In his 1968 book Difference and Repetition, Gilles Deleuze famously stresses the violent, unnatural and shocking character of thought, counterposing his own anti-representational philosophy of difference to what he depicts as a dogmatic, humanist ‘image of thought’.
In his own words: ‘“Everybody” knows very well that in fact men think rarely, and more often under the impulse of a shock than in the excitement of a taste for thinking.’  In his commentary on Deleuze, François Zourabichvili has shown how this repudiation of the idea that thought is coterminous with human nature, that thinking is a natural and constant exercise of human beings’ ‘common sense’, plays a pivotal role in Deleuze’s association of thought with the notions of the ‘outside’ and the ‘event’. In Zourabichvili’s helpful summary: ‘thought affirms an absolute relation to exteriority, refuses the postulate of recognition, and affirms the outside in this world: heterogeneity, divergence. When philosophy renounces the activity of foundation, the outside abjures its transcendence and becomes immanent’.  Deleuze’s sundering of the lineage of rationalism (pitting Spinoza against Descartes) can accordingly be understood as a split in the understanding of what it is to think in general, and to think being in particular.
In order to examine this radical division of what goes by the abridged name of rationalism, and what Deleuze’s role is in the constitution of what some have seen as a kind of contemporary anti-Cartesian doxa in Continental philosophy and critical theory,  I will focus on the relatively subtle changes in Deleuze’s portrayal of Descartes as the purveyor of a ‘dogmatic image of thought’, and then move on to how Deleuze inflects and transforms the widespread condemnation of Descartes’s dualism.
The chapter on ‘the image of thought’ in Difference and Repetition clearly prefigures What is Philosophy? (written with Félix Guattari) in posing the problem of thought as the problem of beginning to philosophize without presuppositions, a problem with an incontestable Cartesian pedigree. But does philosophizing without presuppositions surreptitiously mobilize certain varieties of philosophical pre-understanding, or prephilosophical understanding? In particular, the chapter on ‘the image of thought’ anticipates the engagement with Descartes in What is Philosophy? when it adumbrates, in what might be regarded as an anti-modernist vein, the theme of beginning in philosophy. Given the power and pervasiveness of the figure of Descartes as the inceptor of ‘modern’ philosophy, and the broadly anti-Cartesian orientation of Deleuzean philosophy, it is particularly interesting to see this trope at work. Of course, the theme of presuppositions is also closely linked to that of immanence, which might also be envisaged as something like an abandonment of all presuppositions. But is this what Deleuze is aiming at? Is the forsaking of presuppositions not instead a gesture redolent of the Hegelian movement of the concept which, whilst acknowledged as precursor of the project outlined in What is Philosophy?, remains a definite rival for Deleuze? Is immanence marked by a certain relationship to presuppositions rather than an absence or repudiation of them? After all, for Deleuze the singularity of philosophy should not be confused with its legislative autonomy and/or transcendence.
One might wonder in this regard whether the later development of the idea of a plane of immanence, for instance in A Thousand Plateaus, is to be considered as an evacuation of presuppositions or on the contrary as a new use of presuppositions.
Deleuze distinguishes between objective and subjective presuppositions. In the case of Descartes, according to Deleuze, we witness a kind of trade-off between the two forms of presupposition: Descartes abandons ‘objective’ presuppositions, which would locate the concept of the Cogito within an objective taxonomy of other concepts – for instance, presupposing rationality and animality in the definition of man as a zoon logikon4 – for the sake of an intensification of subjective presuppositions. This, of course, is the philosophical sin for which Deleuze chastises Descartes: going ‘too fast’ into the arms of ‘opinion’, as he tries to escape the ‘objective’ clutches of Aristotelian scholasticism. What Descartes’s philosophy brings to the fore – and what still powerfully abides, as Deleuze notes, in Heidegger’s ‘pre-ontological understanding’ – are ‘subjective or implicit presuppositions contained in opinions rather than concepts: it is presumed that everyone knows, independently of concepts, what is meant by self, thinking, and being’.  The ‘subjective’ is here the site of a kind of cloaked anticipation, whereby the subject of opinion – the one who tacitly knows just what it is, or what it is like, to be a cogitating subject – underlies the seemingly purified subject engineered by the internal theatre of the Meditations: ‘The pure self of the “I think” thus appears to be a beginning only because it has referred all its presuppositions back to the empirical self.’ This critique of the epitome of a modern beginning in philosophy opens up the question of the compatibility between the theme of immanence, so dear to Deleuze, and that of radical commencement, together with the repercussions of such a notion of commencement on his conceptions of subjectivity and the event. What is clear is that for Deleuze’s philosophy beginning cannot simply take the guise of a punctual caesura, a cut, an interruption, a wiping of the slate. Indeed, we could see in Deleuze’s repudiation of a certain modern notion of commencement his distance from the Christological or messianic thread that underlies much of the subjective and historicopolitical temporality of modernity. In Difference and Repetition, Deleuze thus suggests the possibility that ‘there is no true beginning in philosophy, or rather that the true philosophical beginning in philosophy, or rather the true philosophical beginning, Difference, is in-itself already repetition’.
