Gilles Deleuze’s Philosophy of Nature: System and Method in What is Philosophy?

An Open System: Becoming and History

The system set out in What is Philosophy? has two crucial properties: firstly, it is an open system in which philosophy is conjoined to the historical preconditions; secondly, it is a system in motion in which philosophy intersects and connects with the two other forms of thought or creation. With regard to the first property, Deleuze (1995b: 31–32) asserted in a conversation in 1980 that art and science are in the process of forming or engaging with open systems. As far as science is concerned, Deleuze was thinking primarily of the spontaneous processes of conversion and organization by which current physics and biology explain the origin of the universe and the living beings on our planet. Such processes, which can occur in disordered and chaotic mixtures under certain preconditions, are irreversible. They produce what the chemist Ilya Prigogine calls dissipative structures – structures that exchange matter and energy with their environment in order to keep their sensitive, fluctuating order from disintegrating (see Kauffman, 1995: 20–23).

In Order Out of Chaos, Prigogine and Stengers (1984: 93–96, 213, 302–303) contrast the classical world of dynamics and the modern world of thermodynamics, explaining the extent to which Leibniz belongs to the first world, Whitehead to the second. Whitehead asserts that actual entities enter into variable relations with one another, from which they gain and modify their individuality. By means of these relations, they shape a processual world that permits the genesis of new entities and the extinction of existing ones. Unlike Leibniz’s monadology, Whitehead’s cosmology lays out a system of irreversible laws that presupposes chaos and hence depends on the arrow or direction of time. His cosmology rejects the static universe of dynamics in favor of an open universe in which nature, starting from certain preconditions, advances gradually and more or less accidentally, or – to borrow a phrase from Slavoj Žižek’s (1996: 111) comments on quantum physics – in favor of ‘a universe whose creation is not yet completed’. In The Fold, Deleuze (2006: 86–93, 157–158) similarly proposes a contrast between two worlds, with Leibniz belonging to one and Whitehead to the other. Discussing Whitehead, he refers to a chaosmos that involves discordant or incompossible relations and renews and modifies itself along divergent bifurcations. Our world, for which What is Philosophy? devises a philosophy of nature, can be characterized as a chaosmos that constantly rises anew from chaos, with all the things and living beings, and takes up the unexpected, looking toward an uncertain future.

The system presented in What is Philosophy? is the system of a nature undergoing the process of becoming at the same time as it changes perpetually and irreversibly with history. Deleuze and Guattari call this nature, which stands for the renunciation of the eternal, of an everlasting and unalterable Being, earth. They criticize Heidegger, whose Being knows no becoming, which explains why in Heidegger there are still rigid conjunctions between Being and beings, conjunctions predefined by the succession of ages (Deleuze and Guattari, 1994: 94–95; see Heidegger, 2002: 57). Earth and its territories, the movements with which the territories arise and elapse, or are adopted and abandoned on earth, allow Deleuze and Guattari to build their philosophy of nature upon a doctrine of movement and as a geophilosophy or nomadology that fits our modern world. ‘The earth is not one element among others but rather brings together all the elements within a single embrace while using one or another of them to deterritorialize territory’ (Deleuze and Guattari, 1994: 85, see 1987: 509–510). From chaos and its vicissitudes, earth wrests movements of various types with which it generates our chaosmos, where chaos extends to the farthest corner of even the most stable parts. Earth is both creating nature and created nature: it is ‘deterritorializing and deterritorialized’, as Deleuze and Guattari (1994: 85) write, remembering Spinoza’s distinction between natura naturans and natura naturata. It acquires its immanent creative powers from the movements that it extracts from chaos. In any case, earth must be regarded as a kind of nature whose nature itself, so to speak, is mutable, continuously becoming and changing. A new earth – Deleuze and Guattari repeatedly address a new earth to come (pp. 88, 99, 101, 108–109) – is thus by its nature a new nature.

