In this paper I deal with the relation between the disjunction thesis—that the truthmaking relation is distributed over a disjunction—and the necessary connection thesis—that the existence of some entities requires the existence of other distinct entities. I will first show that because of this very relation, the arguments for and against the disjunction thesis that overlook its metaphysical considerations will fail. Finally, I will show that the commitment produced by truthmaker maximalism to totality states (...) of affairs, or some relevantly similar things, requires one to accept a necessary connection that disaffirms the disjunction thesis. (shrink)

The correspondence theory of truth has experienced something of a revival recently in the form of the Truthmaker Axiom: whatever is true, something makes it true. We consider various postulates which have been proposed to characterize truthmaking, in particular, the Disjunction Thesis (DT), that whatever makes a disjunction true must make one or other disjunct true. In conjunction with certain other assumptions, DT leads to triviality. We show that there are elaborations of truthmaking on which DT holds (...) (which must therefore take steps to avoid the triviality); but that there are more plausible accounts of truthmaking on which DT fails. (shrink)

In the paper we discuss criticisms against David Armstrong’s general theory of truthmaking by Gonzalo Rodriguez-Pereyra, Peter Schulte and Benjamin Schnieder, and conclude that Armstrong’s theory survives these criticisms. Special attention is given to the problems concerning Entailment Principle, Conjunction Thesis, Disjunction Thesis and to the notion of explanation.

This paper is a response to replies by Dan López de Sa and Mark Jago to my ‘Truthmaking, Entailment, and the Conjuction Thesis’. In that paper, my main aim was to argue against the Entailment Principle by arguing against the Conjunction Thesis, which is entailed by the Entailment Principle. In the course of so doing, although not essential for my project in that paper, I defended the Disjunction Thesis. López de Sa has objected both to my (...) defence of the Disjunction Thesis and my case against the Conjunction Thesis. I shall show that his objections are unfounded and based on serious misunderstandings of my position, what the relevant debate is, and some fundamental notions of Truthmaker Theory. Jago argues that accepting the Disjunction Thesis and rejecting the Conjunction Thesis is hard to maintain. But I show that Jago has not shown that accepting the Disjunction Thesis while rejecting the Conjunction Thesis is impossible or even hard to maintain. Jago believes that, to accept the Disjunction Thesis while rejecting the Conjunction Thesis, one needs to reject his axiom (T3), which says that all the truthmakers for <P&P> are truthmakers for <P>. I argue that there are reasons to reject such a principle, and the version of it that says that what makes <P&P> true makes <P> true. (shrink)

Gonzalo Rodriguez-Pereyra (2006) argues against attempts to preserve the entailment principle (or a restriction of it) while avoiding the explosion of truthmakers for necessities and truthmaker triviality. In doing so, he both defends the disjunction thesis--if something makes true a disjunctive truth, then it makes true one of its disjuncts--, and rejects the conjunction thesis--if something makes tue a conjunctive truth, then it makes true each of its conjuncts. In my discussion, I provide plausible counterexamples to the (...) disjunction thesis, and contend that Rodriguez-Pereyra's general defence of it fails. Then I defend the conjunction thesis from Rodriguez-Pereyra's case against it. (shrink)

Rodriguez-Pereyra (2006) argues for the disjunction thesis but against the conjunction thesis. I argue that accepting the disjunction thesis undermines his argument against the conjunction thesis.

This article examines the idea of disjunctive rights—an idea first suggested by Joel Feinberg and more recently advocated by Richard Arneson. Using a hypothetical scenario to bring forward a conflict between two rights that cannot be simultaneously fulfilled, the suggestion that the conflict can be solved by describing the right-holders as holding disjunctive rights—rights that involve, in a significant way, a disjunction—is scrutinized. Several interpretations of the idea of disjunctive rights are examined from the perspectives of the interest theory (...) and will theory of rights. Ultimately, the idea of disjunctive rights fails to provide an acceptable solution to the problem at hand, as each interpretation has unacceptable implications. This conclusion challenges the compossibilist thesis, according to which moral rights do not, ultimately, conflict. Alternatively, if one wishes to keep the possibility of compossibility and disjunctive rights, the mainstream theories of rights must be revised or rejected. (shrink)

