid.