Despite huge efforts towards understanding the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pathogenesis, little is known about the long‐term consequences of the disease. Here, we critically review existing literature about oncogenesis as a potential long‐term effect of SARS‐CoV‐2 infection. Like other viral infections, SARS‐CoV‐2 may promote cancer onset by inhibiting tumor suppressor genes. We conclude that, although unlikely, such hypothesis cannot be excluded a priori and we delineate an experimental approach to address it. Also see the video abstract here: (...) https://youtu.be/TBUTDSLR7vY. (shrink)

The subject of Labelled Non-Classical Logics is the development and investigation of a framework for the modular and uniform presentation and implementation of non-classical logics, in particular modal and relevance logics. Logics are presented as labelled deduction systems, which are proved to be sound and complete with respect to the corresponding Kripke-style semantics. We investigate the proof theory of our systems, and show them to possess structural properties such as normalization and the subformula property, which we exploit not only to (...) establish advantages and limitations of our approach with respect to related ones, but also to give, by means of a substructural analysis, a new proof-theoretic method for investigating decidability and complexity of (some of) the logics we consider. All of our deduction systems have been implemented in the generic theorem prover Isabelle, thus providing a simple and natural environment for interactive proof development. Labelled Non-Classical Logics is essential reading for researchers and practitioners interested in the theory and applications of non-classical logics. (shrink)

Los géneros literarios que los críticos han utilizado para calificar la obra de Virginia Woolf, _Orlando_, publicada en 1928, incluyen: la alegoría religiosa, la fábula, la novela policíaca, literatura de doppelgänger, cuentos diabólicos escoceses o la novela gótica. Todavía se discute si es un relato de ciencia ficción. Sin embargo, el tema principal es la identidad sexual del protagonista, quien cruza un “tiempo sin tiempo” y transforma su sexo y sexualidad a lo largo del recorrido de su alma. Este, es (...) un claro rechace a la estructura de las novelas victorianas, en las cuales dominan los personajes masculinos y escasean los femeninos. Orlando nace hombre para luego, con el pasar de los siglos – desde 1600, últimos años de la reina Isabel I, hasta el siglo XX, en el contexto político real de Inglaterra, el de las sufragistas, cuando se da su transformación en mujer y sobre todo en escritora. Pese a lo apenas mencionado, esta novela no es sexista. Unos de sus fines principales es exponer las necesidades de una dama de la época isabelina, los tropiezos masculinos y femeninos de la sociedad victoriana y los obstáculos inherentes a las obsesiones del yo, en que el lenguaje es determinante para la marcación de épocas. Según Virginia, la diferencia sexual viene dada por la educación, pero no pretende fomentar la dualidad hombre-mujer, sino redefinir la feminidad y proclamar a la vez que una mente debe ser andrógina. (shrink)

Sets are central to mathematics and its foundations, but what are they? In this book Luca Incurvati provides a detailed examination of all the major conceptions of set and discusses their virtues and shortcomings, as well as introducing the fundamentals of the alternative set theories with which these conceptions are associated. He shows that the conceptual landscape includes not only the naïve and iterative conceptions but also the limitation of size conception, the definite conception, the stratified conception and the (...) graph conception. In addition, he presents a novel, minimalist account of the iterative conception which does not require the existence of a relation of metaphysical dependence between a set and its members. His book will be of interest to researchers and advanced students in logic and the philosophy of mathematics. (shrink)

In this paper, we develop an impure somatic theory of emotion, according to which emotions are constituted by the integration of bodily perceptions with representations of external objects, events, or states of affairs. We put forward our theory by contrasting it with Prinz's pure somatic theory, according to which emotions are entirely constituted by bodily perceptions. After illustrating Prinz's theory and discussing the evidence in its favor, we show that it is beset by serious problems—i.e., it gets the neural correlates (...) of emotion wrong, it isn't able to distinguish emotions from bodily perceptions that aren't emotions, it cannot account for emotions being directed towards particular objects, and it mischaracterizes emotion phenomenology. We argue that our theory accounts for the empirical evidence considered by Prinz and solves the problems faced by his theory. In particular, we maintain that our theory gives a unified and principled account of the relation between emotions and bodily perceptions, the intentionality of emotions, and emotion phenomenology. (shrink)