In contrast to the classical world, which saw its cause or foundation in an everlasting and unalterable Being, and historical beings as dependent on that Being, our modern world relies on assemblages, made up of movements of various types, through which actual entities are conjoined to an infinite becoming. Therefore, there is no longer a one-sided relationship between Being and beings, but mutable transitions between the movements of becoming and those of history, which intersect and conjoin. These mutable transitions result from events, which are configured by concepts. Concepts give form to virtual events as they undergo an infinite becoming and delimit them from each other in such a way that they close off and condense into preindividual intensities (pp. 32–34). Thus, concepts draw the virtual so close to the actual that, starting from the preindividual intensities, events can actualize and individuate themselves. Events always retain a virtual half of the entities in which they actualize, carrying it into an infinite becoming (p. 156).

Actual entities engage in an unceasing process of exchange with the events that they integrate into the realm of the actual and thereby convert into concrete individuals (Deleuze, 1997a: 70). This actualization and individuation are determined by the finite movements of history: ‘What History grasps of the event is its effectuation in matters of fact or in lived experience; but the event in its becoming, in its own specific consistency, in its self-positing as concept, escapes History’ (Deleuze and Guattari, 1994: 110, translation amended). Through a ‘multiplicity of local and partial integrations’, as Deleuze (1988a: 75) emphasizes with reference to Foucault’s dispositives of power, the movements of history produce various regimes of opinion, which stabilize the formations of history by ensuring that the actual entities align with the prevailing power relations. Accordingly, opinions are not simply beliefs or habits of thought that one follows as long as they correspond with one’s own interests and needs, but rather modes of existence to which one corresponds both in one’s thought and feeling, and in body and action (Deleuze and Guattari, 1987: 257). All individuals are subordinated to the all-encompassing strategy of opinion and its regimes, through which life functions.

This explanation of how individuation is prepared and executed is clearly influenced by Raymond Ruyer and Gilbert Simondon, both of whose philosophies intersect with knowledge drawn from biology and technology. In What is Philosophy?, Deleuze and Guattari explicitly refer to Ruyer’s absolute surfaces, which reinvent Leibniz’s monads (Deleuze and Guattari, 1994: 21, 210; see Ruyer, 2016: 90–103). Consistent events configured by concepts emerge from their own components, which they condense into absolute surfaces (Deleuze and Guattari, 1994: 11–12). This makes them – to use a biological term coined by Humberto Maturana and Francisco Varela – autopoietic (see Thompson, 2007: 43–49, 97–101), that is to say, they posit and maintain themselves and engender a consciousness of their own components, and at the same time of themselves, as the inseparable bonds of those components. Ruyer’s absolute surfaces are unities of an internal activity, which immediately acquaints them with the presence of their details: they are absolute domains of self-survey or in auto-overflight. Just as for Whitehead (1968: 150) ‘the notion of life’ implies first and foremost ‘a certain absoluteness of self-enjoyment’, for Ruyer (2016: 94) the absolute survey ‘is the key not only to the problem of consciousness but also to the problem of life’. By means of the self-survey, the absolute surfaces grasp its details at one stroke, without submitting them to a presupposed transcendent unity or setting them in a relation to an external reference point (see Grosz, 2017: 215–221). For Deleuze and Guattari (1987: 281–282), the plane of philosophy on which concepts are created is a plane of immanence of concepts because it knows no transcendent principle or law that determines the creation of concepts, either from without or covertly from within.

Concepts do not convey eternal and universal essences to which we may trace back the properties instantiated by individuals. Concepts are themselves created and form singular events, which are actualized in existing things and living beings. Deleuze and Guattari (1987: 49–51, 57–58) borrow from Simondon’s exegesis of the physico-chemical process of crystallization in order to formulate their perspective on actualization and individuation. Just as the seeds of crystallization modulate growth, events formed by concepts are the starting points for actualization and individuation. The crystalline seeds serve as pieces of information during crystallization; they modulate the metastable solutions that receive their information and continue to grow (Simondon, 2005: 85–91; see Barthélémy, 2005: 143–158). Information never exists on its own but is always given only in the process of transmission and in reference to a system, which is the sole context where it is information in the first place. Accordingly, there are no events configured by concepts that are not conjoined with actual entities or movements of history. Events are not only conjoined to those entities that engage in a process of exchange with them while effectuating them, but also to other entities to which they nevertheless contain allusions (Deleuze and Guattari, 1994: 159–161).

