At strategic points in Reading Capital, Louis Althusser introduces Spinoza’s idea of an immanent cause as the decisive concept that is absent from Marx’s discourse.  For the Althusser of 1965, Spinoza’s model of causality is the great missing link in Marx’s thought, a philosophical omission and lacuna of symptomatic force. It explains the whole detour that Marx was forced to take through Hegel’s system of thought. Because Marx was neither aware of the concept of immanent causality in Spinoza nor produced it himself, the idea of the effectivity of structure is found only in practical state in the complexity with which Marx depicts the social reproduction of economic relations in Capital. According to Althusser, however, it appears there in false conceptual clothing, in borrowed language: in Hegelian terms of essence and appearance. This language belongs to a spiritual monism in which all differences are reduced, in a teleological circle, to transitional moments of the self-mediation of spirit.
With unexpected pathos, Althusser describes Spinoza as a marginal figure in the history of philosophy, a misunderstood, ‘repressed’, ‘subterranean’  voice in seventeenth-century metaphysics representing the sole witness not only to Marx’s immense scientific revolution in Capital, but also to Althusser’s own epistemological undertaking of removing from Marx’s philosophy all evolutionist, teleological and humanist elements in order to instigate a repoliticization of Marxism. Althusser finds in the anti-finalism of Spinoza’s philosophy the ‘greatest lesson in heresy that the world has seen’.  His philosophy allows him to conceptually specify Marx’s epistemological break and ascertain in the medium of this rupture how a dialectics that does not carry within itself the promise of its resolution can be linked to the renewal of communist politics in non-Stalinist orientation. Through the rejection of the beginning and the end, through the destruction of the onto-teleological ‘alliance between subject and goal’  and through an epistemology that includes imagination and error in the production of thought, Spinoza serves Althusser as a singular point of reference in order to uncover beneath Marx’s Hegelian terminology the scheme of a complex overand underdetermination of social instances. In a paradoxical temporality that contracts centuries, Althusser finds in Spinoza the ‘only direct ancestor’  of Marx and his attempt to define society as complex structured whole, in which different instances of both base and superstructure interact with one another in their unequal relations and plural temporalities. 
With this forced interpretation, this epistemological act of violence, in which Marx is equipped with a non-Hegelian genealogy and, in an unnoticedly ideal way, reconciled with himself, Althusser stages in the mid-1960s a double overture. First, he introduces Spinoza into structural Marxism, to separate Marx’s economico-critical thought from Hegel’s speculative concept of totality and Feuerbach’s anthropological concept of alienation. He gives structuralism a causality model, in which the genesis of the real is no longer reduced to a mere recursion effect or a ‘combinatory’  of arbitrary elements (phonemes, kinship relations, etc.), but comprises politically significant moments of condensation and displacement. Second, Reading Capital forms the prelude to a wave of Spinoza receptions, in which seventeenth-century metaphysics is shifted far beyond Marxism into the radiant presence of structuralist philosophy. While after Husserl’s Paris lectures on the Meditations and Sartre’s publication of The Transcendence of the Ego, France experienced a phenomenological Descartes revival, Spinoza research remained, until the mid1960s, a largely underdeveloped field.  In the course of a fulminant boost in reception in 1968 and 1969, in almost a single year, the studies of Martial Gueroult, Alexandre Matheron, Gilles Deleuze and Bernard Rousset were published.  Under the influence of Gueroult’s structural-genetic reading, they displayed an unprecedented systematic precision to position Spinoza’s thought against Descartes – particularly, against the doctrine of two substances, the depotentialization of nature, the use of the medieval concept of contingency and the idea of the incomprehensibility of a God of arbitrary decree implicated in the doctrine of the creation of the eternal truths. In comparison Althusser’s reading of Spinoza is characterized by an inverse proportion of philosophical precision and the strategic positioning of Spinoza in Marxism. Although Althusser located the political effectivity of Marx’s philosophy in the theoretical struggle over the concept of immanent causality, the specifications of this concept remain a site of fracture in his thought, marked by unstable and changing terminology. In the sense of a symptomatic reading, it is precisely here that the pivotal problem that moves Althusser’s thought is found, without it being possible for him to pose it unequivocally.
In other words, the changing determinations of immanent causality are the symptom of Althusser’s Marxism. In searching for the seam that links, through their distance, philosophy and class struggle, Althusser did not stop ‘thinking differently’  the question of causality in a self-deconstructive manner, which is rare in its severity. Considering that the leitmotif of symptomatic reading says that thought ‘only progresses, i.e., lives, by the extreme attention it pays to the points where it is theoretically fragile’, thus by posing the unknown ‘in the rigour of a problem’,  I will trace Althusser’s unwillingness regarding the question of immanent causality to decide between Spinozist and Hegelian concepts, between vague references to Lacan’s causality of the impossible and a structural-genetic scheme of immanent causality as developed differently in Gueroult and Deleuze’s reading of Spinoza. Under a certain influence of Badiou, Althusser, in his late ‘materialism of the encounter’, even tends to the idea of a constitutive void understood in the sense of a ‘transcendental contingency’,  according to which an event transcends the conditions of its situation, because ‘no law presides over [it]’.13
In the following remarks on immanent causality, I will read Althusser with Deleuze by considering the time span between the publication of Reading Capital in 1965, Althusser’s lecture ‘Marx’s relation to Hegel’ presented in Hyppolite’s Seminar in February 1968, and the appearance of Deleuze’s Study on Spinoza – entitled Expressionism in Philosophy – later that year. Via the detour of Deleuze, I will try to detect the concepts that are missing in Althusser’s reading of Spinoza – positive determination, difference without negation, heterogenesis – in order to consider the consequences that these lacunae have for Althusser’s project to repoliticize Marxism. Deleuze assumes here the function Spinoza assumed in Althusser: he is an operator to uncover missing concepts and question what seems to be most evident – in this case Althusser’s anti-Hegelianism.
