I.i. What is the problem of heterogeneity?

The ‘problem of heterogeneity’ is introduced by Schaffer (Reference Schaffer2010a). As he himself recognizes, this is a new name for a very old problem, one that has accompanied monism since its invention, and is probably better known as the problem of the one and the many.Footnote ¹

As Schaffer reconstructs it, the problem arises from ‘the very general sort of empirical information […] that the world is heterogenous, in the sense of featuring qualitative variegation’ (2010a: 57). Which means: the problem arises from the very ordinary consideration that there are many things in the world, each separate and distinct from the other: there is my laptop, there are my hands, et cetera. For the monist, who wants to claim that everything is the expression of one thing or principle, the ‘information that the world is heterogenous’ is a problem indeed. If everything is one thing, how can there be many things? How can the one thing that there is be both one and many, or become many things?

This seems to be a contradictory concept: to become many, the one would have to cease being one single entity and divide itself into separate things. Precisely for this seemingly unresolvable contradiction the problem has been used to show the implausibility of monism. This happened, for instance, within the dispute between the neo-Hegelian idealist F. H. Bradley, and the founders of analytic philosophy, Bertrand Russell and G. E. Moore. Roughly put, the argument was: that something could be both one and many is a contradictory claim, and therefore it is impossible. This means, either there is only one thing, or there are many. Given this aut-aut, Bradley claimed that manifoldness and relationality are a logical impossibility, and that there must be in fact only one, non-relational entity. In contrast, Russell and Moore defended pluralism as the only way to preserve common-sense intuition and the validity of mathematical truths such as the validity of relations of asymmetry (Russell Reference Russell2010: 2; see also Moore Reference Moore and Moore1993: 165–66; Bradley Reference Bradley1893; Reference Bradley1926).Footnote ² Russell and Moore’s criticism was enough to ban monism from analytic metaphysics for a while. And yet, while common-sense intuition still supports a pluralist picture, today’s empirical evidence challenges the pluralist assumption that everything is made of ‘wee bits of matter’ (Schaffer Reference Schaffer2010a: 50), and rather points at a fundamental unity preceding things and constraining their qualities and causal powers.Footnote ³ Thus, monism is being reconsidered as a viable metaphysical theory, better accommodating not only empirical evidence, but also phenomena of modal interconnectedness (Schaffer Reference Schaffer, Chalmers, Manley and Wasserman2009; Reference Schaffer2010a; Reference Schaffer2010b; Reference Schaffer and Zalta2018). Other reasons behind the renewed interest in monism are monism’s promise of a ‘simple ontology’,Footnote ⁴ and the promise of the rational explicability of everything (Della Rocca Reference Della Rocca2010). Yet, none of this is sufficient for a full vindication of monism. What is necessary in order to defend monism is (at least) to show that it holds from a philosophical point of view: that is, to show if and how exactly a monist outlook could account for the world. To this aim, solving the problem of heterogeneity (that is: explaining how things can be both one and many) is pivotal.

Depending on how they answer the problem of heterogeneity, contemporary monist proposals can be divided into:

1. (a) Michael Della Rocca’s strict monism, which rejects the problem of heterogeneity by reducing its premises ad absurdum;

2. (b) Terry Horgan and Mathiasz Potrč’s blobjectivism, which accommodates the worry about heterogeneity through recourse to contextualist semantics; and

3. (c) Jonathan Schaffer’s priority monism, which solves the problem of heterogeneity by revising the kind of ontological dependence connecting the one to the many.

In the following sections, I will briefly discuss each position, showing that none of these views succeeds in establishing a satisfactory solution to the problem of heterogeneity. As will become clearer below, the main issue with these proposals is that they all solve the problem of heterogeneity by (more or less drastically) deflating it.

I.ii. Strict monism

Strict monism’s main claim is that there are ‘no divisions in the world, no multiplicity’ (Della Rocca Reference Della Rocca2021: 1): there is only one, indivisible thing. This conclusion is reached through a reductio of the very notion of explanation as the fundamental structure of human knowledge and as modelled on the principle of sufficient reason (PSR).Footnote ⁵ Roughly put, the reductio is achieved through the following argument: both the PSR and the possibility of explanation entail a distinction between explanans and explanandum, or ground and grounded, and are only valid if everything can be explained, or if everything has a reason. Yet, the distinction between ground and grounded reveals itself impossible once explanation or the PSR is applied to the fact of existence: in this case, in fact, the ground of the existence of things would entail that ground and grounded are both distinct and the same.

While many would take this outcome to mean that no proper explanation of the fact of existence of things is possible, strict monists argue that it is the existence of many things which, since it cannot be grounded, must be impossible. Indeed, this latter solution is the only way to preserve the validity of explanation: Within a strict interpretation of the PSR, the validity of explanations can only be maintained if and only if everything has a reason. Thus, either anything that lacks a reason is impossible and non-existent, or nothing can have an explanation in the first place. Thus, there must be only one thing and drawing any distinctions within it is a logical mistake. From this perspective, the premises of the problem of heterogeneity are reduced ad absurdum: the fact that something is both one and many is never a possibility because it entails the introduction of impossible distinctions.