Common sense, good sense
But Descartes, the philosopher of radical commencement, is also the philosopher of representation par excellence. In a manner that both resonates with and diverges from Foucault’s account in The Order of Things,  and ignores the Derridean view of the cogito as ‘punctuated by a singular and unprecedented excess’,  Deleuze brusquely encapsulates this logic of subjective presupposition in the following terms: ‘Everybody knows, no one can deny, is the form of representation and the discourse of the representative.’  But who, and how, is the philosopher representing?
What place is this elaborate philosophical drama – the drama of the Meditations – supposed to let the philosopher occupy? To use the terminology of What is Philosophy?, which conceptual persona are we dealing with? In a sense – and we shall return to this feature of Descartes’s role in Deleuze’s overall characterization of philosophical practice – we are confronted with something like a degree-zero conceptual persona, a persona without personality, the idiot, the everyman, ‘the individual man endowed with his natural capacity for thought [as opposed to] the man perverted by the generalities of his time’. Not a man without qualities, but a ‘man without presuppositions’. The critique of Descartes demonstrates the extent to which Deleuze is unequivocally opposed to any philosophical anthropology founded on the elaboration of a theory of thought as a universally held capacity. His objection is precisely to that implicit, subjective presupposition which takes ‘the form of a natural capacity for thought which allows philosophy to claim to begin, and to begin without presuppositions’. And the paragon of such a ‘natural capacity’ is to be found at the very start of the Discourse on Method:Good sense is the best distributed thing in the world:
for everyone thinks himself so well endowed with it that even those who are the hardest to please in everything else do not usually desire more of it than they possess. In this it is unlikely that everyone is mistaken. It indicates rather that the power of judging well and of distinguishing the true from the false – which is what we properly call ‘good sense’ or ‘reason’ – is naturally equal in all men, and consequently that the diversity of our opinions does not arise because some of us are more reasonable than others but solely because we direct our thoughts along different paths and do not attend to the same things. For it is not enough to have a good mind; the main thing is to apply it well. 
This passage weaves together an ascription of natural equality (‘everybody thinks’) and a more-or-less pedagogical teleology (good application and choosing the right path). For Deleuze, such a dogmatic–didactic image of cognitive equality requires the participation of both common sense, understood as the natural accord of the faculties,  and good sense, conceived as the teleological (and ultimately moral or normative) determinant of such a natural usage. For Deleuze, ‘good sense is by nature eschatological, the prophet of a final compensation or cancellation’; it is an agency of distribution (‘on the one hand’, ‘on the other hand’); it ‘does not negate difference. On the contrary, it recognizes difference just enough to affirm that it negates itself, given sufficient extensity and time’; common sense is static and points beyond itself to good sense as the ‘dynamic’ instance, which takes as its point of departure ‘a difference at the origin of individuation’; they distinguish each other like recognition from prediction, like a qualitative synthesis of diversity and a quantitative synthesis of difference.
This de-differentiating, distributive, temporal function of good sense also has political overtones: ‘Good sense is the ideology of the middle classes who recognize themselves in equality as an abstract product.’  On the issue of the natural equality of thought, as it transpires from the Discourse on Method, one might confront the Deleuzean critique of the image of thought with an entire radical tradition of political anthropology or egalitarian rationalism: with Feuerbach’s definition of man in terms of his power to think the infinite; with Chomsky’s anarchist and overtly Cartesian elaborations on the notion of human nature; as well as with the cognitive or intellectual egalitarianism of recent authors such as Rancière and Virno. A brief but illuminating comparison can be made here with the Prison Notebooks of Antonio Gramsci, in which the couple good sense/common sense is also operant, and given a valence which is at once epistemological and political.
Gramsci famously starts from a thesis of generic intellectuality. In the Eleventh Notebook, he bases this thesis on a difference in degree (quantitative) and not in kind (qualitative), between the spontaneous philosophy of the masses (or i semplici, the simple ones) and elaborate world-views or ‘philosophies’ proper. This is why it is necessary, as he puts it, ‘to demonstrate that all men are “philosophers”, defining the limits and features of this “spontaneous philosophy”, belonging to “everybody”’. This spontaneous philosophy of everyman, which comes in different socio-historic guises, is in turn to be found sedimented in language, in the couple of common sense and good sense, and in popular religion or folk belief. Although Gramsci is sometimes equivocal about the difference between good sense and common sense – with the terms sometimes treated as synonyms, while elsewhere common sense is given a fundamentally negative collective connotation (in the sense of popular ignorance or ideology; Gramsci calls common sense the ‘“folklore” of philosophy’, an incoherent and subaltern aggregate ‘where you can find whatever you want’) and good sense is more akin to a Cartesian capacity – his schema does combine the two notions which are given the names common sense and good sense in Deleuze’s attack on the dogmatic image of thought. In other words, Gramsci advocates a radical variant of the combination of a universal capacity with a requirement for pedagogy that Deleuze condemns. In Gramsci, this pedagogy is intrinsically linked to the fate of the political party, the ‘Modern Prince’ and to the cultural project of hegemony (defined as the task of ‘overcoming a determinate “common sense” to create another which is more adherent to the conception of the world of the leading group’).  As Guido Liguori notes, Gramsci in this regard considers the ‘Enlightenment’ error to consist in inferring from the commonality of philosophy (the belief that everybody is a ‘philosopher’) the idea that men simply are equal.