Althusser as reader of spinoza
Althusser’s habilitation defence from 1975, ‘Is it Simple to be a Marxist in Philosophy?’, shows how Spinoza is at the centre of Althusser’s concerns in three respects.  First, in a philosophical respect, the world or the production of the real have no historical or anthropological goal in Spinoza. All ends are regional, provisional and decentred in their sense. The impersonal process of infinite transindividuation does not coincide with social production. Both the extimity and the immanence of finite modes in substance designate the objectivity of an impersonal genesis, in which individuals produce changing goals, which are never the goal of the impersonal process itself.  The reconciliation and identity of naturalism and humanism, of which the young Marx speaks at the end of the Paris Manuscripts,  is impossible in Spinoza. Therefore, secondly, in an epistemological respect, the production of the true in Spinoza operates without any external truth criterion through the imaginations and the affects. Inadequate ideas do not represent mere errors, but signs of both the natural and social conditionality of perceptual faculties that serve as the initially given, though unstable resources of the production of thought. Unlike in Descartes, an inadequate idea is no negativum that attests to the impotentiality of someone participating in the nothingness of error, but the reverse. The conditions for the production of common notions are implicated and enveloped in all the distorted, imagined and erroneous ideas that individuals produce of the natural and historical relations of contingency and violence, into which they are thrown, without being able to intellectually master them in any immediate way. As Althusser never tires of quoting: ‘Verum index sui et falsi. What is true is the sign both of itself and of what is false.’  Corresponding to this performative concept of truth is, thirdly, the ideology-theoretical idea – in an inversion of the position presented in the Communist Manifesto – that the ‘ideas of [the] ruling class’  aren’t the dominant ideas of each age that obscure its reality. Instead one has to grasp the ‘imaginary of the dominated’  as constitutive signs that generate reality in a real–imaginary manner. The imagination is understood as the critical site, where individuals renegotiate the relationships they have established to the contradictory conditions of their existence.
This materialism of the imaginary opened [for Spinoza] a way to a surprising conception of the First Level of Knowledge: not at all, in fact, as a ‘piece of knowledge’, but as the material world of men as they live it, that of their concrete historical existence. 
Since in Spinoza one liberates oneself without teleological guaranty, the leap into thought and the work of emancipation have to be continuously repeated. The imaginary identifications and the conflicts will never disappear; they are, as Althusser has said, of eternal quality. This implied for him rejection of the ‘myth of a community of labouring men’  or of any society without distance, nonsense and real oppositions which would correspond to ‘a mode of production without relations of production’.  Hence, in Spinoza, the idea that humankind comes to itself in the historicity of its own praxis making politics end in the transindividual nexus of humanity’s all-sided activities is deconstructed in the same way as it is prohibited to purify politics to a mere, aneconomic break. If there is something that links different strands in contemporary radical thought, then the opposite tendency, in re-ontologizing politics, to subsume politics under single philosophemes – like fidelity to the event, disagreement, potentiality of the not, etc. Though these philosophemes are all post-metaphysical ones which do not have recourse to fixed qualities or predicates, they all seem to be conceptualized in a way that excepts them from critique and corruption. They might be rare, and they might exhaust, but they do not revert or differ in themselves.
How does Althusser conceive immanent causality in Spinoza? What happens in his view in the process of an immanent determination? In Reading Capital Althusser basically gives the same answer as in For Marx, only now it is not oriented to the problem of the political break (condensation, displacement or fusion of contradictions, dislocation of their internal aspects), but to that of the reproduction of social formations. He states that the social reproduction process has to be conceived through the mechanism by which social elements in their degrees of effectivity are displaced on the basis of their positions in the structure. With this topological model, Althusser particularly wants to remove Hegel’s model of causality from Marxism. Relatively schematically, he attempts to replace what he calls the expressive model of causality in a tradition stretching from Leibniz to Hegel, in which the whole is conceived as harbouring an inner principle articulated by ‘phenomenal forms of expression’.  That is why, already in ‘Contradiction and Overdetermination’, Althusser explained that Hegel’s ‘complexity of a cumulative internalization’ of all forms of determination, in which the real is reduced to the self-manifestation of a simple principle, must be replaced by the ‘complexity of an effective overdetermination’.  He ascribed the proximity between Spinoza and Marx to the rejection of a spiritual monism, in which the complexity of social structures and the plurality of their times had been suppressed. In Reading Capital, Althusser therefore draws on Spinoza’s idea that the production of the real can dispense with teleology because its principle of affirmation of difference does not lead to the resolved relation of totality and infinity, but a non-totalizable plurality of provisional results, which are continuously reopened to differentiation and reactualization. With the hypothesis that the structure expresses itself in the displacement of degrees of effectivity between relatively autonomous elements, Althusser takes up Marx and Engels’s idea of a totality of social relations that reaches far beyond the economic, and consists in the interaction of really distinguished elements, which are only determined ‘in the last instance’, through the realization of surplus value. So as not to withdraw to a relativist position of infinitely mutating interactions, Althusser claims it would be necessary to pose a primacy of determination by the economic that unifies the play of differences between social elements by determining the displacements of their degrees of effectivity.  How is this to be understood?