The problem with this negative or deflationist approach to the problem of heterogeneity is that it leaves one question unanswered, which is substantial for the defence of strict monism’s main claim that ‘there are no distinctions’. Namely, even if the fact that there are many things is a logical impossibility, it remains true that we experience the world as manifold. Where does this illusion, or logical mistake, come from? Strict monism does not provide an answer to this question, and yet without an answer it cannot legitimately reduce all distinctions to one: until we demonstrate how the illusion of the many is produced out of the one, at least the distinction between the illusion of the many and the truth of the one would remain. Thus, in order to establish an argument in support of strict monism, a substantial, and not just a deflationary answer to the problem of heterogeneity is needed. As I will show below, Hegel uses a similar argument to reject mystical or transcendental versions of monism like Della Rocca’s.

I.iii. Blobjectivism

Blobjectivism is a theory defended by Terry Horgan and Mathiasz Potrč. From an ontological point of view, blobjectivists claim that there is only one concrete object, which they call ‘blobject’ and which is characterized by internal state-variations (Horgan and Potrč Reference Horgan and Potrč2000). This allows us to preserve at least partial agreement with common-sense and empirical evidence: everything that we experience, cognize and describe as a discreet entity, is in fact the effect of state variations within the one existing blobject. This conclusion is achieved through a series of arguments, the main one being based on the impossibility of ontological vagueness.

Roughly put: all individual terms used to refer to individual objects construe these objects as vague or boundaryless,Footnote ⁶ which makes it hard to account for direct ontological referents. For blobjectivists, this implies ontological impossibility (Horgan and Potrč Reference Horgan and Potrč2000: 14–17; Reference Horgan, Potrč and Goff2012: 59).Footnote ⁷ Thus, all that is left for ontology to quantify over are simple, precise objects, or ‘snobjects’, and ontological parsimony requires that we assume that there is only one of them (Horgan and Potrč Reference Horgan and Potrč2000: 17–20; Reference Horgan and Potrč2009). To explain why we nevertheless experience and cognize the world as a set of discrete entities, blobjectivists recur to contextualist semantics, arguing that the terms we use to refer to discrete things are verified by standards internal to the language in which they are used and by indirect correspondence. With this contextual semantic integration, the problem of heterogeneity appears to be solved: we have a way of explaining how the blobject is one and many, although the many are not directly grounded in the blobject and are not as ‘real’ as the blobject. Yet, the blobjectivist solution presents a few problems. Firstly, it exchanges ontological parsimony for a significant degree of semantic complexity (Schaffer Reference Schaffer and Goff2012). Secondly, since for blobjectivists any two apparently distinct language posits are ultimately the same thing, true relationships of differentiation and asymmetry between particulars (and thus ‘true’ heterogeneity) remain impossible (Schaffer Reference Schaffer and Zalta2018). Thirdly, blobjectivism infers the blobject’s heterogeneity from the fact that we speak of discrete entities. Yet, it does not ground our object-positing discourses in ontology, thus leaving this inference ultimately unsubstantiated. If our talk of manifoldness and becoming has no direct ontological correspondence, how can we be sure that there is anything remotely close to heterogeneity and becoming in the blobject at all? This is not just an epistemic, but also a metaphysical issue. In fact, it can only be answered by providing an account of a metaphysical structure that allows the blobject to be variable and complex, that is, by giving a metaphysical, and not just semantic, answer to the problem of heterogeneity.

I.iv. Priority monism

Priority monism is defended by Jonathan Schaffer and sets out to solve the problem of heterogeneity by revising the ontological dependence between the one and the many, so that monism becomes compatible with existence pluralism. Schaffer advances several arguments to defend his priority monism, the most important one being a revised version of the traditional neo-Hegelian argument for the ‘internal relatedness of all things’ (Schaffer Reference Schaffer2010b). The traditional version of the argument was based on the idea that the existence of things is grounded in their reciprocal relations. This either leads to reducing the manifold to a one, a non-relational Absolute—as in Bradley’s monism—or to a strict necessitarianism, according to which all things exist necessarily: if one thing ‘were to fail to exist, then everything would fail to exist’ (Schaffer Reference Schaffer2010b: 349). Schaffer substitutes the traditional notion of internal relation with a weaker one, which he calls the internal_constraining relation, or priority, and which does not ground the fact that the many exist, but only constrains the way in which they exist. Namely, the internal_constraining relation only requires that things exist in ways that are compatible with the existence of all other things existing alongside them. Thus, the unity grounding them is the set of all co-existing things, and not an essential substrate like Bradley’s Absolute. However, the substitution of the internal relation with the internal_constraining relation results in a trivialization of the problem of heterogeneity. Since, from the point of view of priority monism, the one only constrains the essential qualities of the many and does not ‘lend existence’ to them, it need not become non-identical with itself to be heterogenous (Schaffer Reference Schaffer2010a). This seems to be a very promising solution to the problem of heterogeneity because it does not entail the self-refuting conclusion of strict monism and neither does it rely on heavy semantic correctives. Yet, priority monism does face a problem that more traditional understandings of ontological dependence would have avoided, namely: it has a very heavy ontology. Indeed, the claim that the one is not lending existence to the many commits priority monism to quantify over everything there is in the world, plus the unity of all these things.