The gap between capacity and pedagogy is here the space for the political becoming of equality, which in Gramsci takes unabashedly vanguardist tones.
In this regard, and contrary to the Deleuzean image of common sense merely as a bulwark for philosophies of transcendence and authority, Gramsci’s philosophy of praxis is aimed at the politicization of the category of common sense, and at envisaging it as the terrain of cultural, political and pedagogical transformation:
This means that common sense is an equivocal, contradictory, polymorphous concept and that to refer to it as evidence of truth is nonsense … common sense is crassly misoneistic and conservative, and to have managed to inject it with a new truth is proof of the force of expansion and evidence of such a truth. 
Common sense is thus treated as in a sense preintentional and, as Liguori notes, Gramsci’s position is ‘anti-subjectivist’ in the sense of cautioning against a belief in the spontaneous equality of minds and instead advocating the necessity of a political subject to organize the passage from mass intellectuality to a transformed common sense. Before closing this interlude, to which we will return once we tackle Deleuze’s political attack on Cartesian dualism, it is important to note that the kind of political anthropology of thought put forward by Gramsci – and possibly by other radically different figures who are nevertheless preoccupied with analogous problems, such as Chomsky or Virno – is not founded on the imputation ‘everybody knows’ but rather on the axiom that ‘everybody thinks’.
Image and plane
What, or rather who, does Deleuze oppose to this representational universalism of a ‘natural’ intellectual capacity? A kind of Bartleby-like figure, a conceptual persona who it would be fair to call ‘a real idiot’.
This is the strange figure – one would hardly call it a ‘subject’ – who escapes both subjective and objective presuppositions; who not only refuses to acknowledge the agreed taxonomies of concepts (‘rational animal’, and so on), but who starkly undermines the very presupposition of cognitive universality. This ‘individual full of ill will’ is someone ‘who neither allows himself to be represented nor wishes to represent anything’. 
It is worth noting that this figure, who Deleuze sees incarnated in the infamous and underground men of Shestov and Dostoevsky, is also accorded a kind of diagonal temporal register: ‘such a one is the Untimely, neither temporal nor eternal’, neither the obedient child of an objective culture nor the normal bearer of a linguistic capacity. Against those who see emancipatory potential in the subjective presupposition of cognitive universality (‘everybody knows’), Deleuze promotes the suspicion that such presupposition (or perhaps we should say such an imputation or ascription) of thought hides an ‘interest’, an interest precisely in representing the supposedly general capacities of thought, in speaking for others by speaking universally – a subtle and eminently political machination which is founded on the treatment of thought as a natural faculty and the thinker as endowed with the good will to channel its natural exercise. What is even more insidious is that such presuppositions are precisely not, in most cases, explicitly flagged; rather they are ‘propositional themes which remain implicit and are understood in a pre-philosophical manner’.  Where others might see this universal faculty as corrosive of hierarchies and inequalities, Deleuze sees a depotentialization and normalization of thought in ‘the implicit presupposition of philosophy’, ‘the idea of a common sense as Cogitatio natura universalis’. It is against this idea of thinking as a universally shared natural capacity that Deleuze unceasingly advocates the notion that we do not yet know what it means to think – or we do not know what thought can do (nor, indeed, who or what it is that thinks, a matter that could benefit from an exploration of the discussion of the ‘brain’ in What is Philosophy?). In a sense, then, the ‘image of thought’ is precisely something that cannot be ‘seen’, a kind of spectral presence that inhabits, in one way or another, and accompanied by all sorts of resistances and perversions, all of philosophy (except perhaps Spinoza or Nietzsche, though Deleuze and Guattari are ambiguous on this count). It is worth noting that – mirroring in a sense the unity and universality of thought that this dogmatic, representational image promotes – Deleuze does not observe a plurality of prejudices and compromises with opinion and generality as corrupting philosophical practice, but rather ‘a single Image in general which constitutes the subjective presupposition of philosophy as a whole’.  This is perhaps the peak of Deleuze’s Nietzschean intolerance towards the slavish collusions of philosophy with common sense, the moment for his call – later dulled if not retracted – for a thought that would be faithful to this radical ‘critique’ of the image, that would find a ‘true beginning’, ‘not in an agreement with the pre-philosophical Image but in a rigorous struggle against this Image, which it would denounce as non-philosophical’.
What happens in the shift from the hyper-critical incursion into the subjective presuppositions of thought in Difference and Repetition to the pedagogical unfolding of the conditions of conceptual creation in What is Philosophy? In other words, what happens between the image and the plane? Does Deleuze (here with Guattari) live up to the task of ‘a philosophical obstinacy with no ally but paradox’, which he declared in Difference and Repetition?