In Althusser the economic relations that are reducible neither to an anthropological substance nor to a ‘universal matrix’  of intersubjectivity (struggle for recognition, master–slave relationship, etc.) build a framework in which they are framed themselves. As simultaneously both element and frame, the economic relations determine the degree of effectivity or the indices of reflection with which the social instances, to which they belong and constantly have to be added, act on each other and allow other contradictions or other aspects in a contradiction to become dominant. Correspondingly, in a redetermination loop the superstructures determine the economic relations, whose conditions of existence they represent. This is why the determining relationships are situated on the same level as the instances which they determine. The economic relationships are reflexively included in the elements they determine, and must be understood as ‘determining, but also determined in one and the same movement’ – in a word, as ‘overdetermined’.  Lacan once summarized this reflexive ungrounding of a ground in the formula ‘I have three brothers, Paul, Ernest and me.’  In this context, it is decisive for Althusser to clarify the position of the economic structure in the overall structure. The task is to ‘reveal the site occupied in the structure of the whole by the region of the economic, therefore to reveal the articulation of th[e] [economic] region with other regions (legal-political and ideologial superstructure) and the degree of presence (or effectivity) of the other regions in the economic region itself’. 
For this reason, Althusser emphasized that when Marx replaced Ricardo’s concept of profit with that of surplus value, he did not simply substitute a word, but created an entirely new problem. To the criticism already advanced by Conrad Schmidt, an economist and contemporary of Marx, that surplus-value is a ‘theoretical fiction’, since it represents a non-operational, non-calculable and non-quantifiable entity, Althusser responded that ‘Marx accepts and uses measurement – for the “developed forms” of surplus-value (profit, rent and interest). If surplus-value is not measurable, that is precisely because it is the concept of its forms, which are measurable.’  Beyond substanceor form-logical interpretations, the law of value is here understood as a concept that designates the social ‘conditions and limits’,  under which quantitative forms of surplus value are operationalized as homogenous and measurable. It designates ‘the limits of … variation’  of these equivalences. It determines the variability of the interval, in which surplus-value can be realized as profit in so far as an immense complexity of heterogeneous practices are mediated against one another. The concept of surplus value determines the variability of the mechanisms in which different economic processes, heterogeneous circuits of fixed and circulating capital, the plural times of the overall reproduction of capital are sutured with an enormous multiplicity of social relations, in which they exist and through which they are redetermined. In a few words, the concept of surplus-value is ‘the field of its [own] inadequacy’.  The economic stops being a bearer of essentialism and necessity, and the contradictions of the capitalist society formation cease to contain within themselves the promise of their own resolution and do not converge with a foreseeable end, but must be conceived through the composition and decomposition of social conflicts, in combined – class and non-class – articulations.
Hindess and Hirst as well as Laclau and Mouffe have levelled the criticism that Althusser, with the primacy of economic determination, ruined the complexity of social antagonims.  They argue that with the distinction between economic contradictions and their non-economical conditions of existence Althusser reconverted the superstructures into an ‘internal moment of the economy’,  where they had no other role to serve than the reflection of the economic mechanisms of effectivity. Laclau and Mouffe therefore separated the schema of overdetermination from the economic determination primacy. But how did they conceptualizse the causality of what they called the ‘ensemble of totalizing effects in an open relational complex’?  As pinpointed by Žižek in the late 1980s, Laclau and Mouffe increased the clandestine Hegelianism present in the concept of structural causality by grounding society in that which society had to exclude to construct its inner coherence and sense.  Hence the void, the limit or the impossible become constitutive elements of politics. As Ceren Özselçuk, among others, has noted, the reverse conclusion seems to be more productive: the Althusserian model of immanent causality helps to resist the tendency in contemporary radical philosophy to understand economy as a structural field of stability, to which is opposed the field of overdetermination and event, ideally separating what is bound and what is unbound, what is statist and what is moving, what is functional and what is political. 
What is still hegelian?
