We show that a standard axiomatization of mereology is equivalent to the condition that a topological space is discrete, and consequently, any model of general extensional mereology is indistinguishable from a model of set theory. We generalize these results to the Cartesian closed category of convergence spaces.

Many mereological propositions are true contingently, so we are entitled to ask why they are true. One frequently given type of answer to such questions evokes truth-makers, that is, entities in virtue of whose existence the propositions in question are true. However, even without endorsing the extreme view that all contingent propositions have truth-makers, it turns out to be puzzlingly hard to provide intuitively convincing candidate truth-makers for even a core class of basic mereological propositions. Part of the problem is (...) that the relation of part to whole is ontologically intimate in a way reminiscent of identity. Such intimacy bespeaks a formal or internal relation, which typically requires no truth-makers beyond its terms. But truth-makers are held to necessitate their truths, so whence the contingency when A is part of B but need not be, or B need not have A as part? This paper addresses and attempts to disentangle the conundrum. (shrink)

Mereological nihilists typically employ a paraphrase strategy in order to mitigate the apparent absurdity of their denial of the existence of composite objects. I argue here that the nihilist's paraphrase strategy is incomplete, because no schema for generating nihilistically acceptable paraphrases of sentences concerning material constitution has ever been given. Nor can an adequate schema be arrived at by generalising things that nihilists have already said. I fill this lacuna in the nihilist's account by developing and defending a novel paraphrase (...) schema that makes essential reference to the determinable‐determinate relation that holds between arrangement‐properties instantiated by the simples. (shrink)

Mereological nihilism is the view that no objects have proper parts. Despite how counter‐intuitive it is, it is taken quite seriously, largely because it solves a number of puzzles in the metaphysics of material objects – or so its proponents claim. In this article, I show that for every puzzle that mereological nihilism solves, there is a similar puzzle that (a) it doesn’t solve, and (b) every other solution to the original puzzle does solve. Since the solutions to the new (...) puzzles apply just as well to the old puzzles, the old puzzles provide no motivation to be a mereological nihilist. (shrink)

The debate about the ontological innocence of mereology has generally been framed as a debate about the plausibility of Universal Fusion. Ontologically loaded fusions must be more than the sum of their parts, and this seems to violate parsimony if fusion is universal. Less attention has been paid to the question of what sort of emergence mereological fusions must exhibit if they are irreducible to their parts. The philosophy of science literature provides several models of such strong emergence. Examining (...) those models suggests that the difficulty with emergent fusions has at least as much to do with extensionality as it does with Universal Fusion. Some accounts of emergence fail to ensure irreducibility when combined with extensional mereologies. The most promising model for the strong emergence of ontologically loaded fusions fails to validate Anti-Symmetry, which naturally leads to failures of extensionality. These results suggest that the focus on Universal Fusion may have been misplaced. (shrink)

Mereology as an art of composing complex concepts out of simpler parts is suited well to the task of reasoning under uncertainty: whereas it is most often difficult to ascertain whether a given thing is an element of a concept, it is possible to decide with belief degree close to certainty that the class of things is an ingredient of an other class, which is sufficient for carrying out the reasoning whose conclusions are taken as true under given conditions. (...) We present in this work a scheme for reasoning based on mereology in which mereology in the classical sense is fuzzified in analogy to the concept fuzzification in the sense of L. A. Zadeh. In this process, mereology becomes rough mereology. (shrink)

Mereological nihilism (henceforth just "nihilism") is the thesis that composition never occurs. Nihilism has often been defended on the basis of its theoretical simplicity, including its ontological simplicity and its ideological simplicity (roughly, nihilism's ability to do without primitive mereological predicates). In this paper I defend nihilism on the basis of the theoretical unification conferred by nihilism, which is, roughly, nihilism's capacity to allow us to take fewer phenomena as brute and inexplicable. This represents a respect in which nihilism enjoys (...) greater theoretical simplicity than its rivals which has not yet been explored, and which is immune to many of the objections which have been leveled against previous arguments for nihilism from nihilism's theoretical simplicity. Composition as identity might be thought to confer a similar degree of theoretical unification as nihilism. I end the paper by arguing that this is not the case. (shrink)