Schaffer addresses this worry by claiming that priority distinguishes between fundamental (i.e. prior) and derivative (i.e. posterior) entities, thereby allowing the theory to only quantify over the fundamental one(s): the derivative entities are an ‘ontological free lunch’ as ‘already latent’ within fundamental entities (Schaffer Reference Schaffer, Chalmers, Manley and Wasserman2009: 377–78; see also Reference Schaffer2010b: 346; Reference Schaffer and Zalta2018: §3.1.2).

Priority monism, then, should quantify over only the one entity it considers fundamental, which is the world, as the totality of existing things. The problem with this solution is that the idea of an ‘ontological free lunch’Footnote ⁸ requires a form of ontological dependence which is much stronger than the one entailed by the internal_constraining relation: as ‘latent’ within fundamental entities, derivative ones seem to be dependent on the former for more than just their essential qualities. Indeed, they must, in some sense, ‘be made’ of them (Lebens Reference Lebens2017; Della Rocca Reference Della Rocca2021: 197–218, 226–59). Thus, the priority monist must choose; either she makes her theory compatible with existence pluralism, or she grants her theory a simple ontology.Footnote ⁹

In the first case, priority monism would not ground the fact of the existence of things in the whole that is their unity, but only some of their essential qualities. This is not sufficient to grant priority monism a simple ontology: as mere modal constraint of essential qualities, priority does not grant any form of ontological reduction of the many to the one. To use Schaffer’s terminology, it is unclear how parts would be ‘derivative’ from the (fundamental) whole. This poses a further problem: if the world as prior only constrains the essential qualities of its parts, how exactly the world turns out to be depends on how each individual part relates to the others in those respects that are not constrained by the whole. Under this latter respect, the world would be posterior.Footnote ¹⁰

In the second case, the relation of priority will have to be a form of strong ontological dependence to grant priority monism a simple ontology. In this scenario, the problem of heterogeneity returns through the back door.

To sum up:

1. 1. All contemporary proposals try to solve the problem of heterogeneity either by reducing or trivializing its importance, or by demoting its relevance to a field other than ontology or metaphysics. This strategy never works. To truly defend their coherence, all these theories would have to face the question of heterogeneity head on.

2. 2. The problem of heterogeneity can be solved by an understanding of ontological dependence strong enough to make the many ontologically reducible to the one, and weak enough to allow for the many to be there as concrete and distinct. Schaffer’s notion of priority comes close to this understanding but ultimately fails, because it is too weak to make the many ontologically reducible to the one.

I believe that Hegel has a better solution, and I believe this solution can be found in the first chapter of Hegel’s Doctrine of Essence (DoE), where he introduces the structure of essence as ‘absolute negativity’ and ‘reflection’. I take this structure to be the core, stripped-down version of the essential structure of being or reality as being both a unity and a set of manifold, individual and fully ontologically consistent entities (something Hegel will present as the Reciprocal Relation, or the Concept). Thus, I believe that in essence as ‘absolute negativity’ and ‘reflection’ we find a concise presentation of Hegel’s solution to the problem of heterogeneity. The latter provides ample resources for answering my main question regarding Hegel’s account of the ontological dependence relation between the one and the many. However, before discussing this in further detail, it must be shown that Hegel is committed to a monist solution in the first place. While monist interpretations of Hegel have gained some traction (McNulty Reference McNulty2022; Moss Reference Moss2020), this reading is still not uncontroversial. I will also have to demonstrate that the first sections of DoE do indeed contain Hegel’s solution to the problem of heterogeneity. Finally, I will show why Hegel’s notion of essence as ‘absolute negativity’ or ‘reflection’ is successful in resolving the problem of heterogeneity, without running into the difficulties that compromise contemporary positions.

II.i. Was Hegel even a monist?