‘What is still Hegelian in that which allows us to think against Hegel?’, Foucault asked.  Is Althusser’s model of structural causality really ‘Spinozist’? Is Spinoza really Althusser’s ‘sole witness’ in the attempt to free materialism from evolutionist, anthropological and teleological perspectives in order to develop the model of a complex whole without closure, ‘which is only the active relation between its parts’?  Only three years after the publication of Reading Capital Althusser returned to this question in a lecture presented in Jean Hyppolite’s seminar and later published under the title ‘Marx’s Relation to Hegel’. A striking change in perspective has taken place. At issue is no longer to separate Marx from Hegel via a detour through Spinoza, but to separate Hegel from himself, to create a different or second Hegel, a ‘Hegel beyond Hegel’.  Since the publication of ‘Contradiction and Overdetermination’ in 1962 Althusser’s critique of Hegel focused on the homogeneity and simplicity of the model of dialectic, a simplicity, as Warren Montag added, ‘that can be demonstrated despite and against the appearance of an ever-increasing and thus cumulative complexity that accompanies its movement towards the end in which it is fulfilled and completed’.  By turning to the Science of Logic as read by Lenin, Althusser attempts to separate Hegel from the ‘complexity of a cumulative internalization’  to which he himself had reduced him. The identification of being and nothingness at the beginning of the Logic – constantly criticized by Althusser for introducing a genetic totality that creates its own matter – now takes on a paradoxical role in the genesis of materialist philosophy. The importance of Hyppolite’s reading of Hegel here should not be underestimated.
Like Deleuze, Althusser finds in Hyppolite’s Logic and Existence a refined, non-anthropological interpretation of Hegel that is directed against Kojève’s reading of the Phenomenology of Spirit. Drawing on the last chapter of Logic and Existence, Althusser stresses that the young Marx destroyed Hegel’s radicalism when he projected Feuerbach’s anthropology into the Phenomenology of Spirit, making from each objectification an alienation, from each alienation a human alienation, and from the whole history of the alienation of the spirit the history of the alienation of the human subject: ‘Now, as M. Hyppolite has very well noted, nothing is more foreign to Hegel’s thought’, Althusser writes, ‘than this anthropological conception of history.’  By equating being and nonbeing at the beginning of the Logic, Hegel, according to Althusser, turns out to be a radical thinker of immanence, who suspends the beginning in the beginning itself, in so far as he sees the immediate positivity of any first something as being already mediated. On the basis of its own indetermination, its lacking of any determinate predicates, any first something is transformed, as soon as we want to get hold of it, into its own other, nothingness. By equating being and non-being, Hegel hence declares that everything has always already begun, and the continuity of the process consists in its discontinuity and extension. That is why Hegel presents the infinite or absolute in no determined figure. There will be other figures, as Nancy said, ‘successive forms in passage, forms of passage itself’.  That Hegel rejects the origin as a ‘philosophical issuing bank’  transforms his thought, according to Althusser, in a theoretical premiss of materialism: it destroys the category of beginning and eliminates every idea of the subject as interiority or personality. On the other hand, Hegel obviously created new ways of thinking delegations of the origin and of the subject – namely ‘the process itself in its teleology’.  Through the mechanisms of sublation and negation of the negation he projects the origin into a goal, which retroactively posits its own beginning. With reference to Derrida’s (i.e. Heidegger’s) idea of a crossing-out, a rature, whereby a metaphysical category ‘is effaced while still remaining legible’,  Althusser shows how Hegel reintroduces the origin by way of the reflexivity of the process. What we find in the Logic, Althusser writes, is ‘the theory of the non-primordial nature of the origin’.  Nevertheless, Althusser pinpoints in the Logic resources to overcome the teleological conception of the dialectic, and to leave the circle of sublation, in which the superseded is preserved ‘asthe-internalized-transcended’.  Thus, he begins ‘the arduous task’  of rehabilitating Hegel. Now, Marx is not only close to Hegel due to what the latter inherited from Spinoza, but also due to owing his most crucial philosophical category to him: ‘the concept of a process without subject’.  This is not to forget that the return to Spinoza, as Althusser starts to claim, comes at a certain price – ‘[f]or the adventure is perilous, and whatever you do, you cannot find in Spinoza what Hegel gave to Marx: contradiction.’53 As Hyppolite indicated in the American preface to Studies on Marx and Hegel, in the doctrine on Essence, in the passages of the Logic in which Hegel is most unfaithful to his monism, Althusser comes across an idea of structures that fits his model of structural causality. Hegel ‘describes here structures’, Hyppolite writes, ‘in which the essential and unessential are reflected in one another, in which the existential conditions of a dominant contradiction are an element in the contradiction itself’.  As Lenin stated in his philosophical notebooks, to each moment of a situation is given weight, each drop in a river is considered, regarding its position, its movement, its speed, its relation to all other drops. Hyppolite was not the first to point out to Althusser that on this path it is not possible to unequivocally separate Marx’s from Hegel’s idea of determination by attributing to one ‘the complexity of an effective overdetermination’, and to the other ‘the complexity of a cumulative internalization’.  On a number of occasions, Warren Montag has drawn attention to a correspondence from 1965 in which Macherey, a couple of years earlier than Hyppolite, sets out for Althusser how far Spinoza’s model of immanent causality is characterized above all by the idea of inner differentiation. With reference to the doctrine of attributes, the idea of the differential composition of matter, and to Deleuze’s Lucretius commentary, Macherey declares that the immanent expression of the infinite that traverses the finite cannot be grasped in Spinoza in the metonymic effects of a complex structured whole.
