META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 336 META: RESEARCH IN HERMENEUTICS, PHENOMENOLOGY, AND PRACTICAL PHILOSOPHY VOL. V, NO. 2 / DECEMBER 2013: 336-354, ISSN 2067-3655, www.metajournal.org Mission Impossible? Thinking What Must be Thought in Heidegger and Deleuze Corijn van Mazijk University of Groningen Abstract In this paper, I discuss and compare the (im)possibility of thinking that which is most worth our thought in Deleuze's What Is Philosophy? (1994) and Heidegger's course lectures in What Is Called Thinking? (2004). Both authors criticize the history of philosophy in similar ways in order to reconsider what should be taken as the nature and task of philosophical thinking. For Deleuze, true thinking is the creation of concepts, but what is most worth our thought in fact cannot be thought. For Heidegger, Being calls on us think, and to think rightly is to be underway toward thinking itself, a grateful heeding of Being. In this paper I explore the very possibility to think that which is most worth our thought. I will argue that although for both authors proper thinking as such is possible, thinking what is most worth our thought seems remarkably both possible as impossible. Keywords: Heidegger, Deleuze, philosophical thinking, Being, presence, immanence 1. Introduction: Do You Think We Can Think? Do you think we can think? There seems already a paradox involved in the very phrasing of such a sentence. The line of reasoning that brings us to conceive of this apparent conflict is one that belongs to the heritage of Descartes; for how can one question or doubt that one can think without still being involved in thinking? Despite its contradictory appearance, it is this question that will be our central concern in what follows. The very nature of philosophical thinking itself, its true domain, limits and aims, is radically reconsidered and redefined in Heidegger's later thinking. In the interview in Der Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 337 Spiegel1, Heidegger considered What Is Called Thinking? as one of his least read books but nevertheless as one that addresses the most fundamental of all philosophical questions. On the French front, it was most notably Deleuze who drew attention to the very same question, via a reconsideration of what we have traditionally taken to be philosophical thinking. With regard to the question 'what is philosophy?' in Deleuze, we should be careful to discern, as with Heidegger, that which has been called philosophy and that which should be regarded as good philosophy. Difference and Repetition (1994) deals to the largest extent with the representational image of thought of traditional philosophy and expands on four 'iron collars' of representation and eight postulates of traditional philosophy which accord with this classic image of thinking. In What Is Philosophy?, by contrast, the 'image of thought' has become more or less synonymous to the notion of 'plane of immanence' and now concerns the true nature of all proper philosophical thinking. The four philosophical illusions, which tied us to representational thinking, in Difference and Repetition (1994), can be regarded – in a parallel fashion to Heidegger's metaphysics of presence – as Deleuze's starting point for arriving at a novel understanding of what it means to philosophize. For Deleuze, genuine thinking requires a reinstallment of an original difference and repetition, both of which cannot be thought in themselves as long as they remain subjected to the image of representation. General similarities between both authors can be said to stretch a long way. Heidegger and Deleuze are critical in comparable ways of propositional logic, dialectics and representationalism or metaphysics of presence. However, their conceptions of what constitutes true and good thinking can be argued to differ strongly. For Deleuze, problems are true, and good philosophy is knowledge through the inventing and thinking of concepts, which first requires the installing of an immanent plane. Philosophy, and philosophy alone, has an often misunderstood vocation for the creation of such true concepts, the truth of which can only be assessed relative to the respective plane. In What Is Called Thinking? (2004), Heidegger focuses more than before on language as that from which Being calls us META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 338 into thinking. Language is not the sum of all words and neither is it something like a tool we use; it is rather something originary that speaks itself through us. Language is taken to play a highly determinative role in the different ways in which Being calls on us to think. By considering language as an originary speaking it allows Heidegger to dig into specific words of which we have forgotten what they once spoke. Consequently, we can move through language – especially the German2 – like the 'billowing waters of an ocean' and retrieve a particular call to think, one which is perhaps more hidden from us now than ever before. For nowadays, everyone can speak with our language; we all have opinions, knowledge of facts, have questions and answers and we can all more or less reason logically. But does this mean that we can all think? To the contrary: precisely this modern way of thinking constitutes our forgetfulness of thought itself, thus preventing us from thinking, and in a way, that is what is most worth our thought today: the fact that we do not yet think. But our question remains: can we think at all? 2. Heidegger and the Call for Thinking For Heidegger in What Is Called Thinking?, the primary way to move toward a new understanding of thinking is by turning back towards our past. To consider the title question requires already that we distinguish several sub-questions. Firstly, we need to ask what the words thinking and thought signify, and secondly, what meaning we have usually given to them throughout our philosophical tradition. Thirdly, we may ask how we can think rightly, a question considered almost unanswerable, and lastly and most importantly, what it is that calls on us to think. For Heidegger, the fourth question has a certain priority over the others. Perhaps this primacy comes from the fact that it concerns the very nature and origin of thought itself, namely that from which it originally comes to us. The difficulty, however, is to find a more or less unbiased point of departure from which we can start our contemplations. With respect to this, a great deal of Heidegger's fascination goes to the pre-socratic philosophers, the thoughts of which he takes as Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 339 being yet unspoiled by the western philosophical tradition. It is here, then, that we may look for clues that bring a more original understanding of what it means to think closer into view. For Heidegger, one way to start such investigations is to take language for what it is. Precisely the 'floundering in commonness' with regard to our contemporary use of language makes Heidegger refer to it as a 'high and dangerous game' in which we ourselves are the stakes (Heidegger 2004, 119). It is the peculiar nature of language – which speaks through us rather than being a humanly controlled tool – which allows for a sort of retrieval of forgotten meanings. By means of a kind of philosophical etymology, Heidegger aims to retrieve what the word 'thinking' originally spoke before it got its permanent logical stamp through which we are still destined to consider it today. We will see that, if we are thus enabled to near a thinking about thinking in the fourth way, this would prove already to be a true thinking that is underway. The old English 'thencan', to think, in its relation to 'thancian', to thank, constitutes one of the windows opened by Heidegger through which we may peek into a more original understanding of what is called thinking. The German word for memory, Gedächtnis, also stems from thanc, and it still carries a connotation to thinking and similarly a clear relation to thanking (danken) in it. These relations have been forgotten today but were essential to our pre-logical understanding of thinking. According to Heidegger, memory, in its original sense, is not just a thinking or recalling of past events as we are used to taking it. Moreover, it is a thinking and at the same time a thanking of past, future and now, a meditative state of heeding that which is gathered and compressed in the living present. Memory, in this respect, is essentially a keeping safe. This keeping is, for Heidegger, not a human capacity; it is rather something that happens. Memory is a keeping which we as humans inhabit. As Heidegger emphasizes: 'Keeping alone [...] gives what is to-be-thought, [...], it frees it as a gift' (Heidegger 2004, 151). Consequently, the word thinking does not merely denote a thinking in its ordinary sense of reason and logic; it is said to have a close affinity to thanking and to memory as well. These META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 340 activities taken together constitute an original thinking that is a keeping safe and gratefully heeding of a gift. This stands in need of some further clarification. For one: what is kept in such a thankful keeping safe? For Heidegger, it is the presence itself, Being, which is heeded and most worth our thought not as the presence of things but as a play of concealment and unconcealment. It is from the presence of that which is present that there speaks an essential duality of Being and beings, of a presence and what is given as present. This duality is already elaborated on in much earlier works by Heidegger such as Vom Wesen des Grundes (1928), where it is referred to as the 'ontological difference' standing at the heart of the transcendence of Dasein. This duality or difference continues to play a crucial role in Heidegger's late thinking. An essential difference with this earlier work, however, is that in What Is Called Thinking? (2004) the human being does not execute this transcendence; it only keeps it. The difference between presence and that which is present – between Being and beings is at the very essence of thinking; it is that which first allows for thought and also that which calls us into it. Heidegger's discussions on how exactly this presence comes into view phenomenologically speaking and how we are to understand this are in my opinion somewhat unsatisfactory. I think that Husserl (1997) does offer satisfying analyses of similar intentional processes in discussing the origin of the constitution of the categorial objectivity (Husserl 1997, 217-313). For some reason, this connection is not made very often in secondary literature. Although Husserl's writings are highly complicated in their own ways, I believe that a short excursion to one of them will prove fruitful. I will try to briefly interpret Husserl's analyses in Experience