Otávio Bueno

This work examines a number of arguments to the effect that quantification requires identity of the objects that are quantified over; the arguments concern the domain of quantification, the range of quantifiers, the collapse of the existential and the universal quantifiers, and the intelligibility of quantification. The central role of identity in quantification is identified in each case. Also considered is quantification in non-classical contexts, and it is argued that even in logics and set theories that supposedly do not demand identity for quantification, identity is still presupposed. Along the way, some recent challenges to this overall approach are considered.

An examination of the grounds of logical necessity is offered by taking its lead from Barry Stroud’s challenge to the possibility of articulating satisfactorily any such grounds in full generality. The intelligibility of logical aliens is also considered, and different conceptions of such aliens, some more radical in their treatment of the issue than others, are examined as well. Logical aliens are beings whose thinking goes beyond the limits of thought, presumably with a logic different from our own. I argue that logical aliens are either something straightforward and unproblematic or something we cannot recognize as logical. In either case, there are ways of accommodating such aliens despite the fact that the search for grounds of logical necessity is ultimately misguided.

In this paper, we examine two conceptions of the application of logic and assess their comparative merits. The first is a platonist monist conception that characterizes the logical consequence relation as an abstract relation among propositions. We argue that this proposal, which insists on logic’s topic neutrality, accommodates very well the objectivity of logic. From this perspective, there are no constraints on particular topics. As a result, we have the universality that allows us to go through a wide scope of contexts where logic is applied. In contrast, a non-platonist pluralist conception is examined, and it characterizes the variety of logical consequence relations as concrete, context-dependent in particular cases, and topic-dependent. As will become clear, this conception is particularly well suited to make room for the applications of logic. We conclude that, in order to solve the ontological debate about logic, we need to go beyond its applications.

Skepticism and naturalism bear important connections with one another. Do they conflict or are they different sides of the same coin? In this paper, by considering the ways in which Sextus and Hume have examined these issues, I offer a Pyrrhonian response to Penelope Maddy's attempt to reject skepticism within the form of naturalism that she calls “second philosophy” (Maddy, 2007, 2017) and to Timothy Williamson's attempt to avoid skepticism from emerging within his knowledge‐first approach (Williamson, 2000). Some lessons about Pyrrhonism result.

Pyrrhonism involves the inability to defend claims about the unobservable world, or, more generally, about what is really going on beyond the phenomena. As a result, the Pyrrhonist is not engaged in developing a philosophical doctrine, at least in the sense of defending a view about the underlying features of reality. The issue then arises as to whether the Pyrrhonist also has something positive to say about our knowledge of the world, while still keeping Pyrrhonism. In this paper, I develop a positive neo-Pyrrhonist attitude, indicating that we can use this attitude to make sense of important aspects of science and empirical knowledge. To do that, I explore the connection between this revived form of Pyrrhonism and contemporary versions of empiricism, in particular constructive empiricism. Although constructive empiricism is not a form of skepticism, there are important elements in common between constructive empiricism and Pyrrhonism. The resulting form of Pyrrhonism suggests that there is something right about the original stance articulated by Sextus Empiricus, and that suitably formulated it provides an insightful approach to think about empirical knowledge.

In this paper, I discuss two aspects of top-down causation in George Ellis’s compelling account of this complex concept. I first examine whether mathematical structures can enter into any causal relations, and argue that it is unclear that they can. I highlight instead the role played by the interpretation of mathematical theories in the context of applied mathematics. Second, I consider the role played by top-down causation in measurement, especially in quantum mechanics but also elsewhere, and identify the importance of the observer in this context. I am in large agreement with Ellis’s overall message, but we may understand certain details a bit differently. I articulate the message within a broadly empiricist setting.