Mereological nihilism is the thesis that composite objects—objects with proper parts—do not exist. Nihilists generally paraphrase talk of composite objects F into talk of there being “xs arranged F-wise” . Recently several philosophers have argued that nihilism is defective insofar as nihilists are either unable to say what they mean by such phrases as “there are xs arranged F-wise,” or that nihilists are unable to employ such phrases without incurring significant costs, perhaps even undermining one of the chief motivations for (...) nihilism. In this paper I defend nihilism against these objections. A key theme of the paper is this: if nihilists need to employ such phrases as “there are xs arranged F-wise,” non-nihilists will need to do so as well. Accordingly, any costs incurred by the nihilist when she employs such phrases will be shared by everyone else. What’s more, such phrases are intelligible when employed by the nihilist, as well as when they are employed by the non-nihilist, insofar as analyses of such phrases will not essentially involve mereological concepts incompatible with nihilism. (shrink)

Mereological principles are sometimes used to support general claims about the structure and arrangement of objects in the world. I focus initially on one such mereological principle, the weak supplementation principle (WSP). It is not obvious that (WSP) is prescribed by ordinary thinking about parthood. Further, (WSP) is not needed for a fairly strong formal characterization of the part–whole relation. For these reasons, some arguments relying on (WSP) might be countered by simply denying (WSP). I argue more generally that there (...) is no reason to assume that one core mereology functions as a common basis for all plausible metaphysical theories. (shrink)

When do the folk think that mereological composition occurs? Many metaphysicians have wanted a view of composition that fits with folk intuitions, and yet there has been little agreement about what the folk intuit. We aim to put the tools of experimental philosophy to constructive use. Our studies suggest that folk mereology is teleological: people tend to intuit that composition occurs when the result serves a purpose. We thus conclude that metaphysicians should dismiss folk intuitions, as tied into a (...) benighted teleological view of nature. (shrink)

Is a whole something more than the sum of its parts? Are there things composed of the same parts? If you divide an object into parts, and divide those parts into smaller parts, will this process ever come to an end? Can something lose parts or gain new ones without ceasing to be the thing it is? Does any multitude of things (including disparate things such as you, this book, and the tail of a cat) compose a whole of some (...) sort? Questions such as these have occupied us for at least as long as philosophy has existed. They define the field that has come to be known as mereology-the study of all relations of part to whole and of part to part within a whole-and have deep and far-reaching ramifications in metaphysics as well as in logic, the foundations of mathematics, the philosophy of language, the philosophy of science, and beyond. In Mereology, A. J. Cotnoir and Achille C. Varzi have compiled decades of advanced research into a comprehensive, up-to-date, and formally rigorous picture. The early chapters cover the more classical aspects of mereology; the rest of the book deals with variants and extensions. Whether you are an established professional philosopher, an interested student, or a newcomer, inside you will find all the tools you need to join this ever-evolving field of inquiry and theorize about all things mereological. (shrink)

Mereological nihilism is the thesis that composition never occurs. Sider has defended nihilism on the basis of its relative ideological simplicity. In this paper I develop the argument from ideological simplicity, and defend it from some recent objections. Along the way I discuss the best way to formulate nihilism, what it means for a theory to exhibit lesser or greater degrees of ideological simplicity, the relationship between the parthood relation and the identity relation, and the notion that we should judge (...) the ideological simplicity of competing theories on the basis of the kinds of ideological commitments required by those theories. (shrink)

Mereology, the theory of parts and wholes, is sometimes used as a framework for categorisation because it is regarded as ontologically innocent in the sense that the mereological fusion of some entities is nothing over and above the entities. In this paper it is argued that an adequate answer to the question of whether the thesis of the ontological innocence of mereology holds relies crucially on the underlying theory of reference. It is then shown that upholding the thesis (...) comes at high costs, viz. at the cost of a quite strong logical background theory or at paradoxical ways of predicating and counting. (shrink)