and Judgment (1997) in the light of Heidegger's ontological difference in order to clarify the latter. For this, I will focus on the 'empty judgment' and the 'judgment of existentiality' which play important roles in Husserl's investigations. The empty judgment is a judgment which is not intuitively actualized in external perception at the moment of judging, something which is possible through the sedimentation of such originally intended judgments which are then retentionally retained Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 341 while losing their connection to the originary, actual fulfillment in perception. In other words, the empty judgment allows for a peculiar temporal distance within consciousness through which the judgment is seperated from the immediate perceptual givenness of the about-which of the judgment. The empty judgment can again find its original fulfillment, making the intention and the actual givenness match again, and if the ego actively runs over this passive process of matching, the judgment-content gets apprehended in a fundamentally different way then before. Husserl call this process 'substantivation', by which he means that a judgment such as 'P is s and q' which originally required multiple rays of attention (from P to s, then to q and back) can now be grasped in a single ray, namely as something like 'the fact that, S is p and q'. For Husserl, this is an intellectual achievement and therefore he calls this new, single object namely this single 'fact that' an 'objectivity of the understanding' or a 'categorial objectivity'.3 This process of constituting categorial objectivities here described in extreme simplicity is one in which consciousness apprehends an object which is not itself receptively given; it constitutes an ideal object. Furthermore, it is this process in which there is necessarily instituted a peculiar difference which is needed for the experience of truth and the judgment of existentiality (being). For Husserl, truth is the active experience of a peculiar synthesis of coincidence or fulfillment (Bernet 2003): the match described earlier between an anticipatory intention (of an empty judgment) and its actual fulfillment in experience. Hence, the experience of truth requires this difference, and because of this difference there is a possibility of doubt intrinsic to all judgments of truth or existentiality. For there will always be the need again and again to reassertain that the intended sense really corresponds to the actual experience, due to the fact that empty judgments have lost their connection to the original evidence. The important point for us to consider is that it is precisely here at the active synthesis of fulfillment lying at the heart of truth and the categorial object that we find the institution of a unique difference in consciousness between the intended sense and the identical object corresponding to this in experience. In the case META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 342 of a successful synthesis, we predicate the 'being' of the sense to the actually given object in perception. Here, consciousness thus transcends the objects immediately given and institutes an intellectual difference between the being of an object and the being it is. Now let us return to our question as to what is kept in the thankful keeping safe which Heidegger has called thinking. We already noted that this kind of thinking has its connections to memory, which in turn should be viewed as a keeping safe not only of something that has already past, but of everything which has gathered itself before us in the living present. We also noted that what we keep safe is the presence of the presented, the Being of beings, and that we as human beings only inhabit this keeping. Such a keeping is a heeding of Being; it allows Being to stand open. Consequently, we should note that thinking and Being, in this respect, really are two sides of the very same coin. For Being means presence and thinking keeps this presence of the presented and thereby frees it as a gift. As such, this duality or difference of beings in Being is also that which is most worth our thought, namely by heedfully keeping safe that which is gathered before us at any time: beings in Being (Heidegger 1961, 156). It is thus this duality itself which as a gift is most worthy of heedful keeping; it is what gives us 'food for thought'. By taking a halt, paying heed and keeping close to heart that which lies gathered before us at any time, we may allow the presence to be freed as a gift. What is thus most thought-provoking is the memory as a keeping, something by which we first allow the call to think to become manifest. This is how we are called into thinking. It is interesting to note that Heidegger's ideas stand in close affinity to Husserl's analyses. For Husserl, the judgment of existentiality, of predicating being, is an activity of the spontaneous understanding in which this being is produced. In other words, the ideal object which consciousness apprehends is nothing but the activity of synthesis itself (Husserl 1997, 207); here too, the being is the thinking. Clearly, what we thus think by way of heedfully thanking is not a that in the sense we are today used to conceptualize thinking. To think is not to consider a problem Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 343 and to attempt to find answers to it. There are no answers to be attained in genuine