Logical paradoxes – like the Liar, Russell's, and the Sorites – are notorious. But in Paradoxes and Inconsistent Mathematics, it is argued that they are only the noisiest of many. Contradictions arise in the everyday, from the smallest points to the widest boundaries. In this book, Zach Weber uses “dialetheic paraconsistency” – a formal framework where some contradictions can be true without absurdity – as the basis for developing this idea rigorously, from mathematical foundations up. In doing so, Weber (...) directly addresses a longstanding open question: how much standard mathematics can paraconsistency capture? The guiding focus is on a more basic question, of why there are paradoxes. Details underscore a simple philosophical claim: that paradoxes are found in the ordinary, and that is what makes them so extraordinary. (shrink)

Hilbert’s program was an ambitious and wide-ranging project in the philosophy and foundations of mathematics. In order to “dispose of the foundational questions in mathematics once and for all,” Hilbert proposed a two-pronged approach in 1921: first, classical mathematics should be formalized in axiomatic systems; second, using only restricted, “finitary” means, one should give proofs of the consistency of these axiomatic systems. Although Gödel’s incompleteness theorems show that the program as originally conceived cannot be carried out, it had many partial (...) successes, and generated important advances in logical theory and metatheory, both at the time and since. The article discusses the historical background and development of Hilbert’s program, its philosophical underpinnings and consequences, and its subsequent development and influences since the 1930s. (shrink)

Logic has pride of place in mathematics and its 20th century offshoot, computer science. Modern symbolic logic was developed, in part, as a way to provide a formal framework for mathematics: Frege, Peano, Whitehead and Russell, as well as Hilbert developed systems of logic to formalize mathematics. These systems were meant to serve either as themselves foundational, or at least as formal analogs of mathematical reasoning amenable to mathematical study, e.g., in Hilbert’s consistency program. Similar efforts continue, but have been (...) expanded by the development of sophisticated methods to study the properties of such systems using proof and model theory. In parallel with this evolution of logical formalisms as tools for articulating mathematical theories (broadly speaking), much progress has been made in the quest for a mechanization of logical inference and the investigation of its theoretical limits, culminating recently in the development of new foundational frameworks for mathematics with sophisticated computer-assisted proof systems. In addition, logical formalisms developed by logicians in mathematical and philosophical contexts have proved immensely useful in describing theories and systems of interest to computer scientists, and to some degree, vice versa. Three examples of the influence of logic in computer science are automated reasoning, computer verification, and type systems for programming languages. (shrink)

I exploit parallel considerations in the philosophy of mind and metaethics to argue that the reasoning employed in an important argument for panpsychism overgeneralizes to support an analogous position in metaethics: panmoralism. Next, I raise a number of problems for panmoralism and thereby build a case for taking the metaethical parallel to be a reductio ad absurdum of the argument for panpsychism. Finally, I contrast panmoralism with a position recently defended by Einar Duenger Bohn and argue that the two suffer (...) from similar problems. I conclude by drawing some general lessons for panpsychism. (shrink)

The proof theory of many-valued systems has not been investigated to an extent comparable to the work done on axiomatizatbility of many-valued logics. Proof theory requires appropriate formalisms, such as sequent calculus, natural deduction, and tableaux for classical (and intuitionistic) logic. One particular method for systematically obtaining calculi for all finite-valued logics was invented independently by several researchers, with slight variations in design and presentation. The main aim of this report is to develop the proof theory of finite-valued first order (...) logics in a general way, and to present some of the more important results in this area. In Systems covered are the resolution calculus, sequent calculus, tableaux, and natural deduction. This report is actually a template, from which all results can be specialized to particular logics. (shrink)