Mereological nihilism is the view that there are no composite objects; everything in existence is mereologically simple. The view is subject to a number of difficulties, one of which concerns what I call the problem of emergence. Very briefly, the problem is that nihilism seems to be incompatible with emergent properties; it seems to rule out their very possibility. This is a problem because there are good independent reasons to believe that emergent properties are possible. This paper provides a solution (...) to the problem. I will show that nihilism and emergence are perfectly compatible, providing one accepts a novel understanding of how objects can instantiate properties: what I call irreducibly collective instantiation. (shrink)

Two mereological theories are presented based on a primitive apartness relation along with binary relations of mereological excess and weak excess, respectively. It is shown that both theories are acceptable from the standpoint of constructive reasoning while remaining faithful to the spirit of classical mereology. The two theories are then compared and assessed with regard to their extensional import.

Parthood and composition are everywhere. The leg of a table is part of the table, the word "Christmas" is part of the sentence "I wish you a merry Christmas", the 13th century is part of the Middle Ages. The Netherlands, Belgium, and Luxembourg compose Benelux, the body of a deer is composed of a huge number of cells, the Middle Ages are composed of the Early Middle Ages, High Middle Ages, and Late Middle Ages. Is there really a general theory (...) covering every instance of parthood and composition? Is classical mereology this general theory? Are its seemingly counter-intuitive features serious defects? -/- Mereology: A Philosophical Introduction addresses the multifaceted and lively philosophical debates surrounding these questions, and defends the idea that classical mereology is indeed the general and exhaustive theory of parthood and composition in the domain of concrete entities. -/- Several examples of parthood and composition, involving entities of different kinds, are scrutinised in depth. Incidentally, mereology is shown to interact in a surprising way with metaontology. Presenting a well-organized and comprehensive discussion of parthood and related notions, Mereology: A Philosophical Introduction contributes to a better understanding of a subject central to contemporary metaphysics. (shrink)

Mereological nihilists hold that composition never occurs, so that nothing is ever a proper part of anything else. Substance dualists generally hold that we are each identical with an immaterial soul. In this paper, I argue that every popular objection to substance dualism has a parallel objection to composition. This thesis has some interesting implications. First, many of those who reject composition, but accept substance dualism, or who reject substance dualism and accept composition, have some explaining to do. Secondly, one (...) popular objection to mereological nihilism, one which contends that mereological nihilism is objectionable insofar as it is incompatible with the existence of people, is untenable. (shrink)

This paper explores the mereology of structural universals, using the structural richness of a non-classical mereology without unique fusions. The paper focuses on a problem posed by David Lewis, who using the example of methane, and assuming classical mereology, argues against any purely mereological theory of structural universals. The problem is that being a methane molecule would have to contain being a hydrogen atom four times over, but mereology does not have the concept of the same (...) part occurring several times. This paper takes up the challenge by providing mereological analysis of three operations sufficient for a theory of structural universals: Reflexive binding, i.e. identifying two of the places of a universal; Existential binding, i.e. the language-independent correlate of an existential quantification; and Conjunction. (shrink)

I argue that mereological nihilism fails because it cannot answer the special arrangement question: when is it true that the xs are arranged F-wise? I suggest that the answers given in the literature fail and that the obvious responses that could be made look to undermine the motivations for adopting nihilism in the first place.

Classical mereology (CM) is usually taken to be formulated in a tenseless language, and is therefore associated with a four-dimensionalist metaphysics. This paper presents three ways one might integrate the core idea of flat plenitude, i.e., that every suitable condition or property has exactly one mereological fusion, with a tensed logical setting. All require a revised notion of mereological fusion. The candidates differ over how they conceive parthood to interact with existence in time, which connects to the distinction between (...) endurance and perdurance. Similar issues arise for the integration of mereology with modality, and much of our discussion applies to this project as well. (shrink)