One direct way to establish whether Hegel was a monist or not is to look at what he took to be the task of his own philosophy. If he believed (his) philosophy should ground the manifoldness of everything in one single thing, then chances are he was a monist. I believe the first paragraph of the Encyclopaedia already says enough on the matter:

The passage presents the problem of heterogeneity as the core question of philosophy and religion. Both are committed to the claim that there is one truth (philosophy in the language of the concept, or from a speculative standpoint, religion in the language of representation). Thus, philosophy, just like religion, is committed to showing that all there is, is true in virtue of, or as an expression of, this one truth. In order to do so, philosophy focuses on the relation between truth, as something that is one, and the finite, as something that is manifold and yet nothing but the same one truth there is. Hence, philosophy is committed to provide a solution to the problem of heterogeneity. To indulge the sceptic, I will argue for this interpretation by looking at Hegel’s discussion of metaphysics in the Encyclopaedia’s Vorbegriff. As is well known, it is controversial to what extent Hegel attributes a metaphysical character to his own philosophical project.Footnote ¹² The discussion of metaphysics in the Vorbegriff shows what exactly Hegel did and did not like about traditional metaphysics, and what aspects of metaphysical inquiry he wants to preserve. This is relevant for the purposes of this article, because what Hegel appreciates about traditional metaphysics is precisely its commitment to monism and to solving the question of heterogeneity. This commitment was stunted by an insufficient methodology, which Hegel criticized and which he clearly distanced himself from.Footnote ¹³ If we look at §§26–27, metaphysics is defined as a ‘naïve manner of proceeding’ (ENZ: §26), for which ‘it is possible […] to be […] genuine speculative philosophizing in terms of its content’ (ENZ: §27) and containing the belief that ‘what the objects truly are’ can be known through ‘thinking things over’ (ENZ: §26). It is precisely this belief that makes metaphysics potentially speculative, at least in its content.Footnote ¹⁴ In §30, we discover that this truth, which is the object of metaphysical inquiry, is itself not just a regular object: ‘Its objects were totalities, to be sure, which in and of themselves belong to reason, to the thinking of the in-itself concrete universal—soul, world, God’ (ENZ: §30).

Hegel takes no issue with metaphysics’ ambition to know these objects: his critique only highlights the inadequacy of the procedure adopted by traditional metaphysics to know them (and, through them, ‘what things truly are’). Namely, Hegel identifies the main flaw of traditional metaphysics in its reliance on finite thought and predication. This forces metaphysics to give representative content to its determinations, and to consider these determinations as rigidly separated one from the other (ENZ: §28). For this reason, the totalities that are the objects of metaphysical inquiry are identified through images (God, soul, world), and not through concepts, and, most importantly, they cannot be understood in any other form than as empty, abstract simples devoid of any determination:

This is an effect of predication, which metaphysics assumes as the form of truth, and which brings the separation between finite thought determinations to bear on the subject-predicate distinction:

Within the framework of finite thinking and predication, the connection between subject and predicate remains something external; something established by the philosopher who is operating the predication and not produced by the subject of the sentence itself. The reason behind this is finite thought’s inability to think a thing’s individuation beyond identity: something is either itself, or not itself. In the case in point: something is either an object of reason, an infinite, absolute, all-encompassing totality, or it is something finite. The two things are incommensurably different, and there seems to be no way to bridge the gap between them (ENZ: §29). As a consequence, metaphysics gets caught up in a series of paradoxes. When the relation between subject and predicate is external, the subject is not only abstract and undetermined, but it is also finite: it is defined by the predicates, as that which is other than the predicate. Such limitation does not fit the notion of the objects of metaphysics as totalities, which should be absolute, i.e. not dependent on anything. That being said, finite thinking can only conceive of internal relations in the terms of simple identification. This either dissolves the manifoldness of the predicates into the objects of metaphysics as abstract, seamless unities, or disperses the unity of the objects of metaphysics into manifoldness. In both cases, the character of totality proper of the objects of metaphysics is lost. They are either one, but simple, or many, but not unitary. This point is made very clearly in the discussion of theologia rationalis in §36A:

Hegel is clearly unhappy with these alternatives. Previously in §36A, he describes the corresponding conception of God as ‘pure reality or positivity’, and as ‘the dead product of modern Enlightenment’. Nevertheless, he remains convinced that the totality, which metaphysics could only vaguely represent and not conceptually grasp, is necessary to fully account for finite being’s existence. Indeed, in relation to the determinations of ontology, he says:

To sum up: Hegel’s discussion of metaphysics as the first position of thought proves that he regarded traditional metaphysics’ monist ambitions rather highly. His criticism focused on metaphysics’ methodology and epistemic framework, not on its goals. In this sense, it could be regarded as a kind of immanent critique: the goal of metaphysics is good, but its methodology is not good enough. This is coherent with what Hegel says of the goal of philosophy in §1: demonstrating that there is a unitary truth of all things requires figuring out the relationship between this truth and the finite. Any account of this truth failing to clarify this relation (such as those provided by traditional metaphysics) is insufficient. Overcoming this insufficiency requires non-representative, non-finite thinking, as well as an understanding of internal relations other than as simple identity. Hegel’s Logic develops from such a framework, relying on infinite, speculative, or ‘objective’ thinking. Precisely this outlook makes the Logic ‘coincide’ with metaphysics (ENZ: §24). This coincidence should be read in terms of an immanent critique: the Logic takes on the same task as metaphysics, but from a different perspective, which allows it to carry it on to completion.Footnote ¹⁵

II.ii. Why essence?

