American Philosophical Quarterly Volume 56, Number 3, July 2019 ©2019 by the Board of Trustees of the University of Illinois eaCh thinG iS FUnDaMental: aGainSt hylOMOrPhiSM anD hierarChiCal StrUCtUre M. Oreste Fiocco Abstract each thing is fundamental. not only is no thing any more or less real than any other, but no thing is prior to another in any robust ontological sense. thus, no thing can explain the very existence of another, nor account for how another is what it is. this surprising conclusion is reached by undermining two important positions in contemporary metaphysics: hylomorphism and hierarchical views employing socalled building relations, such as grounding. the paper has three main parts. First, it is observed that hylomorphism is alleged by its proponents to solve various philosophical problems. however, it is demonstrated, in light of a compelling account of explanation, that these problems are actually demands to explain what cannot be but inexplicable. Second, it is shown how the argument against hylomorphism illuminates an account of the essence of a thing, thereby providing insight into what it is to exist. this indicates what a thing, in the most general sense, must be and a correlative account of the structure in reality. third, it is argued that this account of structure is incompatible not only with hylomorphism, but also with any hierarchical view of reality. although hylomorphism and the latter views are quite different, representing distinct philosophical traditions, it is maintained that they share untenable accounts of structure and fundamentality and so should be rejected on the same grounds. according to the venerable doctrine of hylomorphism, many things, including familiar concrete objects, are composites of matter and form. this doctrine is supposed to resolve elemental ontological problems concerning change, individuation and unity. i maintain that it cannot solve these problems; indeed, no theory can, for they are not genuine. rather, the putative problems arise from mistaken explanatory objectives stemming from untenable assumptions about what it is to exist. Understanding why these assumptions are misguided-and, thus, why hylomorphism itself is-reveals a more promising ontology, one on which each thing is fundamental. after saying a bit more about hylomorphism, i present briefly the putative problems it is traditionally supposed to solve. examining these in light of a compelling account of explanation reveals that the problems are merely demands to explain what cannot be but inexplicable. For this reason, they should be dismissed. these considerations undercut the motivation for hylomorphism, yet they also illuminate the best way to understand the being, that is, essence of a thing, thereby providing insight into what it is to exist. this indicates what a thing, in the most general sense, must be and a correlative account of the structure in reality. any recognizable version APQ 56_3 text.indd 289 7/2/19 12:18 PM 290 / aMeriCan PhilOSOPhiCal QUarterly of hylomorphism is incompatible with the resulting ontology, as is any hierarchical view, employing socalled building relations, widely accepted in contemporary discussions of metaphysics. Perhaps surprisingly, although hylomorphism and these other views are quite different-representing distinct philosophical traditions-they share an untenable account of structure, and so should be rejected on the same grounds. § i. hylomorphism and its Motivation above, i gloss hylomorphism simply as the doctrine that many things-this human person, that tree, that house, for example-are composites of matter and form. little more can be said about it without inviting dispute. the doctrine originates, of course, with aristotle. like all his views, its expression is elusive; like all his views, it has been the focus of scrutiny and a source of immense controversy since antiquity. thus, exactly what matter is, what a form is, how form and matter compose a thing is not easy to say. nor is it clear how exactly the notions of potentiality and actuality, which are taken to be central to the doctrine, are to be understood.1 What is perhaps less controversial is the motivation for the doctrine: it is supposed to resolve a number of elemental ontological problems. By showing why these problems are illusory, i both undermine the motivation for hylomorphism and also reveal ineluctable ontological theses that are incompatible with the crux of the doctrine. this obviates the need to articulate any version of hylomorphism in great detail. the problems hylomorphism is supposed to solve are explanatory ones. it is thought that if theorizing-be it physical or metaphysical- about reality is to have adequate foundation, certain phenomena, pertaining to the primordial features of reality, must be explained. One such phenomenon is substantial change, the coming into existence and ceasing to be of things such as familiar concrete objects. another is individuation, one thing's being distinct from every other and, hence, being the very thing it is.2 a third phenomenon, the one that has received the most attention in recent discussions of hylomorphism, is that of unity. Unity is exhibited when a multiplicity of things is nonetheless one, the existence of that one whole being accounted for in terms of its parts, those many others. it is not necessary here to consider how hylomorphism is supposed to explain these crucial ontological phenomena, for i am not criticizing any particular attempt to explain individuation