thought; one does not reach a point at which one has grasped that which is most worth thinking. Rather, it is precisely our common disposition to use thinking in this ontic sense which is worth our thought now; the fact that we expect of thinking that it would yield such results. Hence, that we are today not yet thinking and are perhaps at the greatest distance ever from it, is most worth our thought. It is this last phrase, 'that we do not yet think', which allows us to distinguish a two-folded structure at the roots of what calls us into thinking. Firstly, that we are not yet thinking means that we are called for thinking now because less than ever do we think in the right manner. This means that it is worth to think because we do not think. In a second sense, we are always called to think, for that which calls on us is the fact of Being of which we always already must have an understanding. Ultimately, what gives food for thought in this latter sense is thinking itself. What is worth thinking is the fact that things are and that we think them: precisely that we think is worth thinking. In other words, the thinking that comes from Being is itself what is worth to be thought; thinking is what is worth thinking. Although Grey says in the introduction to the translation of What is Called Thinking (2004) that Heidegger is 'persuaded that man is naturally inclined to thinking' (Heidegger 2004, xv), this phrasing is perhaps misleading. An inclination or affinity between thinking and Being makes it sound as if Heidegger needs such an affinity as a subjective presupposition. But the togetherness of thinking and Being is not presupposed; they are, to Heidegger, essentially one. Surely, it is not so that when we speak of Being we immediately intend to say thinking. But the meaning of thinking Heidegger is after is ultimately so tied to Being that both are inseparable. If we now compare our two senses of thinking just distinguished, what is worth thinking is precisely and simultaneously that we think and that we do not think. This does not constitute a satisfactory answer to our question yet: can we think what is most worth our thought at all? It is already admitted by Heidegger that the involvement with thought is rare, meant for a small number of people only. META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 344 On top of that, whether we are capable to think at all depends on whether we can let ourselves become involved in the call (Heidegger 2004, 126). But hereby not much is said, since thinking in fact is the being involved in the very question of thinking. To think is to be involved with it and as such to be on the way toward it. For Heidegger, then, true thinking is never to 'think the thought', that is, it is never to attain the thoughtful by thinking; rather it is only in movement toward it, and this being toward is precisely and already to think. The situation might remain vague unless we supply thinking with multiple meanings. In one sense, one never can think what is worth thinking, as if it concerned a thematic holding in grasp of the thoughtful, a that. But in quite another way, one can properly think what is worth our thought, namely by being underway toward thinking, a grateful heeding of Being. In this latter sense, it is not at all the difficulty of thinking which stands in our way, but rather its simplicity: to think is simply to let lie before you, and take to the heart, beings in Being. So how are we to understand the very possibility to think that which is most worth our thought? There seem to be several sides to this that concern us. What should strike us above all is the self-sufficiency of our reading of Heidegger. Given the close 'affinity' between, or better, the essential unity, of thought and Being, we can say that the fact that we think is itself worth thinking. Consequently, thinking and that which is to be thought come together in an apparently formal tautology. In thought, nothing in fact gives itself but itself. This tautology is quite clearly phrased by Heidegger: 'the keeping itself is the most thought-provoking thing, [which] itself is its mode of giving' (Heidegger 2004, 151 italics added). There is no essential difference between what is kept and what is given, between the thinking and that which is thought. In this sense, there seems to be a remarkable emptiness in thought, and neither is any-thing to be gained by its practice. Is the mere listening to the call, itself an empty giving, itself thinking? Does thinking become the mere attempt at an empty reflection on what is given to us? If the nature of thinking is indeed a formal apprehension, could it allow for more to be given than mere intentionality itself?4 It should be clear, at any rate, that Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 345 thought for Heidegger cannot be said to move forward in whatever way; it is rather circular. In line with this, Heidegger responds that in following the call from Being, we are admittedly never freed from what is asked of us; we can only respond to it by remaining underway (Heidegger 1961, 12). Can these apparent difficulties which seem to make thinking collapse into itself harm Heidegger's true intentions? I think that it could at least be argued that the structure of thinking here considered, much like Heidegger's understanding of truth as concealment and unconcealment, is so broad and allencompassing that it is threatened by unclarity5 and even by a