There, Deleuze had declared that what separates Descartes from the ‘commonsensical’ version of common sense, what ‘makes him a philosopher’, is the manner in which he erects the image of thought to a principle, so that even if ‘everybody’ ‘really’ knows that thought is a rare, unevenly distributed and difficult thing, it may nevertheless be ‘the easiest in principle’. And what makes it easiest in principle is a certain transcendental model which enacts the image via ‘recognition’. As Deleuze writes:
Recognition … relies upon a subjective principle of collaboration of the faculties for ‘everybody’ – in other words, a common sense as a concordia facultatum; while simultaneously, for the philosopher, the form of identity in objects relies upon a ground in the unity of a thinking subject, of which all the other faculties must be modalities. This is the meaning of the Cogito as a beginning: it expresses the unity of all the faculties in the subject; it thereby expresses the possibility that all the faculties will relate to a form of object which reflects the subjective identity; it provides a philosophical concept for the presupposition of a common sense; it is the common sense become philosophical. For Kant as for Descartes, it is the identity of the Self in the ‘I think’ which grounds the harmony of all the faculties and their agreement on the form of a supposed Same object. 
As I have already suggested, a number of the antiCartesian themes broached in Difference and Repetition return in What is Philosophy? But, just as Deleuze and Guattari highlight both the history and the becoming of a concept (whereby the first implies the borrowings and transformation of previous conceptual constellations, and the second the relation to concepts situated on the same plane), we could say that there is both a history and a becoming to Deleuze’s own relation to Descartes, a set of shifts, ambivalences and short-circuits which prevent him from reverting to a merely dogmatic anti-Cartesianism. In keeping with the most familiar image of Descartes, Deleuze and Guattari introduce him in terms of a discussion of what it is to begin in philosophy. They write: ‘Even the first concept, the one with which a philosophy “begins,” has several components, because it is not obvious that philosophy must have a beginning, and if it does determine one, it must combine it with a point of view or ground.’  Within this framework, the epitome of the concept of beginning and of a first concept – the Cartesian Cogito – is approached by Deleuze and Guattari as a kind of testing ground for the constructivist phenomenology of the concept which they trace in the first half of What is Philosophy? Whereas the passage from the Cartesian Cogito to the Kantian subject might belong to the discontinuous history of the concept (as Étienne Balibar has recently explored, pointing out that the Cartesian subject, rather than Cogito, is a retroactive post-Kantian invention),
Deleuze and Guattari’s ‘Example I’ is an investigation of the timeless becoming of the Cogito qua concept – to be understood in terms of its components or variations, and the bridges that it may build towards other concepts (world, God, and so on).
This micro-phenomenology of the concept is particularly provocative inasmuch as it eschews two other approaches to the Cogito – one which would take the becoming of the Cogito in terms of the narrative course of Descartes’s own Meditations and its dramatic moments (e.g. ‘I will now shut my eyes, stop my ears, and withdraw all my senses’), and another which would see in it the basis for an exacting formalism.
In shifting the framework from the critical to the constructive, Deleuze certainly does not abandon some of the key perspectives on Descartes developed in his earlier work.
However, in proposing together with Guattari an allencompassing theory of the concept, Deleuze obviously felt the need to put constructivism to the test, enlisting his phenomenology of the concept in accounting for what should have been the most recalcitrant concept, the one that – if we follow Difference and Repetition – inaugurates the modern embodiment of the image of thought. Thus, in mapping the components of the Cogito (doubting, thinking, being) and diagramming their inner dynamics and ‘condensation’, Deleuze and Guattari present the Cogito qua multiplicity. In what sense does this seemingly ecumenical choice (the Cogito as just another ‘example’ of a generalized philosophical creativity) clash with the elaborate process whereby, in Difference and Repetition, the ‘I’ came to be fissured and its place occupied by swarming ‘factors of individuation’?  What does it mean to think Descartes’s Cogito as the ‘event of thought’?
We should not fail to notice both the apparent capitulation of Deleuze’s revolutionary project of a thought without an image and, at the same time, the sheer perversity of treating Descartes in this register.
Rather than rehashing the condemnation of Descartes as the purveyor of an insidiously disempowering brand of universality, in which the ‘clear and distinct’ shackles thought to representation and to the scientific demands of extensity, as well as the spiritual demands of interiority, Deleuze now reinterprets the very hinge of the Cartesian system as articulated in terms of ‘intensive ordinates’, components that are ‘arranged in zones of neighbourhood or indiscernibility that produce passages from one to the other and constitute their inseparability’.  The ‘clear and distinct’ and the foundation of mathematical extension and rational representation are mined from the inside, bringing to the surface something like Descartes’s repressed constructivist unconscious. What is disarming, however, is that in this odd combination of dispassionate diagram and subversive ventriloquism, from which the antagonism of ‘The Image of Thought’ is largely absent, there is a kind of ‘absolute relativism’ at stake. As Deleuze puts it: ‘There is no point wondering whether Descartes was right or wrong.’  But does this not constitute a kind of aestheticizing repudiation of the very radicality of a project for which truth and falsity, correctness and inadequacy, were crucial concepts, ones not only involved in the internal becoming of the philosophy, but part of a history which, if we follow recent research on the role of Cartesianism in the radical Enlightenment, was in many ways also political? When Deleuze and Guattari write that ‘Cartesian concepts can only be assessed as a function of their problems and their plane’, is this to say that we should simply bracket the very exacting and ‘totalizing’ demands they make on thought – the manner in which Descartes wages war on problems which he thinks no longer have any right to exist? If a thought, such as that of Descartes, wants to wipe the slate clean of much of what it sees as corrupting verbiage and unthought, is it really possible to investigate the constructivist machinations of his thinking, and at the same time assume that it can be maintained on ‘its own plane’, with ‘its own problems’? Deleuze and Guattari ask rhetorically: ‘Is there one plane that is better than all the others, or problems that dominate all others. Nothing at all can be said on this point.’ Is this quietism a mere gesture or a subterfuge (behind which we can clearly see, in What is Philosophy? itself, that Spinoza is better than Descartes, inasmuch as he included the thinking of constructivism within his ontology and ethics)?