Zombies are unconscious objects with conscious physical micro-duplicates. If zombies are possible then physicalism is false. It has been argued that zombies are possible if conceivable for an agent with ideal rationality. At any rate, they are possible only if so conceivable. This essay uses a mereological constraint to highlight the fine-grained differences between actually conscious physical objects and certain of their actually consciousness-incapable proper parts. These mereological considerations form the basis of an argument by dilemma that zombies are inconceivable. (...) Either an arbitrary actually conscious object might have had simpler consciousness-capable parts than it in fact has, or not. The affirmative horn leads to a version of panpsychism that is inconsistent with the ideal conceivability of zombies. The negative horn rules out zombies as incoherent. The upshot is a new reason to deny the conceivability of zombies. (shrink)

Do mereological fusions have their parts necessarily? None of the axioms of non-modal formulations of classical mereology appear to speak directly to this question. And yet a great many philosophers who take the part-whole relation to be governed by classical mereology seem to assume that they do. In addition to this, many philosophers who make allowance for the part-whole relation to obtain merely contingently between a part and a mereological fusion tend to depart from non-modal formulations of classical (...) mereology at least when it comes to the axiom of Unique Fusion, which states that no two different mereological fusions ever fuse exactly the same objects. This is no coincidence. There are reasons of principle why one’s adherence to classical mereology should exert some pull towards the view that mereological fusions have their parts necessarily. There is, however, no direct route from the combination of classical mereology and propositional modal logic to the hypothesis that the part-whole relation obtains necessarily between a part and a mereological fusion. In order to bridge between a modal formulation of classical mereology and the hypothesis that fusions have their parts necessarily, one needs to strengthen the axiom of Unrestricted Fusion in a way that is agreeable to many philosophers on both sides of the debate. (shrink)

Mereological nihilism is the philosophical position that there are no items that have parts. If there are no items with parts then the only items that exist are partless fundamental particles, such as the true atoms (also called philosophical atoms) theorized to exist by some ancient philosophers, some contemporary physicists, and some contemporary philosophers. With several novel arguments I show that mereological nihilism is the correct theory of reality. I will also discuss strong similarities that mereological nihilism has with empirical (...) results in quantum physics. And I will discuss how mereological nihilism vindicates a few other theories, such as a very specific theory of philosophical atomism, which I will call quantum abstract atomism. I will show that mereological nihilism also is an interpretation of quantum mechanics that avoids the problems of other interpretations, such as the widely known, metaphysically generated, quantum paradoxes of quantum physics, which ironically are typically accepted as facts about reality. I will also show why it is very surprising that mereological nihilism is not a widely held theory, and not the premier theory in philosophy. (shrink)

Lewis famously argued that mereology is ontologically innocent. Many who have considered this claim believe he was mistaken. Mereology is not innocent, because its acceptance entails the acceptance of sums, new objects that were not previously part of one’s ontology. This argument, the argument from ontological parsimony, has two versions: a qualitative and a quantitative one. I argue that the defender of mereology can neutralize both arguments by holding that, given mereology, a commitment to the parts (...) of an object is not an extra ontological commitment, made in addition to the commitment to the object; and that if the parts of an object are ‘ontologically innocent’, then sums cannot fail to be innocent either. (shrink)

The paper explores the proof theory of non-wellfounded mereology with binary fusions and provides a cut-free sequent calculus equivalent to the standard axiomatic system.

It is often assumed that indeterminacy in mereological relations—in particular, indeterminacy in which collections of objects have fusions—leads immediately to indeterminacy in what objects there are in the world. This assumption is generally taken as a reason for rejecting mereological vagueness. The purpose of this paper is to examine the link between mereological vagueness and existential vagueness. I hope to show that the connection between the two forms of vagueness is not nearly so clear-cut as has been supposed.