vicious circularity. Similarly, it risks losing all bonds with the meaning we commonly ascribe to thinking. On the other hand, one might argue that we risk mistaking Heidegger's aims by reducing them to the logical structures of the argument. If we follow Samuel IJsseling's (2007) reading, we reach a different understanding, one in which thinking means that the grateful human being thinks and rethinks what is given to him, is thankful for this, and thereby participates in and completes the event of Being (IJsseling and Sevenant 2007, 41-43). Ultimately, according to this reading, to think is simply to be thankful; to gratefully rethink what has gathered itself before us. It is Being which deserves our gratitude and which we are called upon to keep safe. 3. Deleuze and the Plane of Immanence Although Deleuze's writing style is a world apart from Heidegger's, to interpret the first in its relation to the latter seems almost inevitable. Deleuze's attacks on representationalism do not take the Heideggerean form of a metaphysics of presence; neither do they make use of Being, the ontological difference or Heidegger's truth notion. Whereas much of Heidegger's terminology can be grasped and understood by practicing phenomenology, much of Deleuze's vocabulary may make a metaphorical impression upon the reader. Nevertheless, his approach is perhaps more systematic than that of the later Heidegger. For Deleuze, four 'iron collars' guide traditional representational thinking and eight META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 346 postulates are said to constitute the dogmatic image of thought of which representation forms a part.6 It is said that we have been alienated from what it really means to think by the traditional image of thought, in its turn guided by the Same and the Similar, which resulted in a subordination of the true powers of an imageless thought: difference and repetition. For Deleuze, good thinking is a two-sided constructivist's task; the creation of concepts and the institution of a plane of immanence. Although both are strongly related and intertwined, they are also strictly separate. According to Deleuze, the history of philosophy consists in a certain way of the institution of new immanent planes. In traditional philosophy, perhaps with the exception of Spinoza,7 immanence got tied up to various forms of transcendence. An example of this would be Husserl's absolute consciousness and immanent essences thereof, a model which maintains a relation of immanence to the subjective transcendent correlate of the ego. When the immanent plane is derived from or located in beings, one risks binding the autonomous immanent field to transcendent objects. There are striking similarities between Deleuze's account of this relation between transcendence and immanence and Heidegger's metaphysics of presence or ontotheology (Heidegger 2009). In both cases, there is an absolutization of something to a permanent presence whereby sameness is prioritized over difference. For Deleuze, each good philosopher of the past has instituted its own plane and many of these were made dependent on transcendence. In fact, Deleuze argues that it is impossible to think and create immanence that is not dependent on transcendence. The plane is like a 'section of chaos', a chaos which is even more original and fundamental than the plane. Ultimately, the choice will always be between a transcendence which can structure the chaos and the chaos itself Deleuze and Guattari 1994, 51). Here, then, both authors do have a disagreement; for whereas Deleuze sets metaphysics at the heart of good philosophy, Heidegger in his later life argues that philosophy as a whole has come to an end (Heidegger 1966). In every single case of instituting a particular immanent plane this allows for the creation of certain concepts that could Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 347 not have risen on other planes. Hence it can be said that there are multiple immanent planes. On the other hand, however, Deleuze seems to opt for a distinction between a multiplicity of immanent planes throughout time and 'the plane of immanence [which] is always single, being itself pure variation' (Deleuze and Guattari 1994, 39). At any rate, planes 'change' throughout time in whatever sense of the word; the image of thought of Plato is not the same as that of Descartes. That we ought to distinguish between the plane of immanence and concepts respectively becomes clear when the plane is characterized as the framework of thought itself, which means that it itself cannot be a concept (Deleuze and Guattari 1994, 34). In order to understand whether we can think that which is most worth to be thought according to Deleuze, we will distinguish between two different uses of the term plane of immanence – even though Deleuze does not explicitly separate them. On the one hand, when we talk retrospectively of the various planes of past philosophers, we are conceptualizing these different frameworks of thinking and thereby we consider their multiplicity. As we have seen, we can speak of such planes as being ''tied to transcendence''. On the other hand, we can also speak of the plane absolutely, that which is always the unthinkable framework of thought which we should conceive of as being independent from any transcendental determination. The plane is itself infinite, unthinkable and formal; a 'One-All' principle (Deleuze and Guattari 1994, 35, 