Constitutivism argues that the source of the categorical force of the norms of rationality and morality lies in the constitutive features of agency. A systematic failure to be guided by these norms would amount to a loss or lack of agency. Since we cannot but be agents, we cannot but be unconditionally guided by these norms. The constitutivist strategy has been challenged by David Enoch. He argues that our participation in agency is optional and thus cannot be a source of (...) categorical demands. In this paper, I defend the viability of constitutivism by showing that agency is indeed a special ‘inescapable’ enterprise. Agency has the largest jurisdiction, and it is closed under rational assessment. This inescapability does not exempt constitutivism from raising the question whether agents have reason to be agents, but this question has to be taken up within agency. If this question is answered affirmatively, then—I argue—the criteria of practical correctness are self-ratifying in a non-circular way. This is sufficient to show the viability of the constitutivist strategy. Whether agents have conclusive reasons to be agents, however, is a matter to be addressed in the terms of particular versions of constitutivism. (shrink)

According to Jim Pryor’s dogmatism, when you have an experience with content p, you often have prima facie justification for believing p that doesn’t rest on your independent justification for believing any proposition. Although dogmatism has an intuitive appeal and seems to have an antisceptical bite, it has been targeted by various objections. This paper principally aims to answer the objections by Roger White according to which dogmatism is inconsistent with the Bayesian account of how evidence affects our rational credences. (...) If this were true, the rational acceptability of dogmatism would be seriously questionable. I respond that these objections don’t get off the ground because they assume that our experiences and our introspective beliefs that we have experiences have the same evidential force, whereas the dogmatist is uncommitted to this assumption. I also consider the question whether dogmatism has an antisceptical bite. I suggest that the answer turns on whether or not the Bayesian can determine the priors of hypotheses and conjectures on the grounds of their extra-empirical virtues. If the Bayesian can do so, the thesis that dogmatism has an antisceptical bite is probably false. (shrink)

A 'self-refutation argument' is any argument which aims at showing that a certain thesis is self-refuting. This study was the first book-length treatment of ancient self-refutation and provides a unified account of what is distinctive in the ancient approach to the self-refutation argument, on the basis of close philological, logical and historical analysis of a variety of sources. It examines the logic, force and prospects of this original style of argumentation within the context of ancient philosophical debates, dispelling various misconceptions (...) concerning its nature and purpose and elucidating some important differences which exist both within the ancient approach to self-refutation and between that approach, as a whole, and some modern counterparts of it. In providing a comprehensive account of ancient self-refutation, the book advances our understanding of influential and debated texts and arguments from philosophers like Democritus, Plato, Aristotle, Epicurus, the Stoics, the Academic sceptics, the Pyrrhonists and Augustine. (shrink)

In this paper, I discuss whether there are genuinely *diachronic* constraints of practical rationality, that is, pressures on combinations of practical attitudes over time, which are not reducible to mere synchronic rational pressures. Michael Bratman has recently argued that there is at least one such diachronic rational constraint that governs the stability of intentions over time. *Pace* Bratman, I argue that there are no genuinely diachronic constraints on intentions that meet the stringent desiderata set by him. But I show that (...) there are at least two synchronic rational constraints with distinctive and important, although only indirect, diachronic dimensions. Neither of them, however, supports the practical conservatism in the face of normative underdetermination that, according to Bratman, is part and parcel of the diachronic rationality of intention stability. (shrink)

We discuss a well-known puzzle about the lexicalization of logical operators in natural language, in particular connectives and quantifiers. Of the many logically possible operators, only few appear in the lexicon of natural languages: the connectives in English, for example, are conjunction _and_, disjunction _or_, and negated disjunction _nor_; the lexical quantifiers are _all, some_ and _no_. The logically possible nand (negated conjunction) and Nall (negated universal) are not expressed by lexical entries in English, nor in any natural language. Moreover, (...) the lexicalized operators are all upward or downward monotone, an observation known as the Monotonicity Universal. We propose a logical explanation of lexical gaps and of the Monotonicity Universal, based on the dynamic behaviour of connectives and quantifiers. We define update potentials for logical operators as procedures to modify the context, under the assumption that an update by \( \phi \) depends on the logical form of \( \phi \) and on the speech act performed: assertion or rejection. We conjecture that the adequacy of update potentials determines the limits of lexicalizability for logical operators in natural language. Finally, we show that on this framework the Monotonicity Universal follows from the logical properties of the updates that correspond to each operator. (shrink)