In any case, it is interesting that the very elements that served to damn Descartes in some of the earlier work are recuperated here as bona fide philosophical inventions; for instance, when Deleuze and Guattari refer to the introduction of ‘prephilosophical understanding’ as a ‘very novel distinction’, ‘a plane that requires a first concept that presupposes nothing objective’.  In attending to the dynamics of conceptual creation, rather than the image of thought, Deleuze and Guattari present the prephilosophical not as a surreptitious enemy of thought, but as a plane, and, we might suppose, a variety of immanence, thereby signalling a break of sorts, or at least a retreat, vis-àvis the unsparing critique of the image of thought in Difference and Repetition:If philosophy begins with the creation of concepts, then the plane of immanence must be regarded as prephilosophical. It is presupposed not in the way that one concept may refer to others but in the way that concepts themselves refer to a nonconceptual understanding. Once again, this intuitive understanding varies according to the way in which the plane is laid out. In Descartes it is a matter of a subjective understanding implicitly presupposed by the ‘I think’ as first concept; in Plato it is the virtual image of an already-thought that doubles every actual concept.
Heidegger invokes a ‘preontological understanding of Being’, a ‘preconceptual’ understanding that seems to imply the grasp of a substance of being in relationship with a predisposition of thought. In any event, philosophy posits as prephilosophical, or even as nonphilosophical, the power of a One–All like a moving desert that concepts come to populate.
Prephilosophical does not mean something preexistent but rather something that does not exist outside philosophy, although philosophy presupposes it.
These are its internal conditions. 
Thus, rather than a critical dismantling of the dogmatic image of thought, What is Philosophy? unfolds an intra-philosophical theory of thought (and of the role of non-philosophy in the constitution of thought).
In this theory, Descartes has full rights of speculative citizenship, to the extent that the very element which singled him out as the villain of Difference and Repetition – the role of subjective presupposition as a false beginning of a philosophy shorn of dependence – becomes in What is Philosophy? paradigmatic of philosophical activity itself. Even though Spinoza remains the Prince or Christ of philosophy, Descartes is thus emblematic of the manner in which philosophy constructs a plane of immanence in presupposing and introjecting its own outside.
Dualism and its discontents
In tracking this shift within Deleuze’s appropriation of Descartes – a shift which, by inserting Descartes into different philosophical problematics seems to draw almost diametrical consequences out of the very same references and terms – I have yet to confront head-on the issue of Deleuze’s role vis-à-vis the kind of anti-Cartesian consensus that Slavoj Žižek, among others, famously lambasted as the very apex of university ideology in the preface to The Ticklish Subject; parodically writing of the Cartesian subject as the ‘spectre haunting Western academia’. The term which, with Pavlovian inevitability, seems to set off the antiCartesian reflex is of course dualism – primarily as mind–body dualism, but also in its vague acceptation as the stigma of hierarchy, domination, division, separation and sundry other terms marked by the spirit of the age with a negative valence. Dualism, understood in particular in terms of the separation of the Cogito from the world, has however also had a number of advocates, apologists or at the very least historical contextualizations. Within the panorama of contemporary Continental philosophy, three interesting ways of defending dualism (or what more broadly we might call a thesis of separation) against its holist, monist or materialist detractors can be identified.
The first is historical-scientific and can be encountered, for instance, in Karl Löwith’s God, Man and World in Metaphysics from Descartes to Nietzsche. In this, one of his very last texts, written in 1967, Löwith prolongs his polemic with Heidegger into a spirited defence of Descartes’s dualism as a recognition of the externality, independence and objectivity of the world.
In this interpretation Descartes’s dualistic separation of the Cogito from the world is actually a far less unworldly option than the one taken by Heidegger:
Who then jumps over the world with both feet? The student of natural sciences Descartes, or rather the ex-theologian Heidegger, who only counts those aspects of the world that can be referred to our emotional situation, to anxiety and care? Which of the two ‘unworlds’ the world? Descartes, who as a naturalist takes his cue from the consistency of a world that remains stable, or Heidegger, who would like to explain the world of nature on the basis of its lost link with our environment? 