What sort of evidence can confer the strongest support to a hypothesis? A natural answer is that the evidence entails the hypothesis. Roush claims that the likelihood ratio measure of degree of incremental support can deliver this intuitively natural result, and regards it as unifying “[the] account of induction and deduction in the only way that makes sense”. In this paper, we highlight a difficulty in the treatment of this case, and question the great significance that is attached to this measure and its alleged capacity to accommodate the logicality requirement. We contrast the likelihood ratio measure with other measures, and argue that problems still emerge in light of tensions with plausible requirements for confirmation measures more generally.

In this paper, I examine critically whether there is a role for consciousness in quantum theory. First, I consider von Neumann’s (Mathematical foundations of quantum mechanics (The English translation, by Robert T. Beyer, of the original German edition was first published in 1955). Princeton University Press, Princeton, 1932) alleged introduction of consciousness in the interpretation of (non-relativistic) quantum mechanics, and conclude that consciousness plays no role in it. I then examine Wigner’s (Symmetries and reflections: Scientific essays (Reprint from the 1967 edition published by Indiana University Press). Ox Bow Press, Woodbridge, 1979) views on the matter, identifying him, rather than von Neumann, as the leading proponent of the view that favors a prominent role for consciousness (see also Freire O, Jr: The quantum dissidents: Rebuilding the foundations of quantum mechanics (1950–1990). Springer, Dordrecht, 2015). I then question the aptness of such a role by advancing a minimalist interpretation of London and Bauer’s (The theory of observation in quantum mechanics. In: Wheeler JA, Zurek WH (eds) Quantum theory and measurement. Princeton University Press, Princeton, pp 217–259. (The original work was published in French in 1939), 1939/1983) theory of observation in quantum mechanics, which has been taken as a key source of arguments in support for consciousness (particularly in connection with phenomenology, see French S: Stud Hist Philos Mod Phys 33:467–491, 2002), and conclude with a dilemma against views that identify a place for consciousness in quantum theory.

In this paper, I reconstruct a technique originally formulated by Hermann Weyl to accommodate, in the foundations of quantum mechanics, aggregates of quantum particles despite these particles’ apparent lack of identity. I defend the importance of this technique and provide a slight variant of Weyl’s original formulation by avoiding altogether the use of set theory. I then offer formulations of individuals and non-individuals, inspired by considerations that Weyl made in the context of his theory of aggregates, and examine the status of non-individuals with regard to debates about realism. I conclude that there is still much to be learned from careful study of Weyl’s work.

In this paper we examine theoretical utility arguments in metaphysics. While philosophers claim a procedural continuity with science when using such arguments, we argue that examining famous instances from the history of science expose their fundamental flaws. We find that arguments from theoretical utility invoke considerations that are not truth conducive and that justifications for claims that a theory possesses theoretical virtues often assume the truth of the theory such virtues are supposed to support. We conclude that theoretical utility arguments provide no epistemic grounds for metaphysical inquiry.

The structure of natural languages is usually studied from three major different but interconnected points of view: syntax, semantics, and pragmatics. If we consider that the main purpose of natural languages is communication, we should consider another dimension for languages, which deals with the influence of internal states of communicating individuals on meanings. Such a dimension we refer to as internalism. Within this context, internalism cannot be confused with psycholinguistics, in the same way pragmatics cannot be confused with sociolinguistics. In particular, we argue, language is tied to its systematic use. This view leads us to a non-realist perspective on linguistics. We analyze the role of natural languages into dialogues, by comparing our proposal to the dialogical approach to logic, which considers a dialogue as a game. Within our approach, there is no way to guarantee that two parties involved in a dialogue are playing the same game, due to unavoidable differences in their respective internal states. Another contribution of this paper is to argue that semantics plays a more fundamental role than syntax in the cognitive acquisition of languages.

In this work, we focus on a very specific case study: assuming that quantum theories deal with “particles” of some kind, what kind of entity can such particles be? One possible answer, the one we shall examine here, is that they are not the usual kind of object found in daily life: individuals. Rather, we follow a suggestion by Erwin Schrödinger, according to which quantum mechanics poses a revolutionary kind of entity: non-individuals. While physics, as a scientific field, is not concerned with whether entities posited by a specific physical theory are individuals or not, answering this question is part of the quest for a better understanding of physical reality. Here lies, in large measure, the relevance of ontology.