Ng :255–285, 1995. https://doi.org/10.1007/bf00852469) models the evolutionary dynamics underlying the existence of suffering and enjoyment and concludes that there is likely to be more suffering than enjoyment in nature. In this paper, we find an error in Ng’s model that, when fixed, negates the original conclusion. Instead, the model offers only ambiguity as to whether suffering or enjoyment predominates in nature. We illustrate the dynamics around suffering and enjoyment with the most plausible parameters. In our illustration, we find surprising results: (...) the rate of failure to reproduce can improve or worsen average welfare depending on other characteristics of a species. Our illustration suggests that for organisms with more intense conscious experiences, the balance of enjoyment and suffering may lean more toward suffering. We offer some suggestions for empirical study of wild animal welfare. We conclude by noting that recent writings on wild animal welfare should be revised based on this correction to have a somewhat less pessimistic view of nature. (shrink)

Textbook on Gödel’s incompleteness theorems and computability theory, based on the Open Logic Project. Covers recursive function theory, arithmetization of syntax, the first and second incompleteness theorem, models of arithmetic, second-order logic, and the lambda calculus.

Prevailing opinion—defended by Jason Brennan and others—is that voting to change the outcome is irrational, since although the payoffs of tipping an election can be quite large, the probability of doing so is extraordinarily small. This paper argues that prevailing opinion is incorrect. Voting is shown to be rational so long as two conditions are satisfied: First, the average social benefit of electing the better candidate must be at least twice as great as the individual cost of voting, and second, (...) the chance of casting the decisive vote must be at least 1/N, where N stands for the number of citizens. It is argued that both of these conditions are often true in the real world. (shrink)

Methods available for the axiomatization of arbitrary finite-valued logics can be applied to obtain sound and complete intelim rules for all truth-functional connectives of classical logic including the Sheffer stroke and Peirce’s arrow. The restriction to a single conclusion in standard systems of natural deduction requires the introduction of additional rules to make the resulting systems complete; these rules are nevertheless still simple and correspond straightforwardly to the classical absurdity rule. Omitting these rules results in systems for intuitionistic versions of (...) the connectives in question. (shrink)

What should a person do when, through no fault of her own, she ends up believing a false moral theory? Some suggest that she should act against what the false theory recommends; others argue that she should follow her rationally held moral beliefs. While the former view better accords with intuitions about cases, the latter one seems to enjoy a critical advantage: It seems better able to render moral requirements ‘followable’ or ‘action-guiding.’ But this tempting thought proves difficult to justify. (...) Indeed, whether it can be justified turns out to depend importantly on the rational status of epistemic akrasia. Furthermore, it can be argued, from premises all parties to the moral ignorance debate should accept, that rational epistemic akrasia is possible. If the argument proves successful, it follows that a person should sometimes act against her rationally held moral convictions. (shrink)

I propose a novel metaphysical explanation of identity and distinctness facts called the Modal Proposal. According to the Modal Proposal, for each identity fact – that is, each fact of the form a=b – that fact is metaphysically explained by the fact that it is necessary that the entities involved are indiscernible, and for each distinctness fact –that is, each fact of the form a≠b – that fact is metaphysically explained by the fact that it is possible for the entities (...) involved to be discernible. I argue that the Modal Proposal has greater payoffs at less cost than any of its competitors. It gives simple, uniform, and intuitive explanations of identity and distinctness that conserve longstanding philosophical insights about identity that go back to Leibniz. It does this while making our fundamental base more parsimonious, determining whether controversial cases of identity or distinctness are possible, and expanding our understanding of these central philosophical relations. It does all this while avoiding controversial ontological commitments. (shrink)

There is a well-known moral quandary concerning how to account for the rightness or wrongness of acts that clearly contribute to some morally significant outcome – but which each seem too small, individually, to make any meaningful difference. One consequentialist-friendly response to this problem is to deny that there could ever be a case of this type. This paper pursues this general strategy, but in an unusual way. Existing arguments for the consequentialist-friendly position are sorites-style arguments. Such arguments imagine varying (...) a subject’s predicament bit by bit until it is clear that a relevant difference has been achieved. The arguments offered in this paper are structurally different, and do not rely on any sorites series. For this reason, they are not vulnerable to objections that have been leveled against the sorites-style arguments. (shrink)

The Curry-Howard isomorphism is a proof-theoretic result that establishes a connection between derivations in natural deduction and terms in typed lambda calculus. It is an important proof-theoretic result, but also underlies the development of type systems for programming languages. This fact suggests a potential importance of the result for a philosophy of code.