I believe that Hegel’s solution to the problem of heterogeneity is first presented in DoE, and that a stripped-down, essential version of it can be found in the notion of essence as absolute negativity and reflection introduced in the first chapter. Some readers may have worries about this textual focus, which I will illustrate and address here, before moving on to analysing essence as absolute negativity and reflection.

First, it might be felt that Hegel’s definitive answer to the problem of heterogeneity only comes at the end of DoE, through Reciprocal Relation as the prefiguration of the Concept. This is certainly true. However, the structure Hegel presents at the transition from Subjective to Objective Logic in a very dense and complex way, is the same as the one we find at the beginning of DoE. This will become clearer once I have discussed the idea of essence as absolute negativity and reflection in section II.v. That said, already at this point we can shed some light on the issue by addressing a second possible worry related to the philosophical function of DoE as a whole.

Many readers conceive of DoE as a merely destructive enterprise, refuting traditional metaphysical understandings of essence. From this perspective, it seems pointless to focus on the pars destruens of Hegel’s argument rather than engaging directly with the Doctrine of the Concept (DoC). However, this perspective underestimates the intertwinement of critique and constructive theorizing in Hegel’s Logic. Like Hegel’s critique of metaphysics in the Encyclopaedia (and expanding it), DoE is an immanent critique.Footnote ¹⁶ That means, the critical claims articulated in DoE always already contain a prefiguration of the solution. This is coherent with Hegel’s overall method in the Science of Logic, which requires the implications of the previous determination of thought to be made explicit in the next one, and to thereby deduce these determinations immanently.

This is especially true of DoE, the overall task of which is to grasp the notion of essence as something that is ‘in-and-for-itself’. This notion is already contained in essence as it emerges from Being, but only ‘in itself’: essence is being ‘in and for itself’, but ‘in itself’. This means that essence emerges as an absolute unity, which is non-determined, or non-limited by any external determination which could make it finite. Furthermore, essence is supposedly grounding Being, and thus has Being as its part or as its determination. Yet, essence remains determined as finite by its opposition to Being. In other words: essence is determined in a way that leaves Being out of it as an external limit. Hegel calls this a presupposition: the idea of essence as the truth of Being is dependent of the presupposition of there being Being. This latter fact has not yet been shown as something that depends on essence, or that essence posited. It is assumed as a fact, and essence is defined by being the negation of this fact, as the opposite of Being.

The task of essence is to overcome this characterization, and to become what it is ‘in itself’, to realize its concept, or its absoluteness, by removing the presupposition of Being as its other or its opposite:

As I will show below, Reflection is the first determination that manages to grasp the being of essence in and for itself.Footnote ¹⁷ Thus, Reflection offers a concise picture of the kind of revision of ontological dependence Hegel introduces as a solution to the problem of heterogeneity. It is this idea I will engage with in further detail below and for this purpose Hegel’s discourse on Essence, especially the Reflection chapter, is indeed a promising textual focus.

For this purpose, a detailed discussion of DoC actually turns out to be less helpful than the suggested exegesis of DoE. For it should be noted that the starting point of DoC is the standpoint of the achieved unity of the Concept and of its self-mediation. This standpoint is less effective for emphasizing the strong ontological consistency that Hegel’s solution to the problem of heterogeneity grants to finite particulars, because it emphasizes the mediated aspect of the manifold determinations of being (that is: their unity) over their plurality, which is in turn emphasized in DoE. This latter aspect is crucial to appreciate Hegel’s relevance for the contemporary monism renaissance, and it is much more visible in DoE, because granting full ontological consistency to the manifold determinations of Being is precisely the goal DoE must achieve in order to be ‘in and for itself’.

II.iii. Existence of essence as heterogeneity

Essence emerges from Measure, the last determination of the Doctrine of Being (DoB), as an undetermined, abstract totality, which is the truth of the manifold determinations of Being:

The introduction to DoE reproduces the critique Hegel levels against metaphysics in the Encyclopaedia, specifying that essence should not be considered as the result of a ‘pathway of knowledge’ (SL: 337/241). By this expression Hegel means the definition of essence through the abstraction or negation of all its possible determinations, as an ‘external’ procedure, performed by an agent which is not essence itself, and as an act which is not relevant to the definition and individuation of essence itself (SL: 337–38/241–42). This would turn essence into an artifact, produced by the philosopher performing the abstraction, and therefore would not grant essence an internal relation to its determinations. This leaves the abstracted determinations of essence irreducible to essence itself, as something external to essence, as its immediate other or opposite, and makes essence ultimately limited by them. This would make essence not a truth underlying being, as essence should be, but just another determination within being:

The way to overcome this shortcoming is contained in its critique: essence must be conceived as having an internal relationship to its determinations; it should not be defined through abstraction from or negation of determination, but rather through inclusion of determination. DoB has already made a significant contribution to this aim: it showed that it is Being itself—and not an external abstracting subject—that negates its determinations in Measure. Negation of determination (or, as Hegel will call it, negativity) is proper of Being. Being does not need an external intervention to be connected or related to essence:

Yet, this is not sufficient in order to reach a full understanding of essence: the fact that there is determination remains a brute fact, until it is demonstrated that essence gives itself the very determination that it negates in order to realize itself as a unity. Until then, essence remains ‘for another’ and only ‘in itself’: it depends on determination’s being there, as an external other limiting it. In Hegel’s terminology, essence needs to give itself existence (Dasein) in order to be the ‘truth of being’, or the grounding unity, that its concept requires it to be:

In the question of how essence can give itself existence we have another formulation of the problem of heterogeneity. To ask: ‘How can essence give itself determination as an undetermined unity?’ is another way of asking: ‘How can the one be many?’.