The logician Kurt Godel in 1951 established a disjunctive thesis about the scope and limits of mathematical knowledge: either the mathematical mind is equivalent to a Turing machine (i.e., a computer), or there are absolutely undecidable mathematical problems. In the second half of the twentieth century, attempts have been made to arrive at a stronger conclusion. In particular, arguments have been produced by the philosopher J.R. Lucas and by the physicist and mathematician Roger Penrose that intend to show that (...) the mathematical mind is more powerful than any computer. These arguments, and counterarguments to them, have not convinced the logical and philosophical community. The reason for this is an insufficiency if rigour in the debate. The contributions in this volume move the debate forward by formulating rigorous frameworks and formally spelling out and evaluating arguments that bear on Godel's disjunction in these frameworks. The contributions in this volume have been written by world leading experts in the field. (shrink)

The natural interpretation of counterfactuals with disjunctive antecedents involves selecting from each of the disjuncts the worlds that come closest to the world of evaluation. It has been long noticed that capturing this interpretation poses a problem for a minimal change semantics for counterfactuals, because selecting the closest worlds from each disjunct requires accessing the denotation of the disjuncts from the denotation of the disjunctive antecedent, which the standard boolean analysis of or does not allow (Creary and Hill, Philosophy of (...) Science 43:341–344, 1975; Nute, Journal of Philosophy 72:773–778, 1975; Fine, Mind 84(335):451–458, 1975; Ellis et al. Journal of Philosophical Logic 6:335–357, 1977). This paper argues that the failure to capture the natural interpretation of disjunctive counterfactuals provides no reason to abandon a minimal change semantics. It shows that the natural interpretation of disjunctive counterfactuals is expected once we refine our assumptions about the semantics of or and the logical form of conditionals, and (i) we assume that disjunctions introduce propositional alternatives in the semantic derivation, in line with independently motivated proposals about the semantics of or (Aloni, 2003a; Simons, Natural Language Semantics 13:271–316, 2005; Alonso-Ovalle, Disjunction in Alternative Semantics. PhD thesis, 2006); and (ii) we treat conditionals as correlative constructions, as advocated in von Fintel (1994), Izvorski (Proceedings of NELS 26, 1996), Bhatt and Pancheva (2006), and Schlenker (2004). (shrink)

In this dissertation, I argue that all extant theories of prudential value are either a) enumeratively deficient, in that they are unable to accommodate everything that, intuitively, is a basic constituent of prudential value, b) explanatorily deficient, in that they are at least sometimes unable to offer a plausible story about what makes a given thing prudentially valuable, or c) both. In response to the unsatisfactory state of the literature, I present my own account, the Disjunctive Hybrid Theory or DHT. (...) DHT answers to and remedies each of the above inadequacies in a way that no other approach can. This account has the following general structure:Disjunctive Hybrid Theory (DHT): Thing x is basically good for person P if and only if x is either a) cared about (sufficiently and in the right way) by P, b) a bearer of (the right kind of) attitude-independent value, or c) both.Although it follows other recent accounts in combining elements from objective and subjective theories, DHT is a hybrid theory of a quite new kind. This is because it denies both subjective necessity (the constraint that, if thing x is to be basically good for person P, P must have some pro-attitude toward x) and objective necessity (the constraint that, if thing x is to be basically good for person P, x must have some attitude-independent value). I argue that the rejection of both necessity claims is called for if we are to move beyond the enumerative and explanatory limitations of existing accounts.I begin by outlining the general structure of DHT. I then argue, against various recent authors, that desire-satisfactionism remains the most appealing subjectivist approach to prudential value, in that it is best able to capture the central subjectivist insight. This insight is that a person can confer prudential value upon things by caring about them (sufficiently and in the right way). The subjectivist strand of DHT will thus be a version of desire-satisfactionism, which must be interpreted in line with what I call the object, as opposed to the combo, view. I move on to further motivate and develop the second, objectivist strand of DHT. This part of the theory involves a commitment to robustly attitude-independent prudential goods. I close by addressing some puzzles for the theory, and considering some of its more specific applications. (shrink)

This thesis motivates a novel account of desire as the best explanation of an intuitive datum. The intuitive datum is that often when an agent desires P she will immediately, outright know that she has a reason to bring P about. Existing explanations of the intuitive datum cannot simultaneously satisfy two desiderata. We want to explain how desires enable outright knowledge of reasons and also explain the fallibility of desires. Existing views satisfy the first desideratum at the expense of (...) the second, or vice versa. I propose an epistemological disjunctivist account of desire that satisfies both. On this view, a desire for P represents the value of P in a manner analogous to perception. Desires come in two distinct epistemic kinds: an awareness of value or an illusion of value. An awareness of value enables outright knowledge of reasons and allows the agent to tell by reflection that she has such knowledge. An illusion of value merely seems to provide grounds for knowledge, which explains the fallibility of desires. The proposed account is a strong candidate for the truth because it best explains central features of our practical agency. (shrink)