This paper is about how to aggregate outside opinion. If two experts are on one side of an issue, while three experts are on the other side, what should a non-expert believe? Certainly, the non-expert should take into account more than just the numbers. But which other factors are relevant, and why? According to the view developed here, one important factor is whether the experts should have been expected, in advance, to reach the same conclusion. When the agreement of two (...) (or of twenty) thinkers can be predicted with certainty in advance, their shared belief is worth only as much as one of their beliefs would be worth alone. This expectational model of belief dependence can be applied whether we think in terms of credences or in terms of all-or-nothing beliefs. (shrink)

Conciliationism faces a challenge that has not been satisfactorily addressed. There are clear cases of epistemically significant merely possible disagreement, but there are also clear cases where merely possible disagreement is epistemically irrelevant. Conciliationists have not yet accounted for this asymmetry. In this paper, we propose that the asymmetry can be explained by positing a selection constraint on all cases of peer disagreement—whether actual or merely possible. If a peer’s opinion was not selected in accordance with the proposed constraint, then (...) it lacks epistemic significance. This allows us to distinguish the epistemically significant cases of merely possible disagreement from the insignificant ones. (shrink)

This essay examines the anti-producing human body in its limit case of public self-induced starvation, as figured in Franz Kafka's short story ‘A Hunger Artist’ and Steve McQueen's film Hunger. Both works represent the fasting body as hollowed out, a resistance to capitalist-spectator capture that spatialises itself as a smoothing, a relative reconfiguration of parts to whole through the evacuation of flows. In both works the human body becomes a local body without organs, paradoxically disarticulated from the more complex assemblages (...) that constitute it while recording potential circuits of disturbance or resonance predicated upon the porousness of bodily boundaries. (shrink)

In the 1920s, Ackermann and von Neumann, in pursuit of Hilbert's programme, were working on consistency proofs for arithmetical systems. One proposed method of giving such proofs is Hilbert's epsilon-substitution method. There was, however, a second approach which was not reflected in the publications of the Hilbert school in the 1920s, and which is a direct precursor of Hilbert's first epsilon theorem and a certain "general consistency result" due to Bernays. An analysis of the form of this so-called "failed proof" (...) sheds further light on an interpretation of Hilbert's programme as an instrumentalist enterprise with the aim of showing that whenever a "real" proposition can be proved by ?ideal? means, it can also be proved by "real", finitary means. (shrink)

In this book, Zach Kelehear offers readers a new perspective on an important, dynamic, and sometimes daunting issue: managing successful school-based leadership. The author uses an arts-based approach to weave together notions of research-based leadership skills for successful school-based management with standards of professional competence as represented by the Interstate School Leaders Licensure Consortium Standards for School Leaders.

In addition to opening a fertile field for inquiry in analytical social epistemology, Miranda Fricker’s work has provided powerful conceptual tools that merge descriptive capacity and political potency. For this reason, over the last fifteen years, the conceptual repertoire introduced by the author has been well received in both academic and political arenas. At times, the concepts of both testimonial and hermeneutical injustice acquire excessive dimensions in the literature, and this undermines, on the one hand, their analytical precision and, on (...) the other, their usefulness. In this paper I argue against Fricker’s structural parallelism thesis and defend an independent treatment of each of these concepts. On this basis, to counteract the hyperinflation of the concept of hermeneutic injustice, I proceed with an exercise of conceptual precision. To this end, I identify the conditions that make hermeneutic injustice both unjust and hermeneutic. Finally, I present theoretical and practical reasons to encourage the rigorous use of these concepts. (shrink)