The doctrine of attributes
While Althusser simplifies the problem of causality through polar schematization – mechanist vs structural, expressive vs immanent causalities, etc. – Deleuze, in a reverse operation in Expressionism in Philosophy, makes it more complex by showing how Spinoza integrated into his ontology Neoplatonist, scholastic and Renaissance philosophical elements. In a sort of secret history of the philosophy of immanence, Deleuze reconstructs how Spinoza ‘grafted an expressive immanence of Being onto the emanative transcendence of the One’.  He starts by arguing that Plotinus’ emanative and Spinoza’s immanent cause both remain in themselves. The emanative cause, however, stands over being, and its effects leave a cause that remains in itself. The effects are nothing but the things that follow, the descending things, manifesting the degradations of a being that flows out of and down from an eminent One. For Deleuze, Spinoza’s radicalism lies in the hypothesis that the effects remain in the cause, just as the cause remains in itself:
From this point of view the distinction of essence between cause and effect can in no way be understood as a degradation. [It] does not exclude, but rather implies, an equality of being; it is the same being that remains in itself in the cause, and in which the effect remains as in another thing. 
For Deleuze, due to the equality and univocity of being, immanence is not to be separated from the idea of expression: the substance expresses itself in its effects, while on a second level the effects express themselves in the substance as dissimilar modifications. This second level is that of ‘the very production of particular things’,  of matter, psyche and thought, which Althusser does not discuss in his reading of Spinoza, a reading which, as André Tosel points out, removes from Spinoza not only ‘every ethical-political dimension’,  but some of its core metaphysical inventions.
Althusser misses two fundamental characteristics of Spinoza’s model of causality: first, that determination is affirmative and positive; second, the cause is not absent but explicated through its effects in a non-representative, non-resembling expression. Althusser conceives the activity of the immanent cause only through the displacements of the ‘ind[ices] of effectivity’ which are determined by the positions that social relations occupy ‘in the general structure of the whole’.  However, in Spinoza, expression primarily has nothing to do with the retroactive reflexivity between the parts of a whole, but with the correlation of intensive potentialities and extensive parts articulating a certain degree of nature’s infinite impersonal power between minimal and maximal thresholds. While for Deleuze it is the individuation of such a degree that takes place in the distances internal to the structure, Althusser restricts himself to saying that variation, dislocation and condensation take place in this distance, without analysing the type of activity characteristic for the individuation of a relation. Deleuze holds that Spinoza’s philosophy of expression rejects Hegel’s basic alternative: either ‘the indeterminate, the indifferent, the undifferentiated or a difference already determined as negation, implying and enveloping the negative’.  As against Hegel’s idea that each determination is a negation, Deleuze refers to Spinoza in order to think determination as affirmation, or, in Spinoza’s own words, ‘[t]hat by which things are said to be conditioned to act in a particular manner is necessarily something positive’.  The following theses are therefore linked: the cause affirms itself in its modifications; the modifications express intensive degrees of the cause; the indeterminate is not an indifferent abyss, but the internal differentiation of the cause itself. Here, everything depends on thinking difference not as distinction, but as that by which distinction makes itself by ‘differencing’ differential relations. Spinoza invents a couple of limit concepts to think this expressionism. There is only space to sketch briefly one of them here, before concluding with some remarks about how the thought of politics is affected by those limit concepts.
Drawing on Gueroult’s objective interpretation of the attributes, Deleuze clarifies a problem that has been noted by many readers of the Ethics: the impersonal principle of God at the beginning of the book is structured around a spectacular contradiction regarding the substance–attribute relation. Defining substance as something that is in-itself and conceived-through-itself,  Spinoza develops in the first eight propositions of the Ethics the idea of an infinite plurality of attributive substances or, as he says, of ‘substances of one attribute’, substantiae unius attributi.64 They are all in-themselves, and conceived through-themselves. They express essential determinations of being, of which we are only aware of two: thought and extension. If, however, one starts from the sixth definition of the Ethics, in which God is introduced as an ‘absolutely infinite [being]’ that ‘consist[s] in infinite attributes’,  one is led to the idea of a single substance for all attributes. From an analytic operation, distinguishing constitutive differences in substance, Spinoza proceeds to a synthetic operation in which all attributes are integrated into a single substance. From the differentiality of the infinite – the plurality of infinitely many substances of only one attribute – Spinoza advances to a disjunctive synthesis, in which one substance comprises all attributes without totalizing them, since substance is not their sum, it is not their third. As this transition is difficult to understand, many readers conceived the idea of infinite attributive substances – introducing Spinoza not as thinker of the One, but of original differentiality – as hypothetical and as invalidated as soon as one reaches definition six of the unity of a single substance. The speculative primacy of differentiality would then be empty or void. Other readers – notably Hegel – resorted to the fourth definition of the Ethics, in which the attribute is determined as ‘that which the intellect perceives as constituting the essence of substance’.  Hence, the attributes are conceived as something dependent on an intellect that reflects being in external forms. The attribute transforms into an element related to something existing outside of substance. This made Hegel claim that substance is an indeterminate abyss. As soon as something appears in it, it is externalized through an intellect that grasps it from outside, so that being is gradually dispersed in its manifold externalizations, until it increasingly ‘obscures itself and night, the negative, is the final term of the series, which does not first return into the primal light’. 