Deleuze (1995b: 32) indicated in the aforementioned conversation of 1980 that a philosophical system or a set of concepts is an open system ‘when the concepts relate to circumstances rather than essences’. In an open system, concepts are used not to define eternal and universal essences, but to bring forth events that are conjoined with historical preconditions. In the 1980s, Deleuze (2006: 89, see 1997b: 3, 2007a: 304, 2007b: 344) repeatedly pointed to a problem that he regarded as signaling such a ‘teleological conversion of philosophy’. He stressed that Leibniz faced this problem, and that it came to haunt Bergson and Whitehead. The problem was, as Deleuze (2006: 89) put it, ‘not how to attain eternity, but in what conditions does the objective world allow for a subjective production of novelty, that is, of creation’. In What is Philosophy? Deleuze and Guattari address the same problem mainly by explaining how we can succeed in creating concepts and thus form new events of things, living beings and lived experiences. To achieve this, however, philosophy depends on science and art, both of which consist in creative activities.

A System in Motion: Three Forms of Creation

The system presented in What is Philosophy? has philosophy intersect and connect with the other two ‘forms of thought or creation’ (Deleuze and Guattari, 1994: 208). By means of three specific planes, nature (or earth) wrests different movements from chaos and uses them to generate our chaosmos. Deleuze and Guattari’s theory of the planes draws on the attributes and powers that Spinoza ascribes to God. In A Thousand Plateaus, they explicitly describe these attributes as types of the plane of consistency (Deleuze and Guattari, 1987: 153). For Spinoza, the attributes are infinite forms of Being that are common to God and all creatures and provide the conditions for God to express his powers by calling forth his creatures. Proceeding from Spinoza’s attributes, Deleuze and Guattari (1994: 48) devise the plane of philosophy, which is in turn the model for the plane of art and that of science.

Each of the three planes filters those movements from chaos that will endow it with the power corresponding to those same movements. Each plane provides the internal conditions for the creative activity with which it rises to become a creative power. In addition, each of the three planes constitutes a realm of reality that is associated with the plane’s particular movements. Through the philosophical plane of consistency, the power of conceiving unfolds by creating concepts. This plane constitutes the realm of various intensities or of absolute surfaces, a realm in which concepts posit their objects, namely, consistent events (pp. 21, 210–211). The plane of art is the plane of composition, through which the power of feeling unfolds by creating sensations. This plane constitutes the realm of an interplay of forces, in which sensations compose monuments or compounds of sensations (pp. 211–213). The plane of science, finally, is the plane of reference, through which the power of knowing unfolds by creating scientific functions. It constitutes the realm of energy and mass, where each entity is bound to an extensive spatial order and continuous sequence in time (pp. 119, 121, 214–215). ‘With its concepts, philosophy brings forth events. Art erects monuments with its sensations. Science constructs matters of fact with its functions’ (p. 199, translation amended).

The three realms of reality are not three realms of Being that belong to God, but ‘the realities produced on the planes that cut through the chaos’. Deleuze and Guattari also call them the ‘three daughters’ of chaos (p. 208). Thus, the three planes enable a mutual immanence of creating and created nature, without assuming a divine Being. These planes produce a multibranched network: ‘The three thoughts intersect and intertwine but without synthesis or identification … A rich fabric of correspondences can arise between the planes’ (pp. 198–199, translation amended). As a consequence of the intersections and connections, every single assemblage belongs simultaneously to all three realms constituted by the three planes. An actual entity as such is one of three phases or states of an assemblage, which in its other two phases remains preindividual and virtual (Deleuze and Guattari, 1987: 225). The concrete individual is precisely that phase in this ternary instance which arises in the realm of the plane of reference.