39). It may appear as if the plane of immanence would be nothing but a formal abstraction. For Deleuze, however, the answer seems to be no: immanence is not an abstraction from transcendent experience but rather something original. It is not, as in Husserl, a flux related to a transcendent subject; it is rather a neutral, asubjective field, presenting only events and allowing for concepts and worlds to be created. Although the plane of immanence is pre-philosophical, it has to be 'instituted' by the philosopher. Thinking, for Deleuze, requires a plane to start from. We have already seen that philosophy is dependent on the institution of a plane, for it can only become philosophy by giving structure to chaos. Philosophy, in this respect, should acquire consistency without META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 348 losing difference and chaos out of sight (Deleuze and Guattari 1994, 42). At the birth of any plane, however, stands not just chaos, but also something which the author often refers to as 'stupidity' [bêtise] (Deleuze and Guattari 1994, 35, 39). To ground something, as Deleuze says, is to 'determine the indeterminate'. Determination does not just happen, but rises out of an empty ground, a faceless existence which is called a groundlessness. This groundlessness is something peculiarly intrinsic to thought, even though it often goes unrecognized.8 Stupidity, in this respect, is a specifically human trait, intrinsic to thinking and to any instituted plane. It is the greatest weakness of thought and simultaneously its highest power. How do we understand stupidity as the highest principle of thought while at the same time being the groundlessness of it? Czech phenomenologist Patočka discusses the relations between meaning, significance and meaninglessness which may help us grasp the essence of Deleuze's paradoxical phrasing. According to Patočka, the Fregean distinction between meaning and significance supports a classic metaphysical dichotomy, as they are understood to make reference possible to autonomous, objective qualities. If reality is understood as bearing such objective significances, whether inside or outside 'reality', then the meaningfulness of objects is ultimately guaranteed by these objective meanings. Consequently, a full loss of meaning is never truly uncovered, as the meaningfulness of reality is inherently given according to the particular rules which stand for determining significance. The history of philosophical metaphysics is for Patočka, as for Heidegger, bound to treating meaning as having objective value, which safeguards the meaningfulness of the world. However, meaninglessness as an experience is never completely alien to any philosopher, whether he reflects on it or not. Thinking, as it first rises in the Greek polis with Socrates (Patočka 1996, 62-63), is grounded in the experience of a 'shakenness of meaning' and all thinking is a way of dealing with and often an attempt to overcome the intrinsic possibility of a complete loss of meaning. The philosophical tradition is thus regarded by Patočka as ways of dealing with meaninglessness, which is characterized by Patočka as 'care for the soul'.9 Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 349 Patočka's loyalty to Heidegger is more evident than Deleuze's; it is only through our experience of meaninglessness – compare anxiety (Heidegger 2012, 225-228), boredom (Heidegger 1929, 5-6) or Abgrund,10 that we achieve an explicit relation to Being, by which genuine thought is first evoked. Care for the soul, in this respect, is the philosophical result of the unconcealment of Being which runs in a parallel fashion to Heidegger's metaphysics of presence and in a different way to Deleuze's representationalism. Understood from the viewpoint of Patočka's meaninglessness, we can see firstly how stupidity can be the greatest weakness of thought. Thought rises from the experience of a nullification of meaning or ground, and has to take this as its starting point for all attempts to determine that which has already given itself as inherently indeterminable. As Deleuze says: 'No image of thought can be limited to a selection of calm determinations, and all of them encounter something that is abominable in principle' (Deleuze and Guattari 1994, 54). Consequently, it is clear that with regard to stupidity as weakness there can be said to be hardly any distance from Heidegger or Patočka. That stupidity is also thought's highest power, is to say that it is prerequisite to thinking; it is what comes before it. Thought is thus grounded groundlessly: stupidity is its weakness as its groundlessness; it is its strength as its ground. Deleuze immediately follows up his discussion of stupidity with a quote from Heidegger: 'what gives us most cause for thought is that we do not yet think' (Deleuze 1994, 275). We should, however, be careful to take this sentence here in its Heideggerean fashion. What this quote in fact says in this context is that stupidity as groundless ground for thinking is the ultimate cause for thought. 