The paper introduces and formally defines a functional concept of a measuring system, on this basis characterizing the measurement as an evaluation performed by means of a calibrated measuring system. The distinction between exact and uncertain measurement is formalized in terms of the properties of the traceability chain joining the measuring system to the primary standard. The consequence is drawn that uncertain measurements lose the property of relation-preservation, on which the very concept of measurement is founded according to the representational (...) viewpoint. Finally, from the analysis of the inter-relations between calibration and measurement the fundamental reasons of the claimed objectivity and intersubjectivity of measurement are highlighted, a valuable epistemological result to characterize measurement as a particular kind of evaluation. (shrink)

Experiences like pains, pleasures, and emotions have affective phenomenal character: they feel pleasant or unpleasant. Imperativism proposes to explain affective phenomenal character by appeal to imperative content, a kind of intentional content that directs rather than describes. We argue that imperativism is on the right track, but has been developed in the wrong way. There are two varieties of imperativism on the market: first-order and higher-order. We show that neither is successful, and offer in their place a new theory: reflexive (...) imperativism. Our proposal is that an experience P feels pleasant in virtue of being constituted by a Command with reflexive imperative content, while an experience U feels unpleasant in virtue of being constituted by a Command with reflexive imperative content : More of P!Less of U! If you need a slogan: experiences have affective phenomenal character in virtue of commanding us Get more of me! Get less of me! (shrink)

It is often argued that future-directed decisions are effective at shaping our future conduct because they give rise, at the time of action, to a decisive reason to act as originally decided. In this paper, I argue that standard accounts of decision-based reasons are unsatisfactory. For they focus either on tie-breaking scenarios or cases of self-directed distal manipulation. I argue that future-directed decisions are better understood as tools for the non-manipulative, intrapersonal division of deliberative labor over time. A future-directed decision (...) to ϕ gives rise to a defeasible exclusionary reason to ϕ. This reason is grounded on the default authority that is normally granted to one’s prior self as an “expert” deliberator. I argue that this kind of exclusionary reason is the only one that can account for the effectiveness of future-directed decisions at shaping our diachronic agency without violating our autonomy over time. (shrink)

Given the common assumption that measurement plays an important role in the foundation of science, the paper analyzes the possibility that Measurement Science, and therefore measurement itself, can be properly founded. The realist and the representational positions are analyzed at this regards: the conclusion, that such positions unavoidably lead to paradoxical situations, opens the discussion for a new epistemology of measurement, whose characteristics and interpretation are sketched here but are still largely matter of investigation.

In this paper, I will discuss the various ways in which intentions can be said to be conditional, with particular attention to the internal conditions on the intentions’ content. I will first consider what it takes to carry out a conditional intention. I will then discuss how the distinctive norms of intention apply to conditional intentions and whether conditional intentions are a weaker sort of commitments than the unconditional ones. This discussion will lead to the idea of what I call (...) the ‘deep structure’ of intentions. Roughly, this is the idea that the conditional nature of our intentions is only partially made explicit in the expressions we use to communicate our intentions and in the explicit form of our thinking about and reasoning with them. Most conditions that qualify our intentions are part of a deep functional structure that can be evinced by observing the actual psychological functioning of intentions and by considering the rational requirements that they engage. I will argue that the deep structure of intentions is characteristically conditional. Genuinely unconditional intentions are only limiting instances of conditional intentions and their contribution to agency can only be understood in light of this fact. I will conclude by showing that the characteristic conditional structure of intentions is intimately related to distinctive features of human agency, especially to its unity over time. (shrink)

Both sustainability and identity are said to be paradoxical issues in organizations. In this study we look at the paradoxes of corporate sustainability at the individual level by studying the identity work of those managers who hold sustainability-dedicated roles in organizations. Analysing 26 interviews with sustainability managers, we identify three main tensions affecting their identity construction process: the business versus values oriented, the organizational insider versus outsider and the short-term versus long-term focused identity work tensions. When dealing with these tensions, (...) some interviewees express a paradoxical perspective in attempting to accept and maintain the two poles of each of them simultaneously. It emerges in particular that metaphorical reasoning can be used by sustainability managers in varied ways to cope with the tensions of identity work. We read these findings in light of the existing literature on the relation between paradoxes and identity work, highlighting and discussing their implications for both research and practice. (shrink)