As preparatory work for the renewal of his conception of the assemblage, first of all Deleuze avails himself of the examination of Foucault’s dispositives in the 1980s. Here, Deleuze foreshadows what becomes critically important in the theory of the planes, namely that each plane constitutes a realm of reality that accompanies its own movements, and that each plane acquires a power in accordance with these movements. Firstly, he makes it clear that an assemblage always belongs to all three realms, each of which is produced by one of the axes ‘that all intersect and entangle’ (Deleuze, 2007b: 342, translation amended) and extend beyond any single assemblage. Like Foucault, who distinguishes between the axis of knowledge, the axis of power and the axis of subjectivity, Deleuze speaks of ‘three “ontologies”’, but goes on to call the three realms three figures of Being: ‘Knowledge-Being’, ‘Power-Being’ and ‘Self-Being’ (Deleuze, 1988a: 114; see Foucault, 1997: 262–263). Secondly, he explains that the three axes are ‘the triple root of a problematization of thought’ (Deleuze, 1988a: 116; see Foucault, 1990: 10). In sum, we can say that, for Deleuze, the three axes define three problematic fields and constitute the internal conditions under which a historical formation with all the dispositives emerges. When thinking begins to infringe upon its own conditions, it is possible to bring forth novelties in these problematic fields, thus begetting changes in the normative forms of knowledge, the prevailing power relations and the predefined modes of subjectivation or modes of existence (Deleuze, 1988a: 119–120).

The mere fact that an assemblage belongs to all three realms of reality makes it a part of all of the three powers as which the three planes unfold. This argument finds support in Spinoza’s conception of the participation of finite creatures in divine power (Spinoza, 2018: IVP4D). Jane Bennett (2010: 20–24) adduces Spinoza in a similar way to explain the agency proper to an assemblage. She translates the power possessed by single creatures in Spinoza, which changes according to their variable alliances with other creatures, to the assemblage in Deleuze and Guattari. Deleuze and Guattari, when they shift their focus away from the powers inherent in nature to these powers as possessed by an individual or a brain (with Kant, not Spinoza, being the most important reference), start to speak not of powers, but of faculties. For example, they write that each of the three planes is a ‘cerebral plane’ and that in the case of philosophy, the brain appears as ‘the faculty of concepts’ (Deleuze and Guattari, 1994: 211, 218, see 2, 48, 140; on Deleuze’s interpretation of Kantian faculties as ‘conative powers’ and the analogy with academic faculties, see Lord, 2015: 88–90). In addition to the faculty of conceiving or comprehending, the individual also possesses the other two powers in the form of the faculty of feeling and the faculty of knowing or of applying and fulfilling functions (Deleuze and Guattari, 1994: 212, 214–215). However, the three faculties are initially, and sometimes exclusively, subordinated to a rigorously regulated interaction. For example, Deleuze (1997a: 20) writes in his 1985 book on cinema that we suffer ‘a powerful organization of poverty and oppression’ in everyday life, and this organization shapes our lived experience through simple schemata. ‘We have opinions on everything we perceive or that affects us’, Deleuze and Guattari observe in What is Philosophy? (1994: 155, translation amended), and our individuation already presupposes these opinions with which our lived experience agrees. An individual embodies certain modes of existence, the habits imposed by the regimes of opinion through which life functions, and it thus adjusts itself to the given state of affairs or the prevailing sociopolitical structures. Through the everyday use of the faculties of thinking, through interests, feelings and actions, individuals always assimilate themselves to the all-encompassing order of opinion.