'That we do not yet think', this means here: thinking rises from an abyss of non-thinking. Before thought, we thought not. This is contrary to Heidegger, who as we have seen also saves the more literal sense of the sentence; that we, twentieth century-born human beings, have the task set to reconsider what it really means to think. To come back to my central concern again: the plane of immanence, as Deleuze himself calls it, is what must be thought but in fact cannot be thought (Deleuze and Guattari META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 350 1994, 59). It is the base of all possible planes, the pure and unthinkable immanence in every thinking. How again to understand these awkward phrasings? Husserl makes a distinction between inconceivability and unimaginability which may help us understand this. According to Husserl in Ideas I, formal or ideal concepts, which allow for mathematical precision or exact determination, are such that one cannot in fact 'see' them (Husserl 1983, 166). That is to say, their content is essentially different from the nature of things as experienced in simple, perceptual intuition, in that the latter allow for intuitive fulfillment in external perception whereas the former do not. Consequently, it is perfectly possible to conceive of, say, a color without extension, but one cannot imagine it, that is, intuitively fulfill such an intention in imaginative intuition (Soffer 1990). We could say that the plane of immanence in Deleuze's philosophy is idealized and non-intuitable. Certainly the plane of immanence is conceivable, but it cannot be fulfilled in intuition. This does not imply that Deleuze thinks it would be unreal. We can now understand why Deleuze calls it the unthinkable within thought, stating that it is the most intrinsic to it and at the same time the most extrinsic. It is never to be within the reach of thought, even though it is always inherent to it and most deserves our attention. Regardless of this, there still lies a single most important task for philosophers: to show that the plane is there, even though it is never to be thought. The philosopher should try to think that which most deserves its attention, thus showing the unthought within thought (Deleuze and Guattari 1994, 59-60). 4. Conclusion: What Must be Thought, What Cannot be Thought The interpretations I have given of Heidegger's as well as Deleuze's reconsiderations of thinking show the complex structure of both expositions. Both Heidegger and Deleuze naturally hold that thinking is possible, but neither wants to commit to a form of correspondence and hence their characterizations of thinking are bound to become difficult and unfamiliar. Heidegger's break with tradition seems the most Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 351 radical; thinking does not learn or attain any-thing; it only keeps. Thinking is a keeping and heeding of the event of Being. By heeding, thinking helps to bring the event of Being to completion. The togetherness of Being and thinking in Heidegger is so strong that it appears an essential unity. However, the price for Heidegger's radical break is quite high. What Tugendhat (1967) says about Heidegger's extension of our traditional understanding of truth so as to make it so wide that it risks losing all of its traditional meaning, might equally apply to the notion of thinking here discussed. With respect to what is most worth our thought in Heidegger, I have argued for a twofolded structure. Firstly, that our generation does not yet think and has the greatest difficulty to do it constitutes one side of what gives food for thought now. However, what at all times is worth our thought is the call for thinking itself, regardless of how it is manifest to us. We are called into thinking and to think about this is already to listen to it and thereby to pay it heed. Thought in this sense is not after knowledge which it can or cannot attain; it merely keeps safe beings in Being. We have seen that this exposition of thinking is threatened by circularity. Regardless of this, we may conclude that to think in this most important sense is an essential possibility for every human being rather than an impossibility. Thinking is a call from Being, and whoever is related in whatever way to Being – whoever is Dasein – has the essential possibility of proper thinking. With respect to What is Philosophy? (1994), I have shown that for Deleuze thinking primarily means to create and invent concepts and to institute a plane. Good thinking does justice to the original forces forgotten by the traditional image of thought, difference and repetition, which form the abyss around which thought is bound to circle. Clearly, thinking is an essential possibility for Deleuze as a creative process. What is most worth our attention is the plane of immanence, the unthought within thought which by definition cannot be thought. This unthought is not a senseless abstraction; it is rather intrinsic to the structure of thinking. I have already pointed out important agreements between both thinkers with regard to the classic picture of META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 352 thought, characterized by means of metaphysics of presence, representationalism, propositional logic and dialectics. It is only on the basis of these commonalities that both set off into different directions with regard to redefining the meaning of thinking. One important similarity we may now add to this list pertains to that which is most worth our thought in both philosophies. For Heidegger as for Deleuze, what is most worth our thought is essentially unthinkable; hence it is not that which is most worth our thought. In the final account, for Deleuze as for Heidegger, the philosopher's task is not to think the impossible: rather it is to participate, to create, to