As Deleuze points out, however, the infinite for Spinoza is a plane of differentiation. Thus, ‘in all rigor, one as a number is no more adequate to substance than 2, 3, 4 … are adequate to attributes as qualified sustances’.  If the first eight propositions of the Ethics are ‘perfectly categorical’,  this is because they introduce into a theory of immanent differentiation, in which the attributes are not negatively distinguished from one another like x from y, or one countable thing from the next. The attributes constitute an irreducible heterogeneity of multiplicities that are differential in themselves. That is, in the doctrine of attributes Spinoza develops the idea of positive determination that represents the pivotal speculative principle of his philosophy in which determination is not conceptualized through negation, but through non-resembling expressions differentiating what is already differential in itself. Ontologically one, formally diverse: the attributes are not parts of the substance, which are distinguished among themselves through concrete negation, but represent ‘constitutive’, ‘structural’ and ‘differential elements’  which are only formally distinguished in the substance. With recourse to Duns Scotus’s idea of a distinctio formalis,  Deleuze finds in Spinoza the model of ‘a purely affirmative difference without negation’  in which the attributes are undetermined without being undifferentiated. They are the differential itself, differences in potentiality, which are expressed, articulated and embodied. According to Deleuze, the doctrine of attributes therefore challenges us to think differentiation ‘free from opposition and privation’ as well as self-affirmation ‘free from eminence and analogy’,  in which the distinguished sides retain their positivity, because they are not determined by reciprocal oppositions, but by their inner modulation. They are operators of heterogenesis.
To conclude: my hypothesis is partisan. By renouncing the idea anchored in negative theology that the One is absent and inscribes itself as difference of this absence in the structure of being (as self-split of the One), Spinoza does not only invent a new mode of thinking difference as inner differentiation or difference in itself, but by this metaphysical invention he also produces a new mode of thinking politics through the inner differences of its acts. Politics thus requires us to comprehend what lies at the limit of the (un)thinkable – the critical thresholds in the transformations of mass potentialities where a certain increase in potentiality induces a leap into thought, while a certain decrease catalyses resentment and fear of difference. These passages between passive and active affects, between the potentialization and depotentialization of psychic life, are always passages in potentiality itself. On the one hand, politics in Spinoza, as transindividual production of thought, as passage from inadequate ideas and imaginary stereotypes to the joys of thinking and the affirmation of difference, manifests the capacities of the multitude for leading a life of non-domination which is founded neither in voluntary decisions nor in subjective acts of the intellect, but in transindividual relations and transferences between infinitely variable fields of matter, psyche and thought. On the other hand, however, these physical and psychic passages from the imaginary to the intelligible are for Spinoza always provisional and partial. This is why his political thought is minimally confident, based on the vitalist assumption that the forces of life are excessive, thus can partially change from imaginary identifications to adequate ideas and insitute this change, give it rigour and duration. At the same time his thought is maximally realistic and critical, since it registers the extent to which the forces of life are invested in the political-theological apparatuses of domination. This is why Spinoza breaks with any aneconomic or exceptionalist ideas of politics as that which is other than being, or which by definition rules out any determinate objects and laws.
The absolute democracy of which he speaks is based on the indeterminate or virtual ground of the affects and forces of life that cannot be represented in the figure of a people, a party, or any other collective subject. It can only be constituted and reconstituted through the deconstruction of the imaginary selfrepresentations of the multitude – that is, through self-critique. But this self-critique has to be part and parcel of a transindividual process in which it experiences its own genetic force; if not, it will be reduced to an ascesis or obligation, and thus tend to decompose. That is, centuries before Nietzsche and Foucault, Spinoza thinks that the forces that pass through the individuals are catalysers both of liberation and of oppression. And politics is understood as an experiment in interrupting, in the very process of liberation, the re-emergence of the fear of difference and its destructive and oppressive forces. The production of society through affects spans a field that knows both a vector of potentialization or intellectualization and the becoming reactionary of the multitude. To think and to make politics is to relate these processes to one another and to change their relationship.
Translated by benjamin carternotes
1. ^ See Louis Althusser, Étienne Balibar, Roger Establet, Jacques Rancière and Pierre Macherey, Reading Capital. The Complete Edition, trans. Ben Brewster and David Fernbach, Verso, London and New York, 2016, pp. 28–9.
2. ^ Ibid., p. 250. 3. Louis Althusser, ‘Elements of Self-Criticism’, in Essays in Self-Criticism, trans. Grahame Lock, NLB, London, 1976, p. 132.
4. ^ Ibid., p. 137. 5. Althusser et.al., Reading Capital, p. 250. 6. See ibid., pp. 252–8.