In this conception, Descartes’s dualism has the ‘naturalist’ virtue of what Löwith calls an ‘anti-historic sensibility for the things themselves’, by refusing to consider cognition as constitutive of the objective world and even by incorporating certain elements of a Christian thought which abstracts from worldly experience.
A second political manner of valorizing or contextualizing Descartes’s infamous dualism is to be found in Antonio Negri’s Political Descartes, originally published in 1970. Unlike those who read Descartes as a mere mechanicist or theologian of transcendence, Negri reads dualism (or separation) as an intra-philosophical effect of the collapse of the Renaissance humanist attempt at thinking and practising an immanence of man to the cosmos; an experience which according to Negri has a clear class character – the defeat of the emergent bourgeoisie as a hegemonic class. The separation of the Cogito or subject is viewed in terms of the struggle of bourgeois essence to project its power and productivity into worldly existence. Descartes provides the ‘reasonable ideology’ of a bourgeoisie experiencing its post-humanist defeat because it affirms its separation (the inefficacy of the bourgeoisie as a worldly power) but maintains the need to consolidate its subjective potency and prepare its projection onto, and possession of, the world, rather than accepting the grim metaphysics of mechanicism and its acceptance of transcendence and authority, as in Hobbes, whose polemic with Descartes Negri reads in these terms.
The refusal of an unproblematic relation between the I and the world, the refusal of any utopia or myth of possession, is an index, for Negri, of Descartes’s sober recognition of the separation of the bourgeois subject in the world of the 1600s. Thus man, as a thinking thing, is refounded in this separation and given ontological weight and potency in dualism. As Negri writes: ‘if the general identity of essence and existence, of the I and the world, and the univocal universal predication of being are not possible, this new foundation of man nevertheless represents a solid starting point, a rich potential for development that is only awaiting to unfold. 
A third manner of valorizing dualism is to be found in the Lacanian ‘return to Descartes’ and specifically in the version of this return recently advocated by Slavoj Žižek, who sees the Cartesian subject in its modern form not as a substantial res cogitans, but as a voided subject ‘out of joint’, ‘excluded from the “order of things”, from the positive order of entities’. Žižek accordingly identifies the Cartesian subject as a purely ‘excremental subject’, linked, importantly, to a political ontology of the proletariat:
For Marx, the emergence of working-class subjectivity is strictly codependent to the fact that the worker is compelled to sell the very substance of his being (his creative power) as a commodity on the market, that is, to reduce the agalma, the treasure, the precious kernel of his being, to an object that can be bought for a piece of money – there is no subjectivity without the reduction of the subject’s positivesubstantial being to a disposable ‘piece of shit’ … if the Cartesian subject is to emerge at the level of the enunciation, he is to be reduced to the ‘almostnothing’ of a disposable excrement at the level of the enunciated content. 
In significant respects, Deleuze seems to represent what is almost a caricature of the now tiresome attack on dualism, which, as Žižek aptly notes, has become a rare point of agreement between the most disparate and otherwise hostile fractions of academia, from cognitive science to feminism, from postcolonial studies to post-analytic philosophy. At the peak of his anti-dualist fervour, in his 26 March 1973 seminar on ‘Dualism, Monism and Multiplicities (Desire–Pleasure–Jouissance)’, Deleuze presents us with some potent slogans: ‘Dualism is what prevents thought’; ‘Dualism always wants to deny the essence of thought, namely, that thought is a process’; ‘The only enemy is two’; ‘Wherever we leave the domain of multiplicities, we once again fall into dualisms, i.e. into the domain of non-thought, we leave the domain of thought as process.’ But what is the grounding structure of this dualism? It is precisely the one indicated by Žižek himself – which is, after all, not surprising, inasmuch as for Deleuze, ‘today we are talking about Descartes, i.e. Lacan’, thinkers joined by the ‘repugnant thought of the cogito’. Dualism, in this seminar, is thus identified as the dualism of a subject of enunciation and a subject of the statement (or the enunciated). Moreover, dualism is definitive of what Deleuze calls ‘Western thought’, an apparatus whereby statements are taken to exist individually, and the production of these statements, rather than originating in what he and Guattari dubbed a collective assemblage of enunciation, is produced in and by a subject: Cogito: this means that every statement is the production of a subject. It means that firstly; and secondly, it means that every statement splits the subject that produces it. Lacan is the last Cartesian.
Then every statement refers to a subject, and every statement splits, cuts separates the subject that produces it. 
The formula cogito ergo sum is what disengages the subject of enunciation from the subject of the statement, since from ‘I walk’ (subject of the statement) no subject of enunciation could be extracted. All dualisms, according to Deleuze, are corollaries of this fundamental dualism of enunciation. And the hatred of dualism is deeply political (or, less charitably, moral) in kind. The sinister aspect of this seemingly formal dualism is to be encountered at the level of the powereffects of the introduction of a gap in the subject – the very gap we encountered in the question of common sense and good sense, and in the idea of a pedagogy of intelligence that comes along with supposedly egalitarian rationalism. Dualism is the philosophy of democratic discipline whose hypocrisy lies in the idea that ‘it is you who command, i.e. you who will accede to the commandment to the degree that you submit yourself to an order, which you are not subject to without also being its legislator. This is the famous order of democracy.