I exploit parallel considerations in the philosophy of mind and metaethics to argue that the reasoning employed in an important argument for panpsychism overgeneralizes to support an analogous position in metaethics: panmoralism. Next, I raise a number of problems for panmoralism and thereby build a case for taking the metaethical parallel to be a reductio ad absurdum of the argument for panpsychism. Finally, I contrast panmoralism with a position recently defended by Einar Duenger Bohn and argue that the two suffer (...) from similar problems. I conclude by drawing some general lessons for panpsychism. (shrink)

This thesis divides naturally into two parts, each concerned with the extent to which the theory of $L$ can be changed by forcing.The first part focuses primarily on applying generic-absoluteness principles to how that definable sets of reals enjoy regularity properties. The work in Part I is joint with Itay Neeman and is adapted from our paper Happy and mad families in $L$, JSL, 2018. The project was motivated by questions about mad families, maximal families of infinite subsets of $\omega (...) $ of which any two have only finitely many members in common. We begin, in the spirit of Mathias, by establishing a strong Ramsey property for sets of reals in the Solovay model, giving a new proof of Törnquist’s theorem that there are no infinite mad families in the Solovay model.In Chapter 3 we stray from the main line of inquiry to briefly study a game-theoretic characterization of filters with the Baire Property.Neeman and Zapletal showed, assuming roughly the existence of a proper class of Woodin cardinals, that the boldface theory of $L$ cannot be changed by proper forcing. They call their result the Embedding Theorem, because they conclude that in fact there is an elementary embedding from the $L$ of the ground model to that of the proper forcing extension. With a view toward analyzing mad families under $\mathsf {AD}^+$ and in $L$ under large-cardinal hypotheses, in Chapter 4 we establish triangular versions of the Embedding Theorem. These are enough for us to use Mathias’s methods to show that there are no infinite mad families in $L$ under large cardinals and that $\mathsf {AD}^+$ implies that there are no infinite mad families. These are again corollaries of theorems about strong Ramsey properties under large-cardinal assumptions and $\mathsf {AD}^+$, respectively. Our first theorem improves the large-cardinal assumption under which Todorcevic established the nonexistence of infinite mad families in $L$. Part I concludes with Chapter 5, a short list of open questions.In the second part of the thesis, we undertake a finer analysis of the Embedding Theorem and its consistency strength. Schindler found that the the Embedding Theorem is consistent relative to much weaker assumptions than the existence of Woodin cardinals. He defined remarkable cardinals, which can exist even in L, and showed that the Embedding Theorem is equiconsistent with the existence of a remarkable cardinal. His theorem resembles a theorem of Harrington–Shelah and Kunen from the 1980s: the absoluteness of the theory of $L$ to ccc forcing extensions is equiconsistent with a weakly compact cardinal. Joint with Itay Neeman, we improve Schindler’s theorem by showing that absoluteness for $\sigma $ -closed $\ast $ ccc posets—instead of the larger class of proper posets—implies the remarkability of $\aleph _1^V$ in L. This requires a fundamental change in the proof, since Schindler’s lower-bound argument uses Jensen’s reshaping forcing, which, though proper, need not be $\sigma $ -closed $\ast $ ccc in that context. Our proof bears more resemblance to that of Harrington–Shelah than to Schindler’s.The proof of Theorem 6.2 splits naturally into two arguments. In Chapter 7 we extend the Harrington–Shelah method of coding reals into a specializing function to allow for trees with uncountable levels that may not belong to L. This culminates in Theorem 7.4, which asserts that if there are $X\subseteq \omega _1$ and a tree $T\subseteq \omega _1$ of height $\omega _1$ such that X is codable along T, then $L$ -absoluteness for ccc posets must fail.We complete the argument in Chapter 8, where we show that if in any $\sigma $ -closed extension of V there is no $X\subseteq \omega _1$ codable along a tree T, then $\aleph _1^V$ must be remarkable in L.In Chapter 9 we review Schindler’s proof of generic absoluteness from a remarkable cardinal to show that the argument gives a level-by-level upper bound: a strongly $\lambda ^+$ -remarkable cardinal is enough to get $L$ -absoluteness for $\lambda $ -linked proper posets.Chapter 10 is devoted to partially reversing the level-by-level upper bound of Chapter 9. Adapting the methods of Neeman, Hierarchies of forcing axioms II, we are able to show that $L$ -absoluteness for $\left |\mathbf {R}\right |\cdot \left |\lambda \right |$ -linked posets implies that the interval $[\aleph _1^V,\lambda ]$ is $\Sigma ^2_1$ -remarkable in L.prepared by Zach Norwood.E-mail: [email protected]. (shrink)