or unity (or substantial change). rather, i challenge the key presupposition that underlies the putative problems thought to be resolved by hylomorphism, namely, that each of these ontological phenomena is explicable at all. if indeed none is, any proposed explanation is beside the point-and the lack of explanations is in no way problematic. § ii. individuation, Unity and explanation i do not think it is apt to regard socalled substantial change as change at all (and i think one can hold this without denying that it is impossible for something to come from nothing). thus, i do not see substantial change as being pertinent to hylomorphism in the way it customarily has and set the phenomenon aside to focus on individuation and unity. aristotle introduces hylomorphism in order to explain these phenomena; the prospect of such explanations-especially of unity-remains a significant motivation for adopting the doctrine in contemporary discussions.3 Clearly, then, it is presumed by hylomorphists that individuation and unity are amenable to explanation. i argue in this section, however, that given a compelling account of explanation they are not. i believe that there is a single practice of explanation, operative in all domains in which explanations are tendered, and so the APQ 56_3 text.indd 290 7/2/19 12:18 PM eaCh iS FUnDaMental / 291 following remarks apply to any explanation, whether it be logical, mathematical, physical, metaphysical or what have you. every explanation has both epistemological and ontological dimensions. an explanation (in the sense of an act) is the presentation to some conscious being of an explanation (in the sense of an object). the latter is usually a representation, one that enhances knowledge of some thing(s) in terms of another (or others). hence, an explanation, as act, is an epistemic achievement. Consequently, there are a number of linguistic, conceptual and practical conditions-determined by the epistemic and more general mental states of the conscious being to whom the explanation, as object, is presented-that must be met for this achievement to occur. in addition to these broadly pragmatic aspects, an explanation must have an ontological basis. this is the things in the world-explanandum, explanans and a relation between them-represented by that explanation (in the sense of an object). the relation must be one on which how the former is depends on or is determined by the latter, that is, one whereby the former is as it is because of the latter. Without explanandum, explanans and this relation, one cannot have an explanation: one lacks either the thing(s) about which one's knowledge is to be enhanced or the means of enhancing it. thus, i am propounding here a realist account of explanation, one on which explanation is possible only if there are things in the world standing in appropriately robust relations.4 in defense of such an account, i simply note that any alternative that eschews things in the world to underpin the representation that is the correlative of the act of explanation is left with a practice that is not constrained by reality and, hence, is not legitimately epistemological. an "explanation" that cannot even be regarded as epistemic is no explanation at all. in the context of this realist account, "thing" should be construed as having the utmost generality. By "thing" i do not mean only familiar concrete object or substance (in some other sense). i intend the term to apply to every entity in any ontological category there is. a realist account of explanation, then, has no specific ontological assumptions and so excludes no ontology. it does, however, have a crucial ontological consequence: there is no explanation whose explanandum and explanans is a single thing. One's knowledge cannot be enhanced by the revelation that a thing is as it is because of it. in other words, nothing can explain itself. (though some feature (or part) of a thing can explain an explanandum including a distinct feature of that very thing. Features are things and so the ontological basis of any such explanation involves distinct things.) a representation that does not present something visàvis another (or others) is, at best, merely descriptive; it can be informative, even revealing, but it cannot be explanatory, regardless of its complexity. Consequently, every genuine explanation is based on some thing (or things) in relation to another (or others). the ontological basis of any explanation, therefore, can be represented schematically as aRb, where a is a thing (or plurality of things) that stands in some robust relation, R, to b, some thing (or plurality of things) distinct from a. Whatever R is, however this relation is understood, it must be the case that if it holds, its relata exist. this follows from the cogent assumption that a relation can only relate what exists.5 i maintain, then, that the relata of any genuine explanatory relation are existent things. Some, however, maintain that the relata of such relations, at least with respect to the sort of metaphysical explanations relevant below, are facts.6 there are different accounts of what a fact is. On one, a fact is a complex, including things in the world; it is a state of affairs or some such. On the other account, a fact is a representational entity presenting certain things in the world as they are, that is, presenting certain things truly. if a fact is a APQ 56_3 text.indd 291 7/2/19 12:18 PM 292 / aMeriCan PhilOSOPhiCal QUarterly true representational entity, it is true in