II.iv. Hegel’s criticism of traditional ontological dependence

In sections ‘A. The essential and the unessential’ and ‘B. Shine’ Hegel considers the two traditional ways in which the relation between essence and its existence has been understood, showing how both are insufficient. As the essential, essence is conceived in a way very similar to the result of a ‘pathway of knowledge’, except for the fact that the idea of essence as an abstract, undetermined unity opposed over and against determined, finite being(s) is not produced by an abstraction operated by an external subject. As the essential, essence appears as an undetermined substrate which is the truth of the inessential, the manifold determinations that it assumes in addition to being this substrate. These latter determinations are considered aspects that are accessory to the definition of what the essential is. We have then two opposed spheres, the one of the manifold determinations of being, and the one of the undetermined unity of essence. Since the determinations of being appear to negate themselves into essence as their truth, this negation is first understood as indicating some kind of metaphysical hierarchy: essence is what is essential, truly there. Everything else is unessential: it has a lower degree of existence but is still somehow there. Thus, anything that is not the essential remains outside of it as a separate sphere of being, without inclusion in the sphere of the essential. Thus, essence remains limited and determined by being as an other that stands over against it, and is nothing but yet another determinate being, individuated by the determinate negation of its other as its limit. As we have seen above, this understanding is insufficient in order to fulfil the concept of essence as the ‘truth of being’:

To avoid this outcome, determination, here conceived as the unessential, needs to be included in the definition of essence. In other words: being, in all its aspects, needs to be understood as the existence of essence, or as something that essence is. Otherwise, essence would be dependent on something else, which it would need to negate in order to determine itself as unity. This contradicts the absoluteness or being ‘in-and-for-itself’ which is characteristic of essence as ‘the truth’, or the ground,Footnote ¹⁸ of being.

Hegel is here arguing against theological understandings of essence as an absolute, transcendent truth that has no connection to the realm of the finite. With an eye to the contemporary debate, though, this critique confirms that Hegel’s overcoming of traditional accounts of essence will not go in the direction of Schaffer’s priority monism.

As we have seen above, priority monism excludes the possibility that the one grounds the existence of things. In priority monism the existence of things is assumed from the start and priority only constrains or grounds some aspects, or qualities, of their existence. In Hegel’s eyes, this limitation of the ontological dependence of things on the whole would make the whole a version of the ‘essential’, and as such limited by all the aspects of the (inessential, or to use Schaffer’s term ‘derivative’) things it does not ground. Hegel is indeed after a principle that could ground the totality of the existence of its determinations, and not just some aspects of them.Footnote ¹⁹ Surely, Schaffer would not be particularly bothered to have his monism distinguished from Hegel’s. Yet, if there was a way to account for the fact of the existence of things without the need to give up on ontological pluralism, Schaffer’s limitation of ontological dependence would not be necessary.

In ‘B. Shine’ Hegel considers the most obvious way in which the opposition between the essential and the inessential as two external others could be overcome. This perspective gets one thing right: everything that exists must be understood as an integral aspect of essence. Thus, being must become shine: a determination that essence gives itself, and which is nothing but essence. ‘Shine is essence itself in the determinateness of being […]. For essence is what stands on its own: it exists as self-mediating through a negation which it itself is’ (SL: 344/248).

Yet, the understanding of being as shine still conceptualizes the relationship between essence and being in terms of determined, or simple, negation. The unity of essence is presupposed as a starting point, and determination is achieved through the negation of this positive unity. This means that manifoldness is actually nothing: it is only the negation of essence’s unity, in virtue of which it came to exist. Its existence is entirely reducible to the unity of essence: the existence of something is nothing, because its determination is nothing but the negation through which essence negated its unity to give it existence:

On this account, essence is no longer limited by an external other. At the same time, however, the account also creates a new problem: manifoldness is entirely reducible to the unity of essence and thus, truly not there at all. Shine is nothing but its own negation through which the unity of essence is realized: manifoldness and existence are not really there, or, they are only an illusion, an appearance.Footnote ²⁰ This is not sufficient to give essence existence because here shine and essence are ultimately the same thing, so there is not essence and its existence, but just essence. This shows that in order to be ‘in and for itself’, essence not only needs to determine itself. Rather, it must determine itself in a true other, resisting and opposing its unity and identity. Indeed, Hegel points out that despite the seemingly complete reduction of the many to the one in Shine, there is nonetheless something left untouched by this reduction. This other, that shine excludes, is being’s immediacy. The latter remains independent from essence and resists its mediation. To include this immediacy and otherness, essence needs to find a way of recognizing this irreducible otherness as a moment of its own self-realization. In other words, the existence acquired by essence must be such as to not be (fully) reduced to its unity, i.e. the unity of essence is fully realized only in positing its existence as an other that withstands unity. Only in the positing of its other as its opposite, as that which contradicts its unity, is essence’s unity truly realized:

Hegel shows that the traditional understanding of ontological dependence, granting full reduction of the many to the one on the basis of the fact that these are ‘made of’, i.e. derive the fact of their existence from, the one, is dissatisfactory. This understanding of ontological dependence is both too strong and too weak: the reduction of the many to the one is too radical, therefore it becomes incapable of including the many as many, and not as the one in different form. This understanding of grounding is self-refuting: while it claims to fully reduce manifoldness to unity, it ends up leaving (true) manifoldness outside of its reduction. This is rooted in two interconnected mistakes: on the one hand, grounding and self-determination are conceived of only in terms of identity, and, on the other hand, essence is understood as an existence before and independently of its determination. Indeed, the only way to think of the one being both one and many, is to think of it not as simple identity with itself, but rather as differing from itself.Footnote ²¹

In order to show more precisely how that works, we will have to take into consideration Hegel’s account of essence as Reflection. Before doing that, however, I should like to point out that the criticism of traditional understandings of essence as shine applies to Della Rocca’s position, as well as to blobjectivism. Hegel’s position amounts to the following: without giving itself existence, essence could not even be essence. Multiplicity and immediacy are inescapable features of being: DoB has demonstrated this showing that Being, passing through Nothing and Becoming, needs to become Determinate Being (Dasein).Footnote ²² While the passing of DoB into DoE demonstrates that this multiplicity and immediacy can only be appreciated from the standpoint of a unity grounding them, this unity is a unity only if there are the many of which it is a unity (and only if it has posited the many itself). Reducing the one’s distinctness to an illusion (as Della Rocca does), or to a superficial effect of the one’s unity (as blobjectivism does), is not sufficient, because it still does not account for that distinctness being there as something other than the one’s unity.Footnote ²³ Hegel is here emphasizing the same self-refuting nature of the traditional understanding of ontological dependence that Della Rocca also highlights. Just like Della Rocca, Hegel is showing that the traditional understanding of ontological dependence cannot truly account for the difference of the relata, thereby excluding the possibility that there are any two distinct things. Contrary to Della Rocca, Hegel takes this self-refuting nature as the sign that this understanding of grounding, or ontological dependence, is insufficient and should be substituted by a different one that is not self-refuting. He does not insist on assuming the validity of the traditional understanding of grounding at the cost of giving up the possibility of rationally making sense of the problem of heterogeneity.

To sum up: like priority monism, Hegel is after a kind of ontological pluralism compatible with monism. He claims that there are many things which are ‘immediate’, or which cannot be reduced to the unitary principle, or essence, grounding them. He aims to achieve this through a revision of the kind of ontological dependence connecting essence and its existence, or the one and the many, because he finds the traditional one self-refuting. Yet, unlike priority monism, he offers a revision of traditional ontological dependence, which grounds the fact of the existence of the many—and not just some of their qualities. In this way, Hegel confronts the problem of heterogeneity head on, instead of deflating it.

II.v. Reflection as a solution to the problem of heterogeneity

As shown in ‘B. Shine’, Hegel wants to depart from the understanding of essence as a substantial entity existing ‘prior’ to determination and lending existence to it. After all, essence emerged from Measure as the movement of negation through which the determinations of being negate themselves and reveal their relativity: ‘Essence is what it is, not through a negativity foreign to it, but through one which is its own—the infinite movement of being […]. It is itself this negativity’ (SL: 338/242).

Essence is presented here exclusively in terms of a movement of negation, or as being itself negativity. This account entails a very peculiar relation of ontological dependence between essence, as the ‘truth of being’, and being’s determination. Hegel calls this relation the ‘absolute self-repelling’ of essence as reflection, or the movement of double negation. As double negation, essence is conceived as a negative unity: the one negativity in which the determinations of being are negated. Thus, essence’s unity is not static coincidence, or simple identity, with itself, but rather negativity referring to itself. Being the negation of the determinations into its unity, essence is referring the negation of determination to itself as negativity, which means—it is negating itself. Thus, essence’s unity is not realized in the coincidence, or identification, of itself with itself, and it is rather realized in its immediate differing from itself:Footnote ²⁴ ‘This self-referring negativity is therefore the negating of itself […]. It consists, therefore, in being itself and not being itself, and the two in one unity’ (SL: 346/250).