Should we believe our controversial philosophical views? Recently, several authors have argued from broadly conciliationist premises that we should not. If they are right, we philosophers face a dilemma: If we believe our views, we are irrational. If we do not, we are not sincere in holding them. This paper offers a way out, proposing an attitude we can rationally take toward our views that can support sincerity of the appropriate sort. We should arrive at our views via a certain (...) sort of ‘insulated’ reasoning – that is, reasoning that involves setting aside certain higher-order worries, such as those provided by disagreement – when we investigate philosophical questions. (shrink)

La utilización de la denominación “Escuela de Salamanca” en referencia a los aspectos económicos es confusa y problemática, porque no hay argumentos convincentes para sostener que fuera una auténtica escuela de pensamiento económico (tal como la definen Schumpeter y Stigler). Sin embargo, desde Larraz y Grice-Hutchinson, los historiadores del pensamiento económico han utilizado habitualmente dicha denominación por su poder como “marca comercial” para la divulgación, y también para hacer referencia de forma breve y sencilla a las notables aportaciones analíticas de (...) un conjunto de doctores escolásticos españoles. De hecho, las monografías de los historiadores se han concentrado sobre todo en analizar las contribuciones de estos escolásticos (teoría monetaria, derechos de propiedad, etc.), más que en discutir los criterios que podrían definirles como una escuela en asuntos económicos. (shrink)

There are numerous studies that, from different perspectives, have dealt with the debate held in the Spanish Empire during the 16th century on the slavery of the American Indians, starring –among others– by Francisco de Vitoria and his disciples from the School of Salamanca, and also –outside the academic sphere– by Fray Bartolomé de las Casas and Juan Ginés de Sepúlveda. The purpose of this work is to study whether this debate made its mark in Spanish society. For this, it (...) is analyzed three theatrical pieces from the Golden Age signed by playwrights of the stature of Tirso de Molina, Lope de Vega and Pedro Calderón de Barca, who –given their enormous popularity– had the capacity to reach the wide audience that congregated in the corrals of comedies. Were these three writers influenced by the controversy over the Indians carried out, among other authors, by Vitoria, Las Casas and Sepúlveda? Did they fully grasp in their works the subtle debate that Vitoria, Las Casas and Sepúlveda maintained when they interpreted Aristotelian arguments on slavery and the consequences that derived from them in terms of the possibility of enslaving or not the Indians? (shrink)

La revolución digital de trasfondo transhumanista en la que estamos inmersos plantea un escenario de robotización también de la función jurisdiccional. El uso intensivo de Big Data e Inteligencia Artificial (IA) abriría la posibilidad de que sean las máquinas quienes razonen jurídicamente y sean -en definitiva- quienes tomen las decisiones dirimentes de los conflictos sociales so capa de una mayor rapidez, objetividad y predictibilidad; en definitiva, dada su evidente eficiencia en comparación con los juzgadores humanos. Sin embargo, conviene examinar atentamente (...) las limitaciones de la IA aplicada a la argumentación jurídica. Merece la pena recapacitar acerca de la idoneidad social de una eventualidad tal. Se concluye escuchando voces autorizadas que se han pronunciado al respecto, cuestionando la existencia de una ‘justicia transhumanista’, pues el uso intensivo y extensivo de la IA no dejaría de ser una capitulación de la ciencia jurídica. Ahora bien, un uso encuadrado dentro de sus posibilidades abre una oportunidad para el mejor razonamiento jurídico y la extensión de los métodos de resolución de conflictos alternativos a la jurisdicción estatal. (shrink)