You are the legislator insofar as you are the subject.’ This is a point in which the history of the subject, as the subject which subjects himself to his ‘own’ immanent-transcendent legislation, leads straight from Descartes to Kant. Not just the vicious circle of democratic sovereignty, but all social repression, all its saloperies as Deleuze puts it, seems to be founded on this dualism of the statement.
Deleuze takes the statement ‘Me as a human being’ as an example. As he writes All social functions are constructed on that, all repressive functions are constructed on this cleavage; me as a human being, you understand, but as a father, I must act! Me as a human being; I’m on your side; but as a cop, I have to apply the law!’  But is dualism to be universally condemned, as the repugnant castration of desire in the split subject? Again, if a lesson is to be drawn from the ‘becoming’ of Deleuze’s relationship to Descartes, it is that the shift in the problem which Deleuze is addressing in a given moment or text metamorphoses the function and figure of the philosophers involved, and this seems to affect Descartes’s standing in a particularly strong manner. The advance of Kant’s formulation of the subject over that of Descartes – and incidentally, we should note that Žižek himself accepts that his own so-called Cartesian subject is profoundly post-Kantian – is in fact based on the excess of substantiality and insufficient possibility for splitting and thus for the proliferation of difference in Descartes.
The introduction of the determinable – that is, of time – between determination and the determined, and the consequent disjunction between spontaneity and receptivity, also split the subject but in a manner which Deleuze thinks is a genuine ‘progress’ in the conception of subjectivity.
It is the pure and empty line of time that traverses, that operates this kind of crack in I … Time has become the limit of thought and thought does not cease to deal with its own limit. Thought is limited from the inside. There is no longer an extended substance that limits thinking substance from outside, and which resists to thinking substance, but the form of thought is entirely traversed, cracked like a plate, it is cracked by the line of time. It makes time into the interior limit of thinking itself, that is the unthinkable in thought … one finds a kind of tension between two forms … on the one hand the active form of determination, on the other the intuitive or receptive form of the determinable – time. The two are absolutely heterogeneous to one another, and nevertheless there is a fundamental correlation: the one works in the other. It is in itself that thought harbours that which resists thought. 
We are thus provided, at different points in Deleuze’s oeuvre, with two splits, two dualisms, as it were, one a castrating dualism of hypocritical authority based on the linguistic split between subject of the statement and subject of enunciation, the other a temporal split, or crack, between spontaneity and receptivity.  While the first subjects us to the authority in ourselves, in a vicious circle of auto-subjection, the second introjects an outside, ‘the unthinkable in thought’, within the very experience of thought. But we should note that in this seminar, as well as others, it is fullness and not dualism per se which is the stigma of Descartes’s thought, and, moreover, that the total political continuity between Descartes and Kant with regard to the self-imposition of authority is ignored in favour of the question of thought’s outside (even though, confusingly,
Deleuze also argues that the Meditations is ‘the first book that introduces time into philosophical discourse’, as in the seminar of 28 March 1978). Here Descartes is not a philosopher of a gap into which authority and teleology insert themselves, but a figure of plenitude, a bad egg, so to speak:
there is a gap, a fracture in the Cogito. In Kant the Cogito is completely cracked. It was full like an egg in Descartes, why? Because it was surrounded and bathed by God. But with constitutive finitude I walk on two legs, receptivity and spontaneity, this is really the fracture at the heart of the Cogito. 
In conclusion we could say that there is a fracture, or rather a plurality of volatile and fugitive faultlines, at work in Deleuze’s several engagements with Descartes’s thought, a number of shifts which are conceptual, on the one hand, and strategic or polemical, on the other. Attention to the motivations and effects of these shifts can perhaps attenuate the image, stridently proposed by Deleuze himself at certain junctures, of his philosophy as a kind of prolonged anti-Cartesian war cry. Or, rather, it can allow us to differentiate what Descartes might stand in for when it comes to what Deleuze regards as the transcendental illusions of thinking itself. At this level, to address the two concerns of this article, it seems that while Deleuze can accommodate certain varieties of dualism and splitting, the very notion of a universal cognitive capacity remains anathema to his thought. If nothing else, that humanist-egalitarian image of reason remains alien to any possible Deleuzean rationalism.
This is a revised version of a paper delivered at the conference ‘Deleuze and Rationalism’, Centre for Research in Modern European Philosophy, Middlesex University, 14–15 May 2007.
1. ^ Gilles Deleuze, Difference and Repetition, Athlone,
London, 1995, p. 132.
2. ^ François Zourabichvili, Deleuze: Une philosophie de l’événement, PUF, Paris, 1994, p. 17.
3. ^ Slavoj Žižek, The Ticklish Subject, Verso, London, 1999.
4. ^ The passage that Deleuze is referring to is the following: ‘What then did I formerly think I was? A man. But what is a man? Shall I say “a rational animal”? No; for then I should have to inquire what an animal is, what rationality is, and in this way one question would lead me down the slope to other harder ones, and I do not now have the time to waste on subtleties of this kind’ (René Descartes, Meditations on First Philosophy, ed. John Cottingham, Cambridge University Press, Cambridge, 1996, p. 17).