As ‘absolute counter-repelling’, essence posits its determinations as immediate and independent from its unity. Indeed, double negation produces positive, individuated, fully ontologically consistent determinations: the negation of a negation is a positivity; not-not-something is something. This is contrary to what happened in the traditional understanding of ontological dependence, which regarded determination as nothing but the negative of essence. There, essence negated its unity and posited its determination as not-this-unity. This simple negation was also what made it possible to reduce things entirely to the unity of essence: they were nothing but the negative of essence, something defined only and always with reference to it. Instead, on Hegel’s double negation model, the negation that signals the reducibility of determination to essence, the one which would refer the determinations to essence and would consider them as nothing but the negative of its unity, is itself negated. Essence posits its determination by negating itself as the negation of determination, or by negating that very negation that made determination reducible to its unity:

As double negation, or absolute negativity, essence hides (or ‘sublates’) its mediation, or grounding, of determination. Since essence’s unity is negativity, essence’s return to itself through the negation of determination amounts to the positing of determination not as a negative, fully reducible as in Shine, but as a positive: being the result of double negation, determination is here the result of the negation of its very reduction as (just) the negative of essence. To put it in simpler words: essence does not pose its determination as dependent and reducible to itself, but rather as immediate and irreducible.

Hegel calls this kind of determination a presupposition, to highlight its resistance over against essence, and its appearance of otherness and independence with respect to essence. As a presupposition, determination resists essence’s reduction and appears like an other, that essence can negate (or from which it can ‘turn back’) to realize its unity:

The presupposed is in fact posited by essence itself, it is no external other to essence: it is the product of essence’s activity of self-realization. However, differently from how it was in Shine or in the Essential/Unessential, it is not just the aspects that are reducible to essence’s unity that are a product of essence’s positing in the presupposed. Indeed, and most importantly, in positing the presupposed essence is positing also in the aspects that are irreducible to its unity. For this reason, the presupposed has full ontological consistency as an individual, finite determination that appears immediate and independent from the very unity that is positing it, i.e. essence.

Thus, essence’s determination as presupposition realizes essence’s existence, as well as its being ‘in-and-for-itself’, thereby also offering a more convincing solution to the problem of heterogeneity.Footnote ²⁵ This is because, with Hegel’s account, we finally arrive at an understanding of unity which can determine itself in determinations that are true others to itself. This delivers a notion of unity according to which the one is realized (only) in its being many, or, to say the same thing, it is one and many at the same time.

But what exactly does this mean outside of Hegel’s jargon? Is there a candidate in the world that could embody essence as absolute negativity? And could the designation of essence as absolute negativity not hint at the fact that, according to Hegel, there is no such thing as a unity grounding the many?

Schaffer (Reference Schaffer2010b) relates his philosophical discussion back to scientific discourse by presenting ‘causal connectedness (given causal essentialism)’ (Reference Schaffer2010b: 362), ‘spatiotemporal relatedness (given structuralist supersubstantivalism)’ (Reference Schaffer2010b: 365), and ‘being worldmates (given counterpart theory)’ (Reference Schaffer2010b: 356) as an analogue to his account of priority. While this is certainly an interesting approach, it would go beyond the scope of this paper to identify an equivalent of Hegelian absolute negativity in contemporary scientific discourse. However, I can try to bring what Hegel says closer to everyday understanding.

Essence is a negative unity, a unity of negation: all beings are one in their being negated. This being-negated happens in their relation to their others, and in their having an end, in their dying or being destroyed.Footnote ²⁶ This negativity, in which determinations dissolve, is indeed one and the same, a negative unity, defined by the negation and absence of determination.

Yet, at the same time, this very negativity in which determinations dissolve is the same that individuates them as determined and finite: without this negativity, that gives determinations their limit, there would be no determination at all.Footnote ²⁷ In this sense, all things come from nothing and are made of nothing—where ‘nothing’ is here meant not as a static realm of emptiness, but rather as an activity of self-creation and self-realization driving and underlying all interactions between things. Thus, absolute negativity could be regarded as this reciprocal, negative relation connecting (or, better, distinguishing) all things: something that continues to unfold in an endless process of death and rebirth, of which all things are part. As such, absolute negativity is not a traditional monist principle, whose unity precedes determination. Yet, it is still something ‘more’ than simple determinations, which makes them possible.

The structure of double negativity will only be fully realized in Reciprocal Relation, the last determination of DoE before DoC. There, essence will finally emerge as the unity of these two, self-implicating movements: on the one hand, essence is the movement of negating and recollecting its determinations into a unity (Passive substance) and, on the other hand, essence is the movement of determining itself in free, contingent, determinations negating this unity (Active substance). Nevertheless, Reflection does offer a first formulation of the structure of essence as in-and-for-itself, albeit still from the perspective of the in-itself. In fact, Reflection only demonstrates how essence can give itself existence in general, and not how all of Being, in all its complexity and detail, is indeed the existence of essence as its determination or presupposition.

To fully grasp the implications of this issue, one would have to consider the development of DoE in its entirety. This, however, is far beyond the scope of this article, which has only aimed to understand the essential structure of ontological dependence in Hegel’s solution to the problem of heterogeneity.