Many classically valid meta-inferences fail in a standard supervaluationist framework. This allegedly prevents supervaluationism from offering an account of good deductive reasoning. We provide a proof system for supervaluationist logic which includes supervaluationistically acceptable versions of the classical meta-inferences. The proof system emerges naturally by thinking of truth as licensing assertion, falsity as licensing negative assertion and lack of truth-value as licensing rejection and weak assertion. Moreover, the proof system respects well-known criteria for the admissibility of inference rules. Thus, supervaluationists (...) can provide an account of good deductive reasoning. Our proof system moreover brings to light how one can revise the standard supervaluationist framework to make room for higher-order vagueness. We prove that the resulting logic is sound and complete with respect to the consequence relation that preserves truth in a model of the non-normal modal logic _NT_. Finally, we extend our approach to a first-order setting and show that supervaluationism can treat vagueness in the same way at every order. The failure of conditional proof and other meta-inferences is a crucial ingredient in this treatment and hence should be embraced, not lamented. (shrink)

One type of argument to sceptical paradox proceeds by making a case that a certain kind of metaphysically “heavyweight or “cornerstone” proposition is beyond all possible evidence and hence may not be known or justifiably believed. Crispin Wright has argued that we can concede that our acceptance of these propositions is evidentially risky and still remain rationally entitled to those of our ordinary knowledge claims that are seemingly threatened by that concession. A problem for Wright’s proposal is the so-called Leaching (...) worry: if we are merely rationally entitled to accept the cornerstones without evidence, how can we achieve evidence-based knowledge of the multitude of quotidian propositions that we think we know, which require the cornerstones to be true? This paper presents a rigorous, novel explication of this worry within a Bayesian framework, and offers the Entitlement theorist two distinct responses. (shrink)

We present an inferentialist account of the epistemic modal operator might. Our starting point is the bilateralist programme. A bilateralist explains the operator not in terms of the speech act of rejection ; we explain the operator might in terms of weak assertion, a speech act whose existence we argue for on the basis of linguistic evidence. We show that our account of might provides a solution to certain well-known puzzles about the semantics of modal vocabulary whilst retaining classical logic. (...) This demonstrates that an inferentialist approach to meaning can be successfully extended beyond the core logical constants. (shrink)

Bus bunching is ostensibly regarded as a detrimental phenomenon in bus systems. We study a bus loop with two bus stops, one regular bus stop and one spike bus stop, where bunched buses can outperform staggered buses. The spike bus stop models a bus stop connected to a train or metro service, where passengers arrive in groups at periodic intervals. We introduce the configuration of synchronised bunched buses, where bunched buses wait for the spike in demand. For a wide range (...) of parameters, synchronised bunched buses outperform perfectly staggered buses in terms of minimising the waiting time of commuters. We present an analytical formulation of the average waiting time in the case of bunched buses, synchronised bunched buses, and perfectly staggered buses with the consideration of different passenger demands, number of buses, and bus capacity. We demonstrate the validity of our analytical results through an agent-based simulation of the bus loop system. (shrink)

In set theory, a maximality principle is a principle that asserts some maximality property of the universe of sets or some part thereof. Set theorists have formulated a variety of maximality principles in order to settle statements left undecided by current standard set theory. In addition, philosophers of mathematics have explored maximality principles whilst attempting to prove categoricity theorems for set theory or providing criteria for selecting foundational theories. This article reviews recent work concerned with the formulation, investigation and justification (...) of maximality principles. (shrink)

According to the iterative conception of set, sets can be arranged in a cumulative hierarchy divided into levels. But why should we think this to be the case? The standard answer in the philosophical literature is that sets are somehow constituted by their members. In the first part of the paper, I present a number of problems for this answer, paying special attention to the view that sets are metaphysically dependent upon their members. In the second part of the paper, (...) I outline a different approach, which circumvents these problems by dispensing with the priority or dependence relation altogether. Along the way, I show how this approach enables the mathematical structuralist to defuse an objection recently raised against her view. (shrink)