virtue of those things in the world that it presents. On either account of facts, therefore, facts constitutively involve things in the world. So even if one maintains that the relata of explanatory relations are facts, the ontological basis of any such explanation is nonetheless ultimately things in the world standing in some relation. Given this realist account of explanation, consider whether it is indeed possible, as the hylomorphist contends, to explain the individuation of some thing, b, that is, to explain what makes b distinct from all other things and so the very thing it is. Suppose it is. there is, then, some representation that enhances one's knowledge of b being the very thing it is in terms of some other thing. this explanation must have an ontological basis. So there is some thing, a, that stands in R to b being the very thing it is such that by standing in this relation, a makes b the very thing it is. But this cannot be so, as can be seen via the following argument. if a makes b be the very thing it is, there is some relation between a and b. in order for b to stand in this relation (or any other) to a (or anything whatsoever), b must exist. however, b cannot exist as any thing other than itself; it must be the very thing it is-namely, b-and, consequently, be distinct from all others. hence, its individuation is a precondition of b standing in any relation and, a fortiori, of standing in R to a. it cannot be by standing in this relation to a, then, that it is made to be the very thing it is. therefore, there cannot be some thing that makes b the very thing it is. if there is no ontological basis for explaining what individuates b, there is no explanation for b being the very thing it is. this argument is totally general and so there is no explaining the individuation of anything. the individuation of a thing is inexplicable. One might challenge this argument by maintaining that it shows merely that if a individuates b, then the two things must coexist. it does not follow from their necessary coexistence, one might contend, that a is not in some sense prior to b. if it is, a is-in some way-more fundamental than b, and so can ground or otherwise determine the individuation of the latter. however, what this sort of response overlooks is that the relational notion of priority employed here is supposed to be explanatory. as such, it is constrained by the norms of explanation. no genuine explanation can require that the explanandum play an instrumental role in permitting the dependence relation on which that explanation is based to hold at all. Were an "explanation" to require this, its underlying dependence relation would rely crucially on what it is supposed to be realizing in the first place. yet if a were to explain the individuation of b, b must be the very thing it is in order for a to stand in a determinative relation to the individuation of b. the holding of this determinative relation would rely crucially on the individuation of b, which is precisely what the relation is supposed to be realizing. thus, the argument does not overlook putative relations of grounding or priority and is not undermined by them; rather, it shows a limit to their applicability: if they hold at all, they cannot underlie explanatory claims of individuation. Maybe it is not surprising that the individuation of a thing is inexplicable. it is plausible to think, with Bishop Butler, that everything is what it is and not another thing. Still, the foregoing is an argument for why the exasperation suggested by the famous dictum is appropriate. there is no explanation for the individuation of a thing because no thing could make another be the very thing it is. if this is correct, and no thing, regardless of category, is individuated by any other, then it undermines what is supposed to be one of the theoretical benefits of hylomorphism. One might concede that the demand for an explanation of individuation is mistaken, yet maintain that the real value of hylomorphism APQ 56_3 text.indd 292 7/2/19 12:18 PM eaCh iS FUnDaMental / 293 is its capacity to explain unity. after all, it is this purported capacity that has prompted several contemporary philosophers to endorse the doctrine.7 i think this attitude is mistaken, however, for the same sort of argument that tells against an explanation for individuation tells against any explanation for the unity of a thing. the impetus for examining the unity of complex things comes from the socalled Problem of the One and the Many, the problem of giving an account of how something with many parts is nonetheless one. this is an ancient problem, but one that has received renewed attention in recent decades as Peter van inwagen's Special Composition Question ("under what conditions do some objects compose something?").8 if there is a solution to this problem (and an answer to this question), it would be an explanation of what it is that makes a multiplicity of things nonetheless one. So suppose, as the hylomorphist contends, that there is some such explanation. there is, then, some representation that enhances one's knowledge of the unity of b, a complex thing, in terms of some other thing. like any explanation, this one, too, must have an ontological basis. in this case, a is some plurality of things that stands in R to b being unified such that by standing in this relation, a makes b unified. But this cannot be so. if a makes b a unity, there is some relation between a and b. in order for b to stand in this relation (or any other) to a (or anything whatsoever), b must exist. however, b cannot exist as any thing other than itself; it must be the very thing it is-namely, b-and, consequently, be what it is, simple or a complex unit as the case might be. in this case b is assumed to be a complex unit. hence, its unity is a precondition of b standing in any relation and, a fortiori, of standing in R to a. it cannot be by standing in this relation to a, then, that it is made to be a complex unit. therefore, there cannot be some thing that makes b unified. if there is no ontological basis for explaining what unifies b, there is no explanation for b being a complex unit. this argument is totally general and so there is no explaining the unity of anything. the unity of a thing is inexplicable. (note that any challenge to this argument on the basis of the supposed priority of a to b can be met mutatis mutandis as was the similar challenge to the conclusion that individuation is inexplicable.) a form cannot make a thing be what that thing is and so, in particular, cannot make it be a complex unit. nothing can do this. thus, the foregoing argument undermines the other putative theoretical benefit of hylomorphism. One might, however, maintain that the argument mischaracterizes the explanation for the unity of a thing provided by the doctrine, holding that the relational form, R, of a thing does not make that thing be what it is by relating a, its multiplicitous matter, to b, that complex unit itself. rather, the form makes the (multiplicitous) matter of the thing be the unified thing.9 this cannot be right, though. Many things cannot be identical to one thing.10 even if they could, and the multiplicitous matter of a thing just were the unified thing, one would not have the means of explaining the unity of that thing. Despite the complexity of the ostensible explanation (in the sense of an object)-namely, the form makes the (multiplicitous) matter of the thing be the unified thing-its ontological basis would be but a single thing, to wit, the unified (multiplicitously) material thing. yet, as argued above, there is no explanation whose basis is a single thing. What appears to be an explanation of the unity of a complex entity is merely a description of a single thing twice over: described once as many, and again as one. together the preceding two arguments demonstrate the nullity of any apparent explanation of the unity of a complex entity. if there is supposed to be any relation other than identity between the many and the one, the putative explanation is belied by the former APQ 56_3 text.indd 293 7/2/19 12:18 PM 294 / aMeriCan PhilOSOPhiCal QUarterly argument; if the many and the one are supposed to be identical, the putative explanation is belied by the latter. these arguments against the possibility of explaining individuation and unity are essentially the same. the basic argument is grounded on the key assumption that every explanation has an ontological basis of existent things in relation. this argument is so simple, yet undermines so much taken for granted, that it has an air of sophistry. the argument, however, is not sophistical; it simply takes very seriously a principle that everyone should accept and traces its consequences. this is the principle that explanation must end. explanation must end in the sense that it must engage and, hence, terminate in the world. explanation ends with the things in the world. this principle is consistent with there being infinite series of things in relation, with some of these explaining others that explain others, etc. note, however, any such series is and must be a series of things. Since any explanation ultimately involves things in some relation, there are limits to explanation. the preceding arguments demonstrate that the individuation and the unity of a thing cannot be explained. the same sort of argument also shows that the existence of a thing-which is a precondition of being in any relation, explanatory or otherwise-cannot be explained, nor can any phenomenon attendant upon the very existence of that thing, notably, its being what it is and, more generally, its being how it is essentially.11 if neither the existence of a thing nor its individuation nor how it is essentially can be explained, in no genuine sense can a thing per se be explained. things are the elements of explanation and so each one itself is beyond its bounds. there is nothing in the world but things (in the most inclusive sense of 'thing') and one cannot explain a thing. it does not follow, however, that there are no explanations at all. although a thing per se is beyond explanation, the arrangement of things-all of them or, given more practical interests, some delimited plurality of them-is amenable to explanation. the arrangement of all things is the structure in the world; some less inclusive arrangement is a structural phenomenon. One can, in principle, explain this structure or the manifold phenomena it comprises. thus, for example, one might explain: why a dresser, which can (and did) exist without being green, is now in fact this color; why a sample of salt and a sample of water, both of which could exist in the absence of any solution, together yield this salty solution; why a cluster of cells, which were (and so, perhaps, could have been) healthy, are nonetheless cancerous; why a society that could be peaceable is riven by war; why a person, capable of performing ever so many actions, is currently mixing batter in the kitchen. in all these examples, the explanandum is