5. ^ Deleuze, Difference and Repetition, p. 129.
6. ^ Michel Foucault, The Order of Things, Routledge, London 2001, pp. 55–64.
7. ^ It is worth noting Deleuze’s insensitivity, on this matter, to that which in the cogito exceeds, or threatens to exceed, any premiss or presupposition, the risk that haunts the experience of thought: ‘The extent to which doubt and the Cartesian Cogito are punctuated by this project of a singular and unprecedented excess – an excess in the direction of the nondetermined, Nothingness or Infinity, an excess which overflows the totality of that which can be thought, the totality of beings and determined meanings, the totality of factual history – is also the extent to which any effort to reduce this project, to enclose it within a determined historical structure, however comprehensive, risks missing the essential, risks dulling the point itself’ (Jacques Derrida, Writing and Difference, University of Chicago Press, Chicago, 1980, p. 57).
8. ^ Deleuze, Difference and Repetition, p. 130.
9. ^ René Descartes, The Philosophical Writings of Descartes, vol. 1, ed. John Cottingham, Robert Stoothoff and Dugand Murdoch, Cambridge University Press,
Cambridge, 1985, p. 111.
10. ^ Admittedly, Deleuze’s treatment of common sense relies more on his discussion of Kant (Gilles Deleuze, Kant’s Critical Philosophy, University of Minnesota Press, Minneapolis, 1985, p. 21) than on Descartes’s texts, where it is used relatively sparingly, either as the generically held capacity or to describe the specific functioning of the pineal gland as the transducer between mind and brain. For the ‘common’ sense as pineal gland, see Descartes, The Philosophical Writings of Descartes, pp. 41, 161. For the more generic meaning, see The Search for Truth: ‘Provided we have proper direction, all we need for discovering the truth on the most difficult issues is, I think, common sense, to give it its ordinary name’ (René Descartes, The Philosophical Writings of Descartes, vol. 2, ed. John Cottingham, Robert Stoothoff, Dugand Murdoch and Anthony Kenny, Cambridge University Press, Cambridge, 1991, p. 412); ‘The only master he follows is common sense, and his reason has not been marred by any false preconceptions’ (ibid., p. 420).
11. ^ Deleuze, Difference and Repetition, pp. 223–7.
12. ^ Guido Liguori, ‘Senso comune’ e ‘buon senso’ nei Quaderni del carcere, 2005, www.gramscitalia.it/senso.htm [archive], p. 12. ‘After having based oneself on common sense to show that “everybody” is a philosopher and that it is not a matter of introducing ex novo a science into the individual life of “everybody” but to innovate and make “critical” a pre-existing activity’ (ibid., p. 16).
13. ^ Ibid., p. 10. Incidentally, it is interesting to note that Gramsci specifically links the concept of common sense to a French historical frame: ‘In French philosophical culture there are more treatments of “common sense” than in other cultures: this is due to the “nationalpopular” character of French culture; that is to the fact that there intellectuals tend, more than elsewhere, because of determinate historical conditions, to get close to the people to guide it ideologically and keep it tied to the leading group’ (ibid., p. 12).
14. ^ Deleuze, Difference and Repetition, p. 130.
15. ^ Ibid., p. 131.
16. ^ Ibid., p. 132.
17. ^ Ibid., p. 133.
18. ^ Gilles Deleuze and Félix Guattari, What is Philosophy?, Verso, London, 1996, p. 15.
19. ^ Deleuze, Difference and Repetition, p. 257.
20. ^ Deleuze and Guattari, What is Philosophy?, p. 25.
21. ^ Ibid., p. 27.
22. ^ Ibid., p. 26.
23. ^ Ibid., 1996, p. 41.
24. ^ Karl Löwith, Dio, Uomo e Mondo nel a metafisica da Cartesio a Nietzsche (1967), Donzelli, Rome, 2000, pp. 42–3.
25. ^ Antonio Negri, Political Descartes: Reason, Ideology and the Bourgeois Project, trans. Matteo Mandarini and Alberto Toscano, Verso, London, 2007, pp. 216–17.
26. ^ Žižek, The Ticklish Subject, p. 157.
27. ^ Gilles Deleuze, ‘Dualism, Monism and Multiplicities (Seminar of 26 March, 1973)’, Contretemps 2, 2001, p. 93.
28. ^ Ibid., p. 104.
29. ^ Gilles Deleuze, seminar, 28 March 1978, Les Cours de Gilles Deleuze, www.webdeleuze.com. [archive]
30. ^ On Deleuze’s own proliferation of dualisms, especially in his work with Guattari (between the molar and the molecular, the smooth and the striated, the nomad and the state, and so on), and their tendency to reify into ethical and ideological binaries, see Fredric Jameson, ‘Deleuze and Dualism’, in Valences of the Dialectic, Verso, London, 2009, pp. 198–200.
31. ^ Gilles Deleuze, undated 1987 seminar on Leibniz, available at www.webdeleuze.com/php/texte.php?cle=132 [archive]&groupe=Leibniz&langue=1.