Crispin Wright has given an explanation of how a first time warrant can fall short of transmitting across a known entailment. Formal epistemologists have struggled to turn Wright’s informal explanation into cogent Bayesian reasoning. In this paper, I analyse two Bayesian models of Wright’s account respectively proposed by Samir Okasha and Jake Chandler. I argue that both formalizations are unsatisfactory for different reasons, and I lay down a third Bayesian model that appears to me to capture the valid kernel of (...) Wright’s explanation. After this, I consider a recent development in Wright’s account of transmission failure. Wright suggests that his condition sufficient for transmission failure of first time warrant also suffices for transmission failure of supplementary warrant. I propose an interpretation of Wright’s suggestion that shield it from objections. I then lay down a fourth Bayesian framework that provides a simplified model of the unified explanation of transmission failure envisaged by Wright. (shrink)

We present a natural deduction system for dual-intuitionistic logic. Its distinctive feature is that it is a single-premise multiple-conclusions system. Its relationships with the natural deduction systems for intuitionistic and classical logic are discussed.

The non-well-founded set theories described by Aczel (1988) have received attention from category theorists and computer scientists, but have been largely ignored by philosophers. At the root of this neglect might lie the impression that these theories do not embody a conception of set, but are rather of mere technical interest. This paper attempts to dispel this impression. I present a conception of set which may be taken as lying behind a non-well-founded set theory. I argue that the axiom AFA (...) is justified on the conception, which provides, contra Rieger (Mind 109:241–253, 2000), a rationale for restricting attention to the system based on this axiom. By making use of formal and informal considerations, I then make a case that most of the other axioms of this system are also justified on the conception. I conclude by commenting on the significance of the conception for the debate about the justification of the Axiom of Foundation. (shrink)

Deflationists about truth hold that the function of the truth predicate is to enable us to make certain assertions we could not otherwise make. Pragmatists claim that the utility of negation lies in its role in registering incompatibility. The pragmatist insight about negation has been successfully incorporated into bilateral theories of content, which take the meaning of negation to be inferentially explained in terms of the speech act of rejection. We implement the deflationist insight in a bilateral theory by taking (...) the meaning of the truth predicate to be explained by its inferential relation to assertion. We combine this account of the meaning of the truth predicate with a new diagnosis of the Liar Paradox: its derivation requires the truth rules to preserve evidence, but these rules only preserve commitment. The result is a novel inferential deflationist theory of truth, which solves the Liar Paradox in a principled manner. We end by showing that our theory and simple extensions thereof have the resources to axiomatize the internal logic of several supervaluational hierarchies, including Cantini’s. This solves open problems of Halbach (2011) and Horsten (2011). (shrink)

_ Source: _Page Count 19 In this paper, we tackle the contribution that history of science can make to the _problem of rule-choice_, i.e., the choice from among competing methodological rules. Taking our cue from Larry Laudan’s writings, we extensively discuss what we call _historicist naturalism_, i.e., the view that history of science plays a pivotal role in the justification of rules, since it is one source of the evidence required to settle methodological controversies. As we illustrate, there are cases (...) of rule-choice that depend on conceptual considerations alone, and in which history of science does not factor. Moreover, there are cases in which methodological change is prompted – and explained – by empirical information that is not historical in nature: as suggested by what we call _scientific naturalism_, the justification of methodological choices comes from our knowledge of the structure of the world, as expressed by our currently accepted scientific theories. As we argue, due to its backward-looking character, historicist naturalism does not satisfactorily deal with the case of newly introduced rules, for which no evidence concerning their past performance is available. In sum, we conclude, the contribution that history of science can make to rule-choice is more modest than Laudan suggests. (shrink)

Coherentism in epistemology has long suffered from lack of formal and quantitative explication of the notion of coherence. One might hope that probabilistic accounts of coherence such as those proposed by Lewis, Shogenji, Olsson, Fitelson, and Bovens and Hartmann will finally help solve this problem. This paper shows, however, that those accounts have a serious common problem: the problem of belief individuation. The coherence degree that each of the accounts assigns to an information set (or the verdict it gives as (...) to whether the set is coherent tout court) depends on how beliefs (or propositions) that represent the set are individuated. Indeed, logically equivalent belief sets that represent the same information set can be given drastically different degrees of coherence. This feature clashes with our natural and reasonable expectation that the coherence degree of a belief set does not change unless the believer adds essentially new information to the set or drops old information from it; or, to put it simply, that the believer cannot raise or lower the degree of coherence by purely logical reasoning. None of the accounts in question can adequately deal with coherence once logical inferences get into the picture. Toward the end of the paper, another notion of coherence that takes into account not only the contents but also the origins (or sources) of the relevant beliefs is considered. It is argued that this notion of coherence is of dubious significance, and that it does not help solve the problem of belief individuation. (shrink)

The paper introduces what is deemed as the general epistemological problem of measurement: what characterizes measurement with respect to generic evaluation? It also analyzes the fundamental positions that have been maintained about this issue, thus presenting some sketches for a conceptual history of measurement. This characterization, in which three distinct standpoints are recognized, corresponding to a metaphysical, an anti-metaphysical, and relativistic period, allows us to introduce and briefly discuss some general issues on the current epistemological status of measurement science.