not a thing per se but a structural phenomenon. as such, the explanandum is not a thing, but a plurality of them, some things in some relation(s). any explanation requires, of course, that its explanandum exist, lest there be no phenomenon to explain; it requires no less the existence of its explanans, lest there be no thing(s) to illuminate, via some relation, the explanandum. no explanation, then, accounts for the existence of the explanandum, it can only account for why those things are related as they in fact are (when they need not be). the means of this account, and the source of the illumination it provides, is that other thing (or those other things), the explanans, standing in some relation to the former. therefore, whereas arrangements of things can be accounted for in terms of things, at the end of inquiry, the most an inquirer can do with respect to each thing per se is appreciate it, what and how it is essentially and the capacities it has to interact with other things.12 if the justification for endorsing hylomorphism is its capacity to explain the APQ 56_3 text.indd 294 7/2/19 12:18 PM eaCh iS FUnDaMental / 295 individuation and unity of things, then given that there can be no such explanations, there is no reason on these grounds to accept the doctrine. thus, the explanatory expectations that motivate hylomorphism are misguided. the foregoing discussion, however, does more than undermine the reasons for accepting hylomorphism, it provides enough insight into what a thing (in the most general sense) must be to show that any recognizable version of the doctrine is untenable. § iii. things with natures v. natured things there can be no explanation for either the individuation or unity of a thing, ultimately because there can be no thing that in relation to some other makes the latter the very thing it is or makes the latter what it is. however, the form or essence or nature (i use these terms interchangeably) of a thing is supposed to be precisely that which makes that thing be what it is. if there is no such thing, it might seem that the argument of the preceding section has the consequence of undermining essentialism, the general view that there are necessary constraints on the being of a thing. if there is nothing that makes a thing be what it is, this might suggest that a thing need be no ways, that the being of a thing is wholly unconstrained. the foregoing considerations raise, then, the primary ontological question of what exactly a thing is. these considerations do not in any way undermine essentialism; on the contrary, they reveal the most promising version of the view. it would be a mistake to infer from the conclusion that the individuation and unity of a thing are inexplicable that a thing is not the very thing it is or is not what it is. the claim that a thing is not itself is incoherent, as is the claim that it is not what it is. indeed, it seems impossible for something to be a distinct thing and seems no more possible for a thing to fail to be what it is. an account of what a thing is on which a thing need not be what it is, if not just double talk, characterizes a "thing" so ontologically indeterminate as to have no real claim on being. Such an account is not an account of anything at all. thus, if a thing is (or must be) the very thing it is and is (or must be) what it is, although there is nothing that makes it either, this indicates that each thing is sufficient in itself to constrain its individuality and what it is. Given that these constraints on a thing-its being the very thing it is and, hence, being what it is-require it be some ways and not others, there are also these qualitative constraints on being that thing. Moreover, what it is and these further qualitative constraints constrain how that thing interacts with others, thereby constraining those other things. to be, therefore, is to be constrained. a being-a thing-is constrained (and constrains) and is in this sense natured.13 a thing does not have a nature (or essence or form), in the sense that there is something distinct from it, to wit, its nature that determines the individuation of that thing and what it is and, consequently, how it interacts with other things. rather these constraints are inherent to its very being; to be so constrained just is what it is for that thing to exist. Such constraints are how a thing is essentially, yet these ways are not themselves something. thus, each thing is certain ways essentially without having an essence and so each is natured though lacking a nature. One may, if one chooses, talk of the constraints concomitant to its being as the essence (or nature or form) of that thing, but this is quite misleading. Since an essence is nothing at all, any talk that suggests otherwise should be avoided. More importantly, for the reasons given above, any view that reifies essences, treating them as things that make-in an explanatory sense-others be what they are, cannot be right. the essentialist account of what a thing is that i defend here is, then, incompatible with other notable versions of essentialism. locke maintains, in an APQ 56_3 text.indd 295 7/2/19 12:18 PM 296 / aMeriCan PhilOSOPhiCal QUarterly aristotelian vein, that essence is "the very being of any thing, whereby it is, what it is."14 he is only half right. essence is indeed the very being of a thing. to go on to assert that it is in virtue of ("whereby") its essence that a thing is what it is implies that an essence is something distinct from that thing, a thing that