accomplish, to keep and to heed. Thinking does not set out to let something out there enter it and to subsequently gain knowledge about that thing. Consequently, it is ultimately neither an intrinsic impossibility nor a tautology which we ought itself to think and to let enter our minds. No: the impossibility must not and cannot be attained directly; we should rather say that it should be circled around. By regarding thinking as an activity, we can now think how we can think what is most worth our thought even though to think it is impossible. For Deleuze, the most important task for any philosopher is the activity of showing that which is most worth our thought even though it cannot be thought. For Heidegger, what is most worth our thought is the activity of heedfully keeping that which lies before us. For both authors, then, despite all difficulties, that which is most worth our thought can indeed be thought in this sense: that we can actively participate in the problem of thinking. NOTES 1 The interview bears the title 'Only a God Can Save Us' (Heidegger 1966). 2 Heidegger conceived the Geman language to be the most suitable for doing philosophy due to its close affinity to the Greek language (Heidegger 1966, 62). 3 For the sake of simplicity I have here skipped many steps in this process of objectification, such as the constitution of the 'state of affairs' and the role of the 'two-membered predicative synthesis' – not to mention the passive syntheses also operative at the same time. For the core part here discussed see Husserl (1997, 237-239). Corijn van Mazijk / Mission Impossible? Thinking What Must be Thought 353 4 Derrida uses this phrasing in his introduction to Husserl's Origin of Geometry (Derrida 1962, 139). 5 Ernst Tugendhat argues this in the introduction to his dissertation (Tugendhat 1967, 4-5). 6 I will not expand on the postulates of the image of thought here. For the briefest summary see Deleuze (1994, 167-168). 7 Deleuze is known to refer to Spinoza as the 'prince of philosophers' (Deleuze and Guattari 1994, 60). 8 Among the eight postulates of the classic image of thought Deleuze posits the reduction of the trinity of stupidity, malevolence and madness to the single figure of external error. Error, in this respect, is only the failure of good sense within a framework of presupposed common sense, rather than being recognized as a necessary structure of thought (Deleuze and Guattari 1994, 150). 9 Care for the soul is one of the main topic in many of Patočka's works (Patočka 1996, 1998). 10 For a brief introduction to Heidegger's idea of Abgrund see Backman (2005, 175-184). REFERENCES Backman, J. 2005. The Absent Foundation: Heidegger on the Rationality of Being. Philosophy Today 49 (Issue Supplement): 175-184. Bernet, R. 2003. Desiring to Know through Intuition. Husserl Studies 19: 153-166. Deleuze, Giles. 1994. Difference and Repetition. Translated by Paul Patton. New York: Colombia University Press. Deleuze, Giles, Felix Guattari. 1994. What Is Philosophy?. New York, Chichester, West Sussex: Colombia University Press. Derrida, J. 1989. Edmund Husserl's Origin of Geometry: An Introduction by Jacques Derrida. Lincoln and London: University of Nebraska Press. Heidegger, Martin. 1929. What is Metaphysics?. Translated by Miles Groth. Unpublished. http://www2.sunysuffolk.edu/ fellenm/Handouts_files/PHL295/Heidegger.pdf, last visited 1218-2012 Heidegger, Martin. 1966. Nur noch ein Gott kann uns retten. Der Spiegel 30 (Mai, 1976): 193-219. [Heidegger, Martin. 1981. "Only a God Can Save Us". Translated by W. Richardson, in The Man and the Thinker, edited by T. Sheehan, pp. 45-67]. META: Research in Hermeneutics, Phenomenology, and Practical Philosophy – V (2) / 2013 354 Heidegger, Martin. 1961. Was Heisst Denken. Zweite, unveränderte Auflage. Tübingen: Max Niemeyer Verlag. Heidegger, Martin. 2004. What Is Called Thinking?. New York: Harper Perennial. Heidegger, Martin. 2009. Zijn en Tijd [original title: Sein und Zeit]. Vert. Mark Wildschut. Nijmegen: Uitgeverij Sun. Heidegger, Martin. 2012. Being and Time. Translated by J. Macquarrie and E. Robinson. Oxford: Blackwell Publishing. Husserl, Edmund. 1983. Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy. Translated by F. Kersten. The Hague, Boston and Lancaster: Martinus Nijhoff Publishers. Husserl, Edmund. 1997. Experience and Judgment: Investigations in a Genealogy of Logic. Evanston: Northwestern University Press. IJsseling, S., A. V. Sevenant. 2007. Wat Zou de Wereld Zijn Zonder Filosofie?. Zoetermeer: Klement/Pelckmans. Patočka, Jan. 1996: Heretical Essays in the Philosophy of History. Edited by James Dodd. 5th-6th essay, pp. 53-77, 95137. Chicago: Open Court. Patočka, Jan. 1998: Body, Community, Language, World. Chicago and La Salle: Open Court. Soffer, G. 1990. Phenomenology and Scientific Realism: Husserl's Critique of Galileo. The Review of Metaphysics 44(1): 67-94. Tugendhat, E. 1967. Der Wahrheitsbegriff bei Husserl und Heidegger. Berlin: Walter de Gruyter. Corijn van Mazijk is PhD Student at the University of Groningen, former Erasmus Exchange Student at the University of Leuven, Higher Institute of Philosophy. Research interests: History of Philosophy, Continental Philosophy, Phenomenology, Husserl. Address: Corijn van Mazijk University of Groningen Faculty of Philosophy Oude Boteringestraat 52 9712 GL Groningen, The Netherlands Phone: + 31.638252848 Email: c.m.a.van.mazijk@rug.nl, corijnvanmazijk@hotmail.com