Classical mereology is a formal theory of the part-whole relation, essentially involving a notion of mereological fusion, or sum. There are various different definitions of fusion in the literature, and various axiomatizations for classical mereology. Though the equivalence of the definitions of fusion is provable from axiom sets, the definitions are not logically equivalent, and, hence, are not inter-changeable when laying down the axioms. We examine the relations between the main definitions of fusion and correct some technical errors (...) in prominent discussions of the axiomatization of mereology. We show the equivalence of four different ways to axiomatize classical mereology, using three different notions of fusion. We also clarify the connection between classical mereology and complete Boolean algebra by giving two "neutral" axiom sets which can be supplemented by one or the other of two simple axioms to yield the full theories; one of these uses a notion of "strong complement" that helps explicate the connections between the theories. (shrink)

Damiano Costa has recently offered a novel mereological definition of endurantism based on the idea that for an object to be wholly present at a time is for it to be a whole at that time. In this paper, I argue that Costa’s is not a definition of endurantism, since the idea that every object is a whole at every time it exists can be accepted by endurantists and perdurantists alike.

Core principles of mereology have been questioned by appealing to time travel scenarios. This paper questions the methodology of employing time travel scenarios to argue against mereology. We show some time travel scenarios are structurally equivalent to more standard ones not involving time travel; and that the three main theories about persistence through time can each solve both the time travel scenario as well as the structurally similar classical scenario. Time travel scenarios that are not similar to more (...) standard arguments are instead problematic because they are open to different, incompatible interpretations. We conclude that compared to the classical arguments against mereological principles, time travel scenarios do not add anything new. (shrink)

This paper offers a critical reconstruction of the motivations that led to the development of mereology as we know it today, along with a brief description of some problems that define current research in the field.

The philosophical discussion of emergence is often focused on properties of ‘wholes’ that are evaluated as emergent with respect to the properties of ‘parts’. Downward causation is, consequently, evaluated as some kind of causal influence of whole properties over parts properties. Yet, several important cases in scientific practice seem to be pursuing hypotheses of parts properties emerging from wholes properties, inverting the instinctive association of emergence with wholes. Furthermore, some areas of reflection which are very important for emergence, e.g., the (...) philosophy of consciousness, do not allow mapping properties onto part-whole organizations. The conceptual puzzle is solved by constructing a framework that disentangles the mereological dimension from the superventional dimension. By liberalizing the spatio-temporal allocation of emergent properties, the proposed dual framework could better capture the way in which emergence and downward causation are addressed in scientific practice. (shrink)

We will present an elementary theory in which we can speak of mereological sets composed of distributive classes. Besides the concept of a distributive class and the membership relation , it will possess the notion of a mereological set and the relation of being a mereological part. In this theory we will interpret Morse’s elementary set theory (cf. Morse [11]). We will show that our theory has a model, if only Morse’s theory has one.

By the classical mereology I mean a theory of mereological structures in the sense of [10]. In [7] I proved that the class of these structures is not elementarily axiomatizable. In this paper a new version of this result is presented, which according to my knowledge is the first such presentation in English. A relation of this result to a certain Hsing-chien Tsai’s theorem from [13] is emphasized.

This articles explores the mereological foundation of truthmaker semantics. Building upon Kit Fine’s abstract theory of part in [16], we engage in an exploration of the mereological assumptions that determine the construction of truthmaker semantics. Our approach yields semantics for a diverse range of logics, including substructural logics such as the associative Lambek calculus, as well as the logics of analytic containment. Furthermore, we elucidate the philosophical implications that arise from this pioneering approach.

Paul (Noûs 36:578–596, 2002; Noûs 40:623–659, 2006, The Handbook of Mereology, forthcoming) has argued for a bundle theory of objects that analyzes the bundling relation between properties and objects in terms of parthood relations. In this paper I argue that any mereological bundle theory with the explanatory power of Paul’s theory will entail the principle of the identity of indiscernibles (PII). This is problematic, since similar bundle theories seem to fall to Max Black’s two sphere counterexample to (PII). I (...) argue, however, that a fully developed mereological bundle theory provides a new way of interpreting Black’s two sphere universe that dispels the counterexample. I argue that this solution to Black’s puzzle is superior to other solutions on offer, and consequently that mereological bundle theory is an attractive ontological strategy for friends of (PII). (shrink)

McTaggart maintained that, without the kind of change which events undergo in passing from the future through the present into the past, how things are would be fundamentally different from how they appear. More particularly Without A-change there could be no change at all. Without any change there could be no time. Without A-change there could be no time.