makes the latter be what it is. yet there can be no such thing.15 the account is also incompatible with the positions of the two foremost defenders of an ontological-rather than a modal16-essentialism in contemporary metaphysics. Kit Fine reifies the essence of a thing, identifying it with the real definition of that thing, to wit, the set of propositions true in virtue of it.17 looking past the oddness of identifying the being of a thing with a set (and with what is propositional and, hence, representational), Fine is led to do so by rejecting the identification of "the "being" of [a thing], its being what it is, with its existence."18 he argues for this distinction in this way: "in one respect, existence is too weak; for there is more to what an object [i.e., thing] is than its mere existence. in another respect, existence is too strong; for what an object is, its nature, need not include existence as a part."19 the first claim indicates the presumption that the "mere existence" of a thing must be supplemented in order for that thing to be what it is. this is just to presume that a thing is made to be what it is by some other thing and, hence, that its being what it is is explicable in terms of that thing. however, as i have argued, there can be no such thing. Moreover, if a thing just is a natured entity, there is not anything more to its existence than what it is. the second part of Fine's argument provides no reason to distinguish a thing's being what it is from its existence, for one can simply acknowledge that many natured entities can cease to exist. this has the benefit of not requiring the reification of "existence" itself, as Fine's position does (given that existence is regarded as a part). the underlying problem here is an impoverished notion of being, one on which the existence of a "thing" needs to be supplemented in order for that thing to be what it is. it is ultimately such a notion that leads to the expectation that individuation and unity and, more generally, what a thing is are amenable to explanation. One sees the same problem in the work of e.J. lowe. lowe endorses a serious essentialism according to which "although all entities have essences, essences themselves should never be thought of as further entities."20 Despite this unequivocal statement of his position, lowe seems to reify essences, driven to do so by his explicit endorsement of the tenet that essence precedes existence.21 if the essence of a thing precedes in an ontological sense (and lowe is clear that this is the relevant sense) the existence of that thing, the two must be distinct, and so its essence must be something in addition to its existence. the essence is, presumably, the thing that supplements the mere existence of a thing thereby making it be what it is. it is, however, just this problematic account of a thing-with its doomed explanatory expectations-that is precluded by the account of a thing as a natured entity. the impoverished notion of being that undermines the essentialism of Fine and lowe is a corollary of the assumption that what a thing is (or its individuation) is explicable. this assumption-and, consequently, the problematic account of a thing-is a constitutive feature of any version of hylomorphism. hylomorphism just is the doctrine according to which a distinguishable, even if inseparable, part of anything (in the purview of the doctrine) is a form, something that accounts for what that thing is. But, again, there can be no such thing. therefore, not only is the motivation for holding hylomorphism misguided-the doctrine cannot solve the explanatory problems it is supposed to-the ontology it requires is untenable. there are neither forms, things that make others be what APQ 56_3 text.indd 296 7/2/19 12:18 PM eaCh iS FUnDaMental / 297 they are, nor wan "things" that exist yet need to be made what they are. Conclusion: each thing is Fundamental this ontology of things as natured entities is revealed by examining explanation and discerning its means and bounds. the consequences of the ontology are farreaching, as it yields a correlative account of the structure in reality, one that precludes several views popular in contemporary discussions of metaphysics. By "structure" i do not mean a "primitive" feature of the world, as does theodore Sider,22 nor a variety of thing, each instance of which orders by "mak[ing] available positions or places for other objects, [i.e., things] to occupy," as does Kathrin Koslicki.23 rather, i take the structure in reality to be all the things there are standing in the relations they do. this structure, inclusive of all relations, comprises the ontological bases of any explicable phenomenon. the structure indicated by natured entities is broadly aristotelian in that it includes necessary relations whose provenance is things in themselves, as opposed to, say, the conceptual or linguistic capacities of conscious beings or their activities. these relations are necessary-and essential-because they arise exclusively from what their relata are and, as observed above, no thing can be other than what it is. Since neither the existence nor individuation of a thing, nor what anything is is explicable in terms of any other thing, each thing in this structure is both ontologically and explanatorily basic. each is, then, in this sense fundamental. Given this fundamentality, each makes a unique and ineliminable contribution to the structure in the world. there is no "ontological free lunch," in David armstrong's sense and, pace David Wiggins, each thing is indeed something "over and above" any other.24 therefore, there are no wan existents, derivative "things" that are ontologically or explanatorily less than others; fundamentality is not relative. this account of structure contravenes all familiar ones in contemporary discussions of metaphysics, for each of these takes for granted one or more "building relation"25-for example, composition, constitution, grounding, realization, microbasing, emergence, etc.