Quantifier variance faces a number of difficulties. In this paper we first formulate the view as holding that the meanings of the quantifiers may vary, and that languages using different quantifiers may be charitably translated into each other. We then object to the view on the basis of four claims: (i) quantifiers cannot vary their meaning extensionally by changing the domain of quantification; (ii) quantifiers cannot vary their meaning intensionally without collapsing into logical pluralism; (iii) quantifier variance is not an ontological doctrine; (iv) quantifier variance is not compatible with charitable translation and as such is internally inconsistent. In light of these troubles, we recommend the dissolution of quantifier variance and suggest that the view be laid to rest.

Scientific pluralism is the view according to which there is a plurality of scientific domains and of scientific theories, and these theories are empirically adequate relative to their own respective domains. Scientific monism is the view according to which there is a single domain to which all scientific theories apply. How are these views impacted by the presence of inconsistent scientific theories? There are consistency-preservation strategies and inconsistency-toleration strategies. Among the former, two prominent strategies can be articulated: Compartmentalization and Information restriction. Among the inconsistency-toleration strategies, we have: Paraconsistent compartmentalization and Dialetheism. In this paper, I critically assess the adequacy of each of these four views.

Identity is arguably one of the most fundamental concepts in metaphysics. There are several reasons why this is the case: Identity is presupposed in every conceptual system: without identity, it is unclear that any conceptual system can be formulated. Identity is required to characterize an individual: nothing can be an individual unless it has well-specified identity conditions. Identity cannot be defined: even in systems that allegedly have the resources to define identity. Identity is required for quantification: the intelligibility of quantification presupposes the identity of the objects that are quantified over. These are only four considerations in support of identity's fundamental role. In this paper, I examine and defend them. I then examine a challenge that has been raised against identity's fundamentality: one from the metaphysics of physics—based on a significant interpretation of non-relativist quantum mechanics—according to which certain quantum particles lack identity conditions. After responding to this challenge, I consider the nature of the commitment to identity, and argue that it turns out to be very minimal. In fact, a very deflationary form of metaphysics can accommodate it. In arguing that identity is fundamental, one need not overstep the boundaries of even a very minimal empiricist metaphysics. Or so I argue.

In his defense of a coherence theory of truth and knowledge, Donald Davidson insists that (i) we must take the objects of a belief to be the causes of that belief, and (ii) given the nature of beliefs, most of our be-liefs are veridical. As result, a response to skepticism is provided. If most of our beliefs turn out to be true, global skepticism is ultimately incoher-ent. In this paper, I argue that, despite the many attractions that a co-herence theory has, a response to skepticism is not among them. After distinguishing three forms of skepticism (global skepticism, Pyrrhonian skepticism and lottery skepticism), I argue that none of them is affected by Davidson’s strategy.

Based on da Costa's and French's notions of partial structures and pragmatic truth, this paper examines two possible characterizations of the concept of empirical adequacy, one depending on the notion of partial isomorphism, the other on the hierarchy of partial models of phenomena, and both compatible with an empiricist view. These formulations can then be employed to illuminate certain aspects of scientific practice.An empirical theory must single out a specific part of the world, establish reference to that part, and say—by way of contingent, substantial claim about the world—that its models fit that. Now, how exactly can this be done? Bas C. van Fraassen.

Hartry Field has recently examined the question whether our logical and mathematical concepts are referentially indeterminate. In his view, (1) certain logical notions, such as second-order quantification, are indeterminate, but (2) important mathematical notions, such as the notion of finiteness, are not (they are determinate). In this paper, I assess Field's analysis, and argue that claims (1) and (2) turn out to be inconsistent. After all, given that the notion of finiteness can only be adequately characterized in pure secondorder logic, if Field is right in claiming that second-order quantification is indeterminate (see (1)), it follows that finiteness is also indeterminate (contrary to (2)). After arguing that Field is committed to these claims, I provide a diagnosis of why this inconsistency emerged, and I suggest an alternative, consistent picture of the relationship between logical and mathematical indeterminacy.