Deleuze and Guattari (1994) write: ‘The brain is the junction – not the unity – of the three planes’ (p. 208, original emphasis). The interfaces and nodes of the multibranched network establish primary brains or, as Deleuze and Guattari call them in ‘From chaos to the brain’, the conclusion of What is Philosophy?, ‘microbrains’ (p. 213). Starting from this assertion, Tony D Sampson (2017: xiv–xvii, 14–17) develops a relational assemblage theory of the brain, which he calls, building on the work of Gabriel Tarde, a monadology of microbrains. Through these microbrains, the outcome of interferences between art, philosophy and science, everything can potentially become brain or subject. The brains that think must not be reduced to organic brains, which will sometimes (as in the case of humans) correlate with primary brains, or to objectified or objectifiable brains, which are defined by science as an adaptable but fragile assembly of billions of neurons connected in a network of countless synapses (Deleuze and Guattari, 1994: 209–210). Thinking is based on the intersections and connections of the three planes where ‘the three aspects under which the brain becomes subject’ are located (p. 210). Thus, the primary brain is the direct subject of three different activities. It is an ‘I feel’ or a ‘soul’ on the plane of composition, an ‘I conceive’ or a ‘mind’ on the plane of consistency and – even if, as a primary brain, it is not an existing entity, that is to say, it does not belong to the realm of the actual or extensive – an ‘I function’ on the plane of reference (pp. 211, 215, original emphases). This primary trilogy is in principle able to transfer its own movements of thought to each of the three planes in such a way that the creative power corresponding to the movements of the plane unfolds through that plane.

The primary brains are to be regarded as a substitute for the centers of indetermination that Bergson cites to explain the genesis of brains (see Malabou, 2008: 33–40). In his 1985 book on cinema, Deleuze (1997a: 211) points out that despite its novelty at the time, Bergson’s conception of the brain still adhered to the traditional model. As Bergson (2005: 30) wrote, the brain ‘adds nothing to what it receives’, resembling ‘a kind of central telephonic exchange’ that has a mediating function but does not produce anything itself. For Bergson, from the outset, the purpose of this center is to delimit an internal world of thought from an external world, and to be occupied by a point of reference that organizes the course of lived experience beyond these boundaries. For Deleuze, the latest neuroscience – knowledge about the function of synapses, electrochemical transmissions and the linking of neurons by synaptic clefts – points with ever-greater clarity to a new model of the brain. This model, firstly, can no longer simply assume an internal world and an external world that are related and mutually compatible. Secondly, it can no longer accommodate the assumption of a center that is passed along predictable connections and associations as stipulated by a given agreement (Deleuze, 1997a: 211). Accordingly, the account of the brain in What is Philosophy? implies a topological space where an absolute inside and an absolute outside come into contact with each other (Deleuze, 1988a: 118–119; see Simondon, 2005: 227–228), and also presupposes a more or less unstable and uncertain network of interfaces and nodes (Deleuze, 1995a: 149; see, for example, Changeux, 1997: 83–90).

Deleuze rejects any system that performs the process of organization by equating and unifying the elements with one another, since, as he wrote in a letter of 1990, ‘the system must not only be in perpetual heterogeneity, it must also be a heterogenesis’ (Deleuze, 2007c: 361, original emphasis). In this sense, the system set out in What is Philosophy? is a system in motion, in which philosophy intersects and connects with art and science (for a discussion of their interferences, see Plotnitsky, 2012; for more historical focus, see Schmidgen, 2015). That is because, firstly, all three forms of thought are involved in the creation that happens in one of them. Even the thought of opinion is based on the interferences between the three planes, since every act of thinking derives from all three faculties while each is tied to a particular plane. In order to create new concepts, the philosopher must separate his or her three faculties from the rigorously regulated interaction in which opinion restricts the three forms to organizing lived experience under the rule of the faculty of knowing. The philosopher needs to generate the intersections or connections that will enable a free interaction. Philosophy, art and science, Deleuze and Guattari (1994: 91) write, ‘are immediately posited or reconstituted in a respective independence, in a division of labor that gives rise to relationships of connection between them’. This division of labor, in which the three forms retain their independence from each other, must be regarded as a free interplay stemming from the originally unregulated use of the cognitive faculties that is, in Kant’s view, the basis of every regulated interaction. Deleuze and Guattari themselves, investigating the plane of consistency, the conceptual persona and the concepts, explicitly cite the free interplay – guided only by taste – between reason, imagination and understanding. As regards the creation of concepts, this means an interaction of philosophy (or the faculty of conceiving) with art (or the faculty of feeling), by means of which philosophy arrives at the perceptions and affections of events formed by concepts, and with science (or the faculty of knowing), by means of which philosophy receives those allusions to actual entities that are contained in events (pp. 2, 77).