Haecceities are non-qualitative properties for individuation but the current theories about haecceities are still to be much more explored. This paper aims to develop a “haecceity mereology” – that is, an ontological system that understands substances as mereological combinations of haecceities and qualitative properties. In this way, the view developed is an alternative to Paul’s : 578–96; 2006. “Coincidence as Overlap.” Noûs 40 : 623–59) mereological approach. Three rules are proposed: If S is a substance, then there is one (...) and only one haecceity which is S’s qualitative part; For all the fusions with the same haecceity, at most only one of those fusions is a substance; When all the relevant elements are abundant, every element must overlap at least one substance. This is the first ontology of haecceities in the recent literature and would be a model for systematic metaphysics. (shrink)

This article surveys the theory of the part relation (mereology), quantified modal logic, and Kripke and Putnam’s notion of natural kinds. It shows how the former two bear on the macroscopic understanding of the notions of substance and phase, which stands in contrast to the microphysical essentialism of Kripke and Putnam, and can be used to explicate Aristotle’s and the Stoic conceptions of mixture. The article concludes with some comments about the relevance of the issues raised by these ancient (...) theories to modern views of element, compound and mixture. (shrink)

In classical extensional mereology, composition is idempotent: if x is part of y, then the sum of x and y is identical to y. In this paper, I provide a systematic and coherent formal mereology for which idempotence fails. I first discuss a number of purported counterexamples to idempotence that have been put forward in the literature. I then discuss two recent attempts at sketching non-idempotent formal mereology due to Karen Bennett and Kit Fine. I argue that (...) these attempts are incomplete, however, and there are many open issues left unresolved. I then construct a class of models of a non-idempotent mereology using multiset theory, consider their algebraic structure, and show how these models can shed light on the open issues left from the previous approaches. (shrink)

According to Lewis, mereology is the general and exhaustive theory of ontological composition, and every contingent feature of the world supervenes upon some fundamental properties instantiated by minimal entities. A profound analogy can be drawn between these two basic contentions of his metaphysics, namely that both can be intended as a denial of emergentism. In this essay, we study the relationships between Humean supervenience and two philosophical spin-offs of mereological monism: the possibility of gunk and the thesis of composition (...) as identity. In a gunky scenario, there are no atoms and, thus, some criteria alternative to mereological atomicity must be introduced in order to identify the bearers of fundamental properties; this introduction creates a precedent, which renders the restriction of the additional criteria to gunky scenarios arbitrary. On the other hand, composition as identity either extends the principle of indiscernibility of identicals to composition or is forced to replace indiscernibility with a surrogate; both alternatives lead to the postulation of a symmetric kind of supervenience which, in contrast to Humean supervenience, does not countenance a privileged level. Both gunk and composition as identity, thus, display a tension with Humean supervenience. (shrink)

An overview of contemporary part-whole theories, with reference to both their axiomatic developments and their philosophical underpinnings.

This article motivates and develops a reductive account of the structure of certain physical quantities in terms of their mereology. That is, I argue that quantitative relations like "longer than" or "3.6-times the volume of" can be analyzed in terms of necessary constraints those quantities put on the mereological structure of their instances. The resulting account, I argue, is able to capture the intuition that these quantitative relations are intrinsic to the physical systems they’re called upon to describe and (...) explain. (shrink)