-whereby one thing builds up or generates or constructs or gives rise to or is gotten out of another. in some cases, these building metaphors are elaborated in ontological terms, so that the very being of a thing is "latent" in and explicable in terms of another;26 in other cases, it is just what a thing is that is supposed to be explicable in terms of other things. either way, there can be no such explanatory relations among things, and so there is not the hierarchical structure to which such would give rise. it does not follow from there being no building relations that each thing is simple or that the structure in the world is not elaborate. assuming there are familiar concrete objects, there are fundamental things with parts. there is, then, composition-some things compose others-though, nota bene, a whole is not made to be by what it is composed of; it just is a complex thing, a thing with parts. a "flat" account of structure is not only consistent with complexity, it is consistent with (ontological) dependence. indeed, each natured entity is dependent on many things, in that given what it is, it must exist with those others. a thing might have to exist with a specific other thing (in which case the former is essentially rigidly dependent on the latter) or it might have to exist with a certain kind of thing, though any instance of that kind will do (in which case that thing is essentially generically dependent on instances of that kind).27 although some things might not be ontologically dependent in a given sense, there is no thing that is not ontologically dependent in some sense or other. a wholly ontologically independent thing, a "thing" that can exist in the absence APQ 56_3 text.indd 297 7/2/19 12:18 PM 298 / aMeriCan PhilOSOPhiCal QUarterly of any other-including every kind, every attribute, every mode-is incompatible with being natured and, thus, with existing at all. nevertheless, in no case is anything made to be the very thing it is or made to be what it is via a relation of dependence (thus, pace lowe, there is no identitydependence). So, the fundamentality of each thing does not rule out composition or ontological dependence. it does, however, show that even when these relations are asymmetric, there is no priority. What composes is not more real, nor does it have even an explanatory privilege over what is composed. likewise, for what is ontologically dependent; it is no less real, nor does it have any less explanatory privilege than that on which it depends. in these cases, as in all others, there are simply things in relation(s). Of course, with any relation, asymmetric or not, one can call one of its relata "prior" to the other, but this would be just a label backed with no real ontological and, hence, explanatory weight. hierarchical accounts of the structure in reality, ones on which some things are supposed to be genuinely prior to others, arise from many sources. there is the Democritean tradition, with ancient versions and familiar "modern scientific" guises, on which atoms- or physical fundamentalia du jour-are the bases that account for the very being or ways of being of all else. there is the hegemonic humean tradition on which basic whatnots, the correlates of sensory impressions, serve as the ontological and explanatory basis of all else, and the closely related Kantian tradition on which minds are the privileged things that serve as an explanatory basis for the existence or nature of other things and the constraints among them. hylomorphism and aristotelianism more generally are regarded as competitors to these other traditions, providing a quite different account of what exists and the order in reality, one that accommodates, in a more satisfying way, familiar concrete objects and the necessary connections among them. however, hylomorphism, no less than the other traditions, is committed to there being wan existents: "things" that exist though their very being or natures are to be accounted for in terms of other things. Forms play the privileged, ordering role on the hylomorphist's account of the structure in reality, with everything else being what it is only derivatively. What the preceding discussion demonstrates, though, is that privileging some things does not take seriously enough what it is to be. Since nothing can explain the existence or individuation of a thing or a thing's being what it is, there is no distinction between the mere existence of a thing and its being the very thing it is or what it is. to be is to be natured and, hence, to be fundamental. hylomorphism, like any other hierarchical account of structure, does not recognize the ubiquity of fundamentality, and so should be rejected on the same grounds as they. University of California, Irvine nOteS i would like to express my gratitude to Johannes Brandl and Christopher Gauker for discussion of the contents of this paper, and to yuval avnur, nathan Ballantyne, Daniel Korman, Jonathan Schaffer and tuomas tahko for very helpful written comments on a draft of it. i presented an early