Secondly, each of the three forms, with its creation, calls upon the other two to produce correlative creations. ‘Each created element on a plane calls on other heterogeneous elements’, we read in What is Philosophy?, ‘which are still to be created on other planes: thought as heterogenesis’ (p. 199). The creation of novelty, and thus changes in given circumstances and existing entities, never leads to an entirely stable or static equilibrium. The system is kept in constant motion by the correlations between the three divergent forms of thought or creation, and it is always being set in motion anew. The system is not only a moveable system whose mobility equips it to combine the various elements without having to set them into a predefined order. It is, moreover, a system that necessarily moves constantly under its own momentum, also creating and integrating novel elements and continuously modifying or rearranging itself. Unlike Mogens Laerke (2005: 9), who proposes that the system of nature in Deleuze ‘is constantly transforming itself in an immanent dynamics’ but nevertheless regards it as a classical system, I contend that Deleuze, at least in his final book, devises a system that has the crucial properties of a system appropriate for our times.

Along with the interferences between the artistic plane of composition, the philosophical plane of consistency and the scientific plane of reference, every creation brings new bifurcations and produces unstable interfaces and nodes in the multibranched network of planes – ‘culminating points’ where the movements of thought run the risk of either subordinating themselves to the rigorously regulated, stabilizing organization of opinion, or dissolving completely into chaos (Deleuze and Guattari, 1994: 199). The heterogenesis of thought implies that every creative activity takes place in a system involving manifold branchings and transitions between the divergent forms. But every creative activity, even if it encounters a problem that, in different ways, resonates in each of the three forms, remains bound to the plane whose creative power unfolds in solving the problem. Thus, none of these three forms has precedence; each can rise to become an autonomous power only through a division of labor with the other two. Deleuze (2007d) writes that ‘art, science, and philosophy seem to have mobile relations to one another, with each responding to the other, but each with its own specific means’ (p. 302, translation amended).

The Philosopher’s Method

From the system of nature, we can derive a method for the creative activity of the philosopher according to the doctrine of movement upon which the system is based. Unlike the system, the method starts from the individual subject because it must take into account the fact that the philosopher with his or her modes of existence is, just like any other psychosocial type, entangled in the formation of history, itself shaped by the regimes of opinion (Deleuze and Guattari, 1994: 58–59, see 1987: 158–161). The method by which a philosopher may succeed in creating concepts with which to bring forth new events requires a decoupling of the three faculties of thinking from the rigorously regulated interaction that serves the organization of his or her lived experience, and thus allowing the faculties to enter into a free interplay that stokes up momentum until philosophy rears up to unfold an autonomous creative power. The philosopher must liberate the movements of thought from the constraints of opinion, transfer them to the philosophical plane of consistency and convert them into the infinite movements of becoming. The tool for doing so, which the philosopher must invent and animate, is the conceptual persona. A philosopher can only transfer the movements of thought to the plane of consistency by freeing them from ‘their psychological as well as their sociological adhesions’ that have saturated lived experience (Deleuze and Guattari, 1994: 140, translation amended), and by shifting into a conceptual persona that is able to join together the movements of history, which organize the philosopher’s lived experience as an individual subject, with the movements of becoming (pp. 90, 93).

A philosopher emerges from nature, which is always in the process of becoming and at the same time is always and irreversibly changing along with history. Therefore, a philosopher cannot resist the degeneration of thought into opinion by turning to an everlasting and unalterable Being, but only by creating something that is new by its nature – more precisely, a novelty that does not belong directly to history, but still belongs to becoming. To create concepts means to penetrate to the starting points for the development of actual entities, to witness the genesis of individuals at a moment when the components of events and their singular concatenations have not yet evolved into the extensive components of which individuals are comprised and the particular qualities of these individuals (see Deleuze, 1994: 210). This entails going beyond the particular standpoint of personal lived experience because concepts must not be related to that standpoint. Concepts have to be thought, perceived and felt from the point of view of their plane of immanence; they have to be condensed by way of an intuition that accompanies the performance of the infinite movements of becoming by means of the conceptual persona. Alain Badiou regards Deleuze as a comrade in the fight against the conformism imposed on us by prevailing opinions, given the Deleuzian insistence that philosophy’s creative thinking leads through chaos, extends to infinity and entails ‘exposing within us, so far as we can, the human animal to that which exceeds it’ (Badiou, 2009: 118).