Lexical innovations (e.g., zero-derivations coined on the fly by a speaker) seem to bear semantic content. Yet, such expressions cannot bear semantic content as a function of the conventions of meaning in force in the language, since they are not part of its lexicon. This is in tension with the commonplace view that the semantic content of lexical expressions is constituted by linguistic conventions. The conventionalist has two immediate ways out of the tension. The first is to preserve the conventionalist (...) assumption and deny that lexical innovations bear semantic content. The second is to dynamicize the conventionalist assumption, that is, argue that presentations of unattested expressions trigger an augmentation of the standing semantic resources of the language and instantiate content as a result of this underlying update. Building on a comparison with the production of novel onomatopoeic words, iconic pseudowords and pro-speech gestures, the paper argues that the issue is best addressed by suspending the conventionalist assumption, and describes the metasemantic implications of the claim. (shrink)

In this work, we present some traits of the socio-political and economic thought of Giuseppe Toniolo, who lived in Italy at the turn of the XIX and XX century, with special reference to the contribution that the Italian economist and sociologist gave to the definition and implementation of the principle of subsidiarity and to the ethical foundation of economic science. After outlining the definition of the subsidiarity principle in the first paragraph, we sketch the historical background in which Toniolo lived (...) and operated. We then focus on the ethical factor and on the concept of subsidiary State emerging from Toniolo’s writings. Finally, we present some of the main elements of Toniolo’s legacy with reference to the current economic and socio-political debate. (shrink)

According to constitutivism, we can justify the authority of aims and norms on the ground that they are inescapable. Constitutivist views divide between ambitious and modest ones. According to ambitious constitutivism, the inescapability of aims grounds their unconditional authority, whereas according to modest constitutivism, the inescapability of aims only grounds their conditional authority. Either way, both forms of constitutivism share the assumption that inescapability grounds authority, which in turn presupposes that at the foundation of normativity we find aims and norms (...) that can be evaluated as having or lacking authority. In this paper I shall defend a form of constitutivism that rejects this assumption. According to this view, which I shall call Hinge Constitutivism, at the foundation of epistemic normativity we find an aim, the truth-aim, that is altogether beyond the evaluation in terms of the ordinary notion of authority. Moreover, I shall argue that to aim at truth is a condition of possibility for justifying the authority of any other aims or norms. In this sense, to aim at truth is a hinge of deliberation. (shrink)

We develop a novel solution to the negation version of the Frege-Geach problem by taking up recent insights from the bilateral programme in logic. Bilateralists derive the meaning of negation from a primitive *B-type* inconsistency involving the attitudes of assent and dissent. Some may demand an explanation of this inconsistency in simpler terms, but we argue that bilateralism’s assumptions are no less explanatory than those of *A-type* semantics that only require a single primitive attitude, but must stipulate inconsistency elsewhere. Based (...) on these insights, we develop a version of B-type expressivism called *inferential expressivism*. This is a novel semantic framework that characterises meanings by inferential roles that define which *attitudes* one can *infer* from the use of terms. We apply this framework to normative vocabulary, thereby solving the Frege-Geach problem generally and comprehensively. Our account moreover includes a semantics for epistemic modals, thereby also explaining normative terms under epistemic modals. (shrink)

I focus on a key argument for global external world scepticism resting on the underdetermination thesis: the argument according to which we cannot know any proposition about our physical environment because sense evidence for it equally justifies some sceptical alternative (e.g. the Cartesian demon conjecture). I contend that the underdetermination argument can go through only if the controversial thesis that conceivability is per se a source of evidence for metaphysical possibility is true. I also suggest a reason to doubt that (...) conceivability is per se a source of evidence for metaphysical possibility, and thus to doubt the underdetermination argument. (shrink)