7. ^ Ibid., p. 7. See additionally Althusser, ‘Elements of SelfCriticism’, p. 129.
8. ^ After the publication of the works of Brunschvicg and Delbos, Rivaud and Alain at the beginning of the twentieth century, except for Darbon’s Études spinozistes (1946) almost no further books appeared on Spinoza. The study of Sylvain Zac’s books of the early 1960s, L’idée de vie dans la philosophie de Spinoza and Spinoza et l’interprétation de l’écriture, was restricted to Spinoza scholars. Only the lectures of Ferdinand Alquié, Nature et verité dans la philosophie de Spinoza and Servitude et liberté selon Spinoza, received considerable attention. See Pierre Macherey, ‘Spinoza 1968: Gueroult ou/et Deleuze’, in Patrice Maniglier, ed., Le moment philosophique des années 1960 en France, PUF, Paris, 2011, pp. 291–313.
9. ^ See Gilles Deleuze, Expressionism in Philosophy: Spinoza, trans. Martin Joughin, Zone Books, New York, 1990; Martial Gueroult, Spinoza I. Dieu (Éthique I), Georg Olms, Hildesheim and New York, 1968; Bernard Rousset, La perspective finale de l’Éthique et le problème de la cohérence du spinozisme. L’autonomie comme salut, Vrin, Paris, 1968; Alexandre Matheron, Individu et communauté chez Spinoza, Éditions de Minuit, Paris, 1969.
10. ^ Louis Althusser, ‘Der Anspruch, anders zu denken’, in Der Materialismus der Begegnung, trans. Franziska Schottmann, diaphanes, Berlin, 2010, p. 19. This paragraph is included neither in the Écrits philosophiques et politiques nor in Philosophy of the Encounter. It directly precedes the chapters that have been edited under the title ‘The Underground Current of the Materialism of the Encounter’.
11. ^ Althusser et al., Reading Capital, p. 29. 12. Louis Althusser, ‘The Underground Current of the Materialism of the Encounter’, in Philosophy of the Encounter: Later Writings, 1978–1987, ed. François Matheron and Oliver Corpet, trans. G.M. Goshgarian, Verso, London and New York, 2006. p. 170.
13. ^ Ibid., p. 194. 14. See Louis Althusser, ‘Is it Simple to Be a Marxist in Philosophy?’ in Essays in Self-Criticism, pp. 163–207.
15. ^ See André Tosel, Du matérialisme de Spinoza, Éditions Kimé, Paris, 1994, p. 35.
16. ^ See Karl Marx, ‘The Economic and Philosophical Manuscripts’, in Early Writings, trans. Gregor Benton and Rodney Livingstone, Penguin, Harmondsworth, 1992, p. 536: ‘This Communism, as ful y developed naturalism, equals humanism, and as ful y developed humanism equals naturalism; it is the genuine resolution of the conflict between man and nature, and between man and man, the true resolution of the conflict between existence and being, between objectification and self-affirmation…’
17. ^ Althusser, ‘Elements of Self-Criticism’, p. 122. 18. Karl Marx and Friedrich Engels, The Communist Manifesto, trans. Samuel Moore, Penguin, London, 2002, p. 86: ‘What else does the history of ideas prove, than that intellectual production changes its character in proportion as material production is changed? The ruling ideas of each age have ever been the ideas of its ruling class.’
19. ^ Étienne Balibar, ‘The Non-Contemporaneity of Althusser’, in E. Ann Kaplan and Michael Sprinker, eds, The Althusserian Legacy, Verso, London and New York, 1993, p. 13.
20. ^ Althusser, ‘Elements of Self-Criticism’, p. 136. 21. Louis Althusser, ‘Marx in his Limits’, in Philosophy of the Encounter, p. 36.
22. ^ Ibid., p. 37. 23. Althusser et al., Reading Capital, p. 342. 24. Louis Althusser, ‘Contradiction and Overdetermination’, in For Marx, trans. Ben Brewster, Penguin, Harmondsworth, 1969, p. 101.
25. ^ See Althusser, ‘Is it Simple to Be a Marxist in Philosophy?’, p. 183.
26. ^ Althusser et al., Reading Capital, p. 328. 27. Althusser, ‘Contradiction and Overdetermination’, p. 101. 28. Jacques Lacan, The Four Fundamental Concepts of PsychoAnalysis, trans. Alan Sheridan, Hogarth Press, London, 1977, p. 20.
29. ^ Althusser et al., Reading Capital, p. 334. 30. Ibid., p. 313. 31. Ibid., p. 314. 32. Ibid., p. 227. 33. Ibid., p. 227. 34. See, for example, Antony Cutler, Barry Hindess, Paul Hirst and Athar Hussein, Marx’s ‘Capital’ and Capitalism Today, Routledge, London, 1977, pp. 167–328.
35. ^ Ernesto Laclau and Chantal Mouffe, Hegemony and Socialist Strategy: Towards a Radical Democratic Politics, Verso, London and New York, 1985, p. 98.