version of the paper at the Xii annual estonian Philosophy Conference in tallinn. i would like to thank my audience there, especially riin Sirkel, for their questions and comments. Paul hovda was the commentator on this paper when presented at the 2017 inland northwest Philosophy Conference (Metaphysics on the Mountain 2). i very much appreciate Paul's incisive and helpful comments, which enabled me to improve APQ 56_3 text.indd 298 7/2/19 12:18 PM eaCh iS FUnDaMental / 299 a crucial argument herein. i would also like to thank the other participants at the 2017 inland northwest Philosophy conference for helpful discussion, as well as those present at my colloquium at the Department of Philosophy at California State University, San Bernardino (especially Matthew Davidson and tony roy). John Greco provided invaluable editorial assistance, for which i am deeply grateful. i am also grateful for the comments of two anonymous referees from this journal. these comments (one set in particular) prompted elaboration at key points in my discussion and, i believe, made the paper better. i wrote this paper while a lise Meitner Fellow at the University of Salzburg, so i thank the FWF (austrian Science Fund) for its generous support (project number: M 1881G24). 1. For one account, see Witt (2003), (1987). 2. there are different notions of individuation. there is the metaphysical notion pertinent here and an epistemic one. individuation in the latter sense is a cognitive achievement of a conscious agent, one that occurs when that agent can discriminate via perception or thought a given thing among others. 3. See, for example, Jaworski (2014); Koslicki (2008), (2006); Johnston (2006); and Fine (1999). 4. For a classic account of explanation along these lines, see ruben (1990, especially Chapter 7). See, as well, Kim (1994, pp. 67–68). 5. if a and b are related Rly internally, in the sense that if a and b both exist, they must be so related, it might be plausible to deny that there is a distinct thing, R, that relates them. in what follows, i set aside the issue of whether the explanatory relation, R, is internal or external. Maintaining that there is no R because a and b are related (Rly) internally would just require changing the expression of the forthcoming arguments without affecting their conclusions. 6. See, for example, Fine (2012) and rosen (2010). 7. See the citations in note 3 above. 8. See van inwagen (1990). 9. For interpretations roughly along these lines see Marmodoro (2013) and Witt (1987). 10. Pace Donald Baxter and others who maintain that composition is identity. See Baxter (1988) and Cotnoir and Baxter (2014). 11. Pace Bliss, since the existence of a thing cannot be explained by another, there cannot be an infinite regress of a thing whose existence is explained by another, whose existence is explained by another thing, whose existence is explained by yet another, etc. See Bliss (2013, p. 414). in her paper, Bliss is attempting to present reasons for rejecting certain arguments for the view that there are fundamental entities, to wit, arguments that involve an infinite regress. My argument that each thing is fundamental is not one of these. Bliss seems to assume that the presence of fundamental entities must be accompanied by a hierarchical view of the structure in reality. as becomes clear in the concluding section, one can accept the former and yet reject the latter. 12. no thing is sustained in its being or otherwise made to be by some other thing. hence, the existence of a thing per se cannot be explained. nevertheless, one can explain how a given thing came to be. Coming to be is a temporal phenomenon, one that involves a thing in relation to some moment(s). the coming to be of a thing is, therefore, not a thing itself; it is a structural phenomenon. to explain how some thing came to be is to account for the existence of that thing at some moment (at which it need not have existed) in terms of other things and their interactions. if one seeks an explanation of the coming to be simpliciter of a thing-why it exists at all, rather than why it exists relative to a given moment-one seems to be overlooking the crucial temporal element in the phenomenon of coming to be. insofar as i understand the sort of explanation being sought, then, it seems to be foreclosed by the argument in the text against the explicability of the very existence of a thing. 13. For a different route to the same account of what a thing is, see my "What is a thing?". APQ 56_3 text.indd 299 7/2/19 12:18 PM 300 / aMeriCan PhilOSOPhiCal QUarterly 14. locke (1689, iii, iii, 15). 15. according to locke, the real essence of a familiar concrete object is its "particular internal constitution." it is this internal constitution that is supposed to ground an explanation of that object's having its definitive observable features and, hence, its being what it is. See locke (1689, ii, XXiii, 3). See lowe (2008, p. 38). 16. Modal essentialism is an approach to understanding the constraints on the being of a thing in terms of features that that thing must have. this is the sort of view made familiar by the work of Saul Kripke and hilary Putnam. Ontological essentialism is an approach to understanding the constraints on the being of a thing in terms of the very existence of that thing. Obviously, it is the latter that is adopted here. For the shortcomings of the modal approach see lowe (2008) and Fine (1995), (1994). 17. Fine (1995, p. 275). 18. 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