In his book, 'History as a Science and the System of the Sciences', Thomas Seebohm articulates the view that history can serve to mediate between the sciences of explanation and the sciences of interpretation, that is, between the natural sciences and the human sciences. Among other things, Seebohm analyzes history from a phenomenological perspective to reveal the material foundations of the historical human sciences in the lifeworld. As a preliminary to his analyses, Seebohm examines the formal and material presuppositions of (...) phenomenological epistemology, as well as the emergence of the human sciences and the traditional distinctions and divisions that are made between the natural and the human sciences. -/- As part of this examination, Seebohm devotes a section to discussing Husserl’s formal mereology because he understands that a reflective analysis of the foundations of the historical sciences requires a reflective analysis of the objects of the historical sciences, that is, of concrete organic wholes (i.e., social groups) and of their parts. Seebohm concludes that Husserl’s mereological ontology needs to be altered with regard to the historical sciences because the relations between organic wholes and their parts are not summative relations. Seebohm’s conclusion is relevant for the issue of the reducibility of organic wholes such as social groups to their parts and for the issue of the reducibility of the historical sciences to the lower-order sciences, that is, to the sciences concerned with lower-order ontologies. -/- In this paper, I propose to extend Seebohm’s conclusion to the ontology of chemical wholes as object of quantum chemistry and to argue that Husserl’s formal mereology is descriptively inadequate for this regional ontology as well. This may seem surprising at first, since the objects studied by quantum chemists are not organic wholes. However, my discussion of atoms and molecules as they are understood in quantum chemistry will show that Husserl’s classical summative and extensional mereology does not accurately capture the relations between chemical wholes and their parts. This conclusion is relevant for the question of the reducibility of chemical wholes to their parts and of the reducibility of chemistry to physics, issues that have been of central importance within the philosophy of chemistry for the past several decades. (shrink)

I propose a new theory of mereology based on a mereological reflection principle. Reflective mereology has natural fusion principles but also refutes certain principles of classical mereology such as Universal Fusion and Fusion Uniqueness. Moreover, reflective mereology avoids Uzquiano’s cardinality problem–the problem that classical mereology tends to clash with set theory when they both quantify over everything. In particular, assuming large cardinals, I construct a model of reflective mereology and second-order ZFCU with Limitation of (...) Size. In the model, classical mereology holds when the quantifiers are restricted to the urelements. (shrink)

When Aristotle introduces the perfect moods, he refers back to the dictum de omni et nullo, a semantic condition for universal affirmations and negations. There recently has been renewed interest in the question whether the dictum validates the assertoric syllogistic. I rehearse evidence that Aristotle provides a mereological semantics for universal affirmations and negations, and note that this semantics entails a nonstandard reading of the dictum, under which the dictum, in the presence of a minimal logical apparatus, indeed validates the (...) assertoric syllogistic. I argue that this mereological validation offers advantages over recent discussions in Morison, Malink, Ebert and Vlasits. (shrink)

Mereological Nominalism, as traditionally understood, states that properties are mereological wholes and that instantiation is mereological. Thus defined, this view faces a number of well-known issues, which make it virtually untenable. Recently, Effingham :160–185, 2020) has offered an alternative account of Mereological Nominalism, which intends to avoid these problems by accepting while rejecting. In this paper, we argue that this theory is not viable for two main reasons. First, it faces a threat of circularity. Second, the various non-mereological accounts of (...) instantiation envisioned by Effingham in order to replace seem inconsistent with. (shrink)

We suggest possible approaches to point-free geometry based on multi-valued logic. The idea is to assume as primitives the notion of a region together with suitable vague predicates whose meaning is geometrical in nature, e.g. ‘close’, ‘small’, ‘contained’. Accordingly, some first-order multi-valued theories are proposed. We show that, given a multi-valued model of one of these theories, by a suitable definition of point and distance we can construct a metrical space in a natural way. Taking into account that interesting metrical (...) approaches to geometry exist, this looks to be promising for a point-free foundation of the notion of space. We hope also that this way to face point-free geometry provides a tool to illustrate the passage from a naïve and ‘qualitative’ approach to geometry to the ‘quantitative’ approach of advanced science. (shrink)

How does Aristotle think about sentences like ‘Every x is y’ in the Prior Analytics? A recently popular answer conceives of these sentences as expressing a mereological relationship between x and y: the sentence is true just in case x is, in some sense, a part of y. I argue that the motivations for this interpretation have so far not been compelling. I provide a new justification for the mereological interpretation. First, I prove a very general algebraic soundness and completeness (...) result that unifies the most important soundness and completeness results to date. Then I argue that this result vindicates the mereological interpretation. In contrast to previous interpretations, this argument shows how Aristotle’s conception of predication in mereological terms can do important logical work. (shrink)