36. ^ Ibid., p. 103. 37. See Slavoj Žižek, ‘Beyond Discourse-Analysis’, in Ernesto Laclau, ed., New Reflections on the Revolution of Our Time, Verso, London and New York, 1990, pp. 249–60.
38. ^ See Ceren Özselçuk, ‘Louis Althusser and the Concept of Economy’, in Katja Diefenbach, Sara R. Farris, Gal Kirn and Peter D. Thomas, Encountering Althusser: Politics and Materialism in Contemporary Radical Thought, Bloomsbury, London and New York, 2013, pp. 207–9.
39. ^ Michel Foucault, ‘The Order of Discourse’, in Robert J.C. Young, ed., Untying the Text: A Post-Structuralist Reader, Routledge, London and Boston MA, 1981, p. 74.
40. ^ Althusser, ‘Elements of Self-Criticism’, p. 141. 41. Warren Montag, ‘Hegel, sive Spinoza: Hegel as His Own True Other’, in Hasana Sharp and Jason E. Smith, eds, Between Hegel and Spinoza: A Volume of Critical Essays, Bloomsbury, London and New York, 2012, p. 87.
42. ^ Montag, ‘Hegel, sive Spinoza’, p. 86. 43. Althusser, ‘Contradiction and Overdetermination’, p. 101. 44. Althusser, ‘Marx’s Relation to Hegel’, p. 182
45. ^ Jean-Luc Nancy, The Restlessness of the Negative, trans. Jason Smith and Steven Miller, University of Minnesota Press, Minneapolis, p. 8.
46. ^ Althusser, ‘Is it Simple to Be a Marxist in Philosophy’, p. 179. 47. Louis Althusser, ‘Marx’s Relation to Hegel’, in Politics and History: Montesquieu, Rousseau, Hegel, and Marx, trans. Ben Brewster, NLB, London, 1972, p. 183.
48. ^ Jacques Derrida, Of Grammatology, trans. Gayatri Chakravorty Spivak, Johns Hopkins University Press, Baltimore MD, 1997, p. 23.
49. ^ Althusser, ‘Marx’s Relation to Hegel’, p. 184. 50. Ibid., p. 181. 51. Montag, ‘Hegel, sive Spinoza’, p. 84. 52. Althusser, ‘Marx’s Relation to Hegel’, p. 182. 53. Althusser, ‘Elements of Self-Criticism’, p. 140. 54. Jean Hyppolite, Studies on Marx and Hegel, trans. John O’Neil , Harper & Row, New York 1973, p. ix.
55. ^ Althusser, ‘Contradiction and Overdetermination’, p. 101. 56. Deleuze, Expressionism in Philosophy: Spinoza, p. 176. 57. Ibid., p. 172. 58. Ibid., p. 14. 59. Tosel, Du matérialisme de Spinoza, p. 209. 60. Althusser et al., Reading Capital, p. 254. 61. Gilles Deleuze, Difference and Repetition, trans. Paul Patton, Continuum, London and New York, 2001, p. 52.
62. ^ Baruch de Spinoza, The Ethics, trans. R.H.M. Elwes, in EthicaDB. Digital and multilingual publication of Spinoza’s Ethics, E1p26d: www.ethicadb.org/plan.php?lanid=3 [archive]&lg=en&ftop=82px (10/2/2016) (hereafter abbreviated E, part, proposition, etc.)
63. ^ See E1def 3: ‘By substance, I mean that which is in itself, and is conceived through itself; in other words, that of which a conception can be formed independently of any other conception.’
64. ^ E1p8 and d: ‘Every substance is necessarily infinite. Demonstration: There can be only one substance with an identical attribute … [substantia unius attributi]; its nature, therefore, involves existence …’ For the concept of a substance constituted by only one attribute, see Gueroult, Spinoza I, pp. 51–5.
65. ^ E1def 6: ‘By God, I mean a being absolutely infinite – that is, a substance consisting in infinite attributes, of which each expresses eternal and infinite essentiality.’
66. ^ E1def4: ‘By attribute, I mean that which the intel ect perceives as constituting the essence of substance.’
67. ^ Georg Friedrich Wilhelm Hegel, The Science of Logic, trans. A.V. Miller, George Al en & Unwin, London, 1969, § 1184, www.marxists.org/reference/archive/hegel/works/hl/hl530.htm [archive] (accessed 10 February 2016).
68. ^ Gilles Deleuze, ‘Gueroult’s General Method for Spinoza’, in Desert Islands and Other Texts, 1953–1974, Semiotexte, New York, 2004, p. 150. See additional y Gueroult, Spinoza I, pp. 148, 156–60, 500–528.
69. ^ Deleuze, ‘Gueroult’s General Method for Spinoza’, p. 149. 70. Ibid., p. 50. 71. For the hypothesis of a Scotist inspiration of Spinoza through the recourse to the concept of formal distinction, see Deleuze, Expressionism in Philosophy: Spinoza, pp.. 62–7.
72. ^ Deleuze, ‘Gueroult’s General Method for Spinoza’, p. 150. 73. Deleuze, Expressionism in Philosophy: Spinoza, p. 60.