On some accounts of vagueness, predicates like “is a heap” are tolerant. That is, their correct application tolerates sufficiently small changes in the objects to which they are applied. Of course, such views face the sorites paradox, and various solutions have been proposed. One proposed solution involves banning repeated appeals to tolerance, while affirming tolerance in any individual case. In effect, this solution rejects the reasoning of the sorites argument. This paper discusses a thorny problem afflicting this approach to vagueness. (...) In particular, it is shown that, on the foregoing view, whether an object is a heap will sometimes depend on factors extrinsic to that object, such as whether its components came from other heaps. More generally, the paper raises the issue of how to count heaps in a tolerance-friendly framework. (shrink)

Although arguments for and against competing theories of vagueness often appeal to claims about the use of vague predicates by ordinary speakers, such claims are rarely tested. An exception is Bonini et al. (1999), who report empirical results on the use of vague predicates by Italian speakers, and take the results to count in favor of epistemicism. Yet several methodological difficulties mar their experiments; we outline these problems and devise revised experiments that do not show the same results. We then (...) describe three additional empirical studies that investigate further claims in the literature on vagueness: the hypothesis that speakers confuse ‘P’ with ‘definitely P’, the relative persuasiveness of different formulations of the inductive premise of the Sorites, and the interaction of vague predicates with three different forms of negation. (shrink)

Can machines think? Until what happened today, I thought that no human-made machine could ever think as a human does. I now know that I was wrong.

Wie nahe stehen sich die jüdische Gedankenwelt und die Ideen Sören Kierkegaards? In einer dialogischen Konstellation findet die geistige Wahlverwandtschaft darauf eine Antwort. Richard Blättel nimmt dazu drei alttestamentarische Erzählungen mit existenzieller Färbung in den Blick: den Sündenfall, die Opferung Isaaks und Hiob. Sowohl Kierkegaard als auch die jüdischen Denker haben sich mit den biblischen Narrativen befasst, wobei das Motiv der Wiederholung zum Brennpunkt wird. Zwischen Schöpfung und Offenbarung kreist das erzählende Denken, das sich von der traditionellen Denkgeschichte des Abendlandes (...) abgrenzt. Dabei entsteht philosophisches Pathos als eine Form leidenschaftlichen Denkens. (shrink)

Wie nahe stehen sich die jüdische Gedankenwelt und die Ideen Sören Kierkegaards? In einer dialogischen Konstellation findet die geistige Wahlverwandtschaft darauf eine Antwort. Richard Blättel nimmt dazu drei alttestamentarische Erzählungen mit existenzieller Färbung in den Blick: den Sündenfall, die Opferung Isaaks und Hiob. Sowohl Kierkegaard als auch die jüdischen Denker haben sich mit den biblischen Narrativen befasst, wobei das Motiv der Wiederholung zum Brennpunkt wird. Zwischen Schöpfung und Offenbarung kreist das erzählende Denken, das sich von der traditionellen Denkgeschichte des Abendlandes (...) abgrenzt. Dabei entsteht philosophisches Pathos als eine Form leidenschaftlichen Denkens. (shrink)

Hilbert's ε-calculus is based on an extension of the language of predicate logic by a term-forming operator εx. Two fundamental results about the ε-calculus, the first and second epsilon theorem, play a rôle similar to that which the cut-elimination theorem plays in sequent calculus. In particular, Herbrand's Theorem is a consequence of the epsilon theorems. The paper investigates the epsilon theorems and the complexity of the elimination procedure underlying their proof, as well as the length of Herbrand disjunctions of existential (...) theorems obtained by this elimination procedure. (shrink)