In the letter of 1990, Deleuze (2007c: 362) stresses once again that he understands the method of his philosophy as a transcendental empiricism: an empiricism that does not reduce experience to the lived experience of individual subjects, but instead assumes a preindividual and subjectless transcendental field resulting from the movements of thought of the plane of consistency, which cannot be inscribed into a subject of lived experience. For Deleuze, this field itself must be explored and experienced. This very particular kind of experience, which differs fundamentally from ordinary lived experience, is associated with the creative activity of philosophy (Deleuze, 2007c: 362). What is Philosophy? explicitly states that every philosophy depends on an intuition in the Bergsonian sense (Deleuze and Guattari, 1994: 40). According to Deleuze, Bergson’s method of intuition goes beyond the experience, in all its peculiarities, that accompanies the course of ordinary life, to comprise the conditions on which these peculiarities depend. This method seeks the ground of lived experience, or of things and living beings, to reach a concept ‘modeled on the thing itself, which only suits that thing, and which, in this sense, is no broader than what it must account for’ (Deleuze, 1991: 28; see Moulard-Leonard, 2008: 89–103).

The creation of concepts is tied to a specific way of thinking, one that cannot be prescribed by any rigid categories and has no general use. The exercise and experience of creative thinking are made possible by the conceptual persona, which is ‘a living category, a transcendental lived experience’ (Deleuze and Guattari, 1994: 3, translation amended). The ensemble of character traits or features of which the conceptual persona is composed cannot simply be traced back to the use of the thought of opinion. Kant arrives at his categories, universal and unchangeable conditions of possibility of the experience that any subject of lived experience will have, through reflection on the functioning of opinion (Deleuze and Guattari, 1994: 46, 142). In my view, inventing the character traits of the conceptual persona calls for a sort of transcendental deduction, carried out experimentally. Although this deduction certainly has to start from an investigation of the relevant sociopolitical and economic preconditions, it must not degenerate into abstraction and generalization. Deleuze himself paves the way for a deduction of this kind in the ‘Postscript on control societies’ of 1990 (Deleuze, 1995c) and subsequently, through his continued engagement with the thinking of Foucault, by exploring the factors that shape our communication society. The overarching such factor is capitalism, which organizes sociopolitical and economic processes by accelerating and controlling all the movements that are used to adapt or consolidate power structures within society and to subject individuals’ modes of existence to marketing.

Depending on the modes of existence they embody, individuals can be assigned to certain psychosocial types (Deleuze and Guattari, 1994: 68). These psychosocial types belong to history whereas the conceptual personae pertain to becoming; however, they refer to each other and join together. As Deleuze and Guattari (1994) observe, the ‘features of conceptual personae have relationships with the epoch or historical milieu in which they appear that only psychosocial types enable us to assess’ (p. 70; see Ginoux, 1998). Since the historical preconditions change continually, conceptual personae with new traits or features must be invented over and over again. The traits must always correspond to the characteristics of the psychosocial types that enable a sorting of the confusion of movements in the social field. Deleuze and Guattari (1994: 70–73) mention the physical and mental movements of the psychosocial types, their pathological symptoms, their legal status, their relational attitudes and their existential modes, indicating that the conceptual persona necessarily exhibits the corresponding dynamic traits and the corresponding pathic, legal, relational and existential traits. As a living category composed of such traits, the conceptual persona is ultimately nothing other than the manner in which the movements of thought are performed, the will or desire that is inherent to such movements and the dangers that they entail, along with the fundamental orientation of movements of thought, the nature of their relation to the concepts to which they lead, and the mode of existence or insistence that they produce. The conceptual persona as a category for the exercise and experience of creative thinking makes Deleuze’s transcendental empiricism ‘a fully developed method, one of the most fully developed methods in philosophy’, as Deleuze (1991: 13) himself writes of Bergson’s intuition, with ‘strict rules’ that form the basis of the precise operations of philosophy with their convincing and transparent results.