Current versions of nominalism in the philosophy of mathematics have the benefit of avoiding commitment to the existence of mathematical objects. But this comes with the cost of not taking mathematical theories literally. Jody Azzouni's _Deflating Existential Consequence_ has recently challenged this conclusion by formulating a nominalist view that lacks this cost. In this paper, we argue that, as it stands, Azzouni's proposal does not yet succeed. It faces a dilemma to the effect that either the view is not nominalist or it fails to take mathematics literally. After presenting the dilemma, we suggest a possible solution for the nominalist.

Structuralism and factualism are two significant metaphysical views about the fundamental traits of the world. Structuralism characterizes these traits in terms of structures, which, in turn, are either taken as primitive or accounted for mathematically in ways that may not settle what they are metaphysically (French, The structure of the world: metaphysics and representation. Oxford University Press, Oxford, 2014). Factualism takes fundamental traits of the world to be facts, which, in turn, either have constituents (Cumpa, A materialist criterion of fundamentality. Am Philos Q 51:319–324, 2014; Factualism and the scientific image. Int J Philos Stud 26:669–678, 2018) or do not, in which case their ultimate nature is similarly left open. These are importantly different accounts of the fundamental, which despite some surface similarities, turn out to be incompatible with one another. Can the debate between them be settled? Is there a fact of the matter to achieve that? In this paper, I argue that it is unclear how to offer conclusive answers to these questions, and advance an alternative, deflationary way of making sense of the debate.

Mona Simion and Christoph Kelp (2020) have recently challenged the traditional conceptual engineering project. They defend a reorientation of this project that moves away from correcting conceptual shortcomings and emphasizes conceptual innovation instead. Central to their proposal is the role played by etiological functions. The present paper argues that this approach leaves them without a specific mechanism for conceptual innovation. It then proposes one such mechanism, which operates independently of functions, by identifying the crucial role of conceptual refinement. After developing the refinement‐based approach, it illustrates how this approach works by considering instances of refined conceptual change from mathematics and logic as well as the sciences, and argues that the approach avoids the challenges faced by the function‐based view.

Some dialetheists have claimed that one of the central advantages of their approach to the Paradoxes of Self-Reference is that they are able to offer a unified solution to structurally similar paradoxes that arise in the semantic and set-theoretic realms (Priest in Mind 103:25–34, [12] and Beyond the limits of thought. Clarendon Press, Oxford, [16]). They argue that since the structures of all of these paradoxes conform with the Inclosure Schema (IS), the Principle of Uniform Solution (PUS) dictates that we should solve them all the same way. But the dialetheist’s approach to PUS collapses when it comes to the Curry Paradox, to which any solution based on dialetheism seems inapplicable. We show that a particular version of a ‘paracomplete’ theory (inspired by Field in Saving truth from paradox. Oxford University Press, Oxford, [8]) has available to it a way of avoiding these problems that the dialetheist cannot mirror without losing Modus Ponens. JC Beall has suggested a way of minimizing this loss, but Beall’s strategy runs up against a further difficulty about the PUS. This one involves the Irrationalist’s Paradox. We conclude with a dilemma: The dialetheist can either reject the principles that are used to accommodate ordinary reasoning when Modus Ponens or Disjunctive Syllogism fail, and thus live without the ability to mimic these inferences, or they can sacrifice the Principle of Uniform Solution by solving an extremely Liar-like semantic paradox in a way that has nothing to do with their solution to the Liar and Curry’s Paradox. In either case, the prospects for a plausible and truly uniform dialetheic solution to the paradoxes of self-reference are grim.