A Sort of Philosophy of Nature

The critical achievement that enabled Deleuze to present a philosophy of nature with his final book is the theory of the three specific planes of philosophy, science and art. When Deleuze announced in 1988 that his next undertaking would be a book entitled What is Philosophy?, he could draw on his earlier treatment of Foucault’s dispositives in the 1980s. This turned out to be a preparatory work which was useful for expanding upon the conception of the assemblage for his philosophy of nature. By contrast, we find, for example, the doctrine of movement had already been elaborated, notably in A Thousand Plateaus, published in 1980. There, with reference to ancient atomism, Deleuze and Guattari (1987) described it as a ‘model… of becoming and heterogeneity, as opposed to the stable, the eternal, the identical, the constant’ (p. 361; see Serres, 2000). Based on the theory of the three planes, in What is Philosophy? they went on to establish their account of the brain, which serves as the pivot between the genesis of an assemblage in the three different realms that are constituted by the three planes and the prescribed functioning as well as the creative possibilities of this assemblage. Through the brain, or more precisely, through the primary brain (with which sometimes an organic brain will correlate), an assemblage can, on the one hand, shape and organize itself, adjust itself to the given opinions and remain more or less stable. On the other hand, an assemblage, through the primary brain with its culmination points, is also most strongly exposed to chance and even chaos and is therefore in principle able to create a novelty in three different ways according to the three forms.

Regarding the theory of the three planes, two characteristics can be stressed to justify the designation of Deleuze’s final book as a philosophy of nature. Firstly, philosophy maintains (besides the interference with art) intersections and correlations with science. In so doing, philosophy neither places itself in opposition to nor above science. In order to put philosophy on a par with science, Bergson develops, as Deleuze observes, a philosophy that correlates with scientific knowledge about the brain. To continue Bergson’s philosophy today means ‘to constitute a metaphysical image of thought that corresponds to the new tracks, channels, leaps and dynamics discovered in the molecular biology of the brain’ (Deleuze, 2007e: 336, translation amended), thus devising a philosophy that matches the new model of the brain as elucidated by the latest knowledge of neuroscience. Along these lines, we find that What is Philosophy? concludes with an account of the brain that in fact corresponds to this new model: ‘Arborized paradigms of the brain give way’, Deleuze and Guattari (1994) state in the conclusion, ‘to rhizomatic figures, acentered systems, networks of finite automatons, chaoid states’ (p. 216, translation amended). However, I would like to emphasize that when philosophy conceives of the brain, it does not grasp the objectified or objectifiable brain of neuroscience as a matter of fact. Furthermore, with its concepts, philosophy neither provides science with a sort of criterion for creating functions nor reflects on the functions created by neuroscience (Deleuze and Guattari, 1994: 161). As Paul Patton (2016: 355–357) points out in relation to the specific ways of creation of philosophy and science in What is Philosophy?, Deleuze and Guattari’s engagement with nature goes beyond the boundaries of a naturalism which implies that there is only the realm of reality which contains no more than the entities that can be constructed by natural science with its scientific method as objects of knowledge.

Secondly, following Spinoza’s conception of an all-embracing nature endowed with powers, and Bergson’s of an infinite, centerless universe that is utterly and always in motion, Deleuze and Guattari assume a nature that, on the basis of three specific planes, generates all things and living beings as assemblages linked to each other. Accordingly, this philosophy of nature does not offer us anything to go on that would allow us to take the discernible distinctions between nature and man, as well as between nature and art or technics, and trace these back to more fundamental differences. ‘Artifice is fully a part of Nature’, Deleuze (1988b: 124) writes with regard to Spinoza’s all-embracing nature, whose order ‘does not make any distinction at all between things that might be called natural and things that might be called artificial’. If artifice refers to human intervention, nature is itself undertaking a process of renewal or modification through such intervention.

Translated by the author in close collaboration with Christopher Shepherd and with contributions from Casey Butterfield and Kate Sturge.