We show that the name “Lucas-Penrose thesis” encompasses several different theses. All these theses refer to extremely vague concepts, and so are either practically meaningless, or obviously false. The arguments for the various theses, in turn, are based on confusions with regard to the meaning of these vague notions, and on unjustified hidden assumptions concerning them. All these observations are true also for all interesting versions of the much weaker thesis known as “Gö- del disjunction”. Our main (...) conclusions are that pure mathematical theorems cannot decide alone any question which is not purely mathematical, and that an argument that cannot be fully formalized cannot be taken as a mathematical proof. (shrink)

Daniel Bell’s multidimensional view of modern social life as a disjunction of differing realms provides an effective example of a sociological analysis that defies typical notions of Left/Right and radical/conservative. Within this framework, Bell moves between traditional alliances, and his unwillingness to take sides makes it difficult to place him within traditional categories. Using Bell as an example, this paper will question the relevance of Right and Left in sociological discourse, and suggest that the distinction between conservative and radical (...) is more substantive. (shrink)

Grice observes that the primary discourse function of disjunction is the presentation of alternatives, each of which is relevant in the same way to a given topic. After a brief introduction , I offer in Chapter Two an account of Grice's observation and of further felicity conditions on disjunction, for example, the constraint against disjunctions in which one disjunct entails another. Using an enriched version of the Stalnakerian model of assertion, I define two constraints on information update--Relevant Informativity (...) and Simplicity--and show that these suffice to account for the observations. ;I then argue that the requirement to abide by Relevant Informativity and Simplicity provides a basis for an account of two further properties of disjunctive sentences: their presupposition projection properties and the possibility of anaphora between disjuncts. I argue that presuppositions project in disjunction except where projection would lead to infelicity of the kind characterized in Chapter Two. To state this account, a treatment of presupposition which allows projection to be sensitive to considerations of felicity is required. I show that the Stalnakerian view of presupposition, combined with Heim's notion of local accommodation, provides the necessary framework. ;Similarly, I argue that anaphora across disjunction is disallowed only when it leads to an infelicitous disjunction. In certain configurations, anaphora between disjuncts leads to entailment between disjuncts, which is ruled out independently. The account is given using a version of Neale's E-type analysis of unbound anaphora. I show that the analysis has further desirable consequences with respect to more complex examples of inter-disjunct anaphora. ;Throughout Chapters Three and Four, I contrast my own proposals with accounts given in the Dynamic Semantic literature, offering a critique of Dynamic Semantic approaches to the phenomena discussed. ;In Chapter Five, I examine anaphora between NPs contained inside a disjunction and a pronoun in a following sentence. I argue that these pronouns are also E-type, but show that these cases require a reformulation of the E-type analysis. I develop a new account in which the interpretation of E-type pronouns is derived compositionally from the content of the antecedent clause. (shrink)

The theory of evolution makes sense of the emergence of consciousness. Reduction is not wrong as such, but must not be totalised. The fact that we are star stuff does not preclude the novelty of consciousness. Materialism is naturalism, but naturalism need not be materialism. Neural pathways are relevant but are not the total picture. The central thesis is about David Chalmers’s philosophy being based on an exclusive disjunction. An inclusive disjunction is, when explained, more appropriate. Functionalism (...) is appropriate. Thomas Nagel’s philosophy on first person ontology can still be maintained. Quantum and complexity theories’ hypothesis on consciousness is more compatible with freedom of decision than classical theories. (shrink)

This paper shows that grounded dispositions are necessarily coextensive with disjunctive properties. It responds to several objections against this thesis, and then shows how to construct a disjunctive property necessarily coextensive with an arbitrary grounded disposition.

This paper shows that grounded dispositions are necessarily coextensive with disjunctive properties. It responds to several objections against this thesis, and then shows how to construct a disjunctive property necessarily coextensive with an arbitrary grounded disposition.

Abstract:We argue that traditional formulations of the reduction thesis that tie it to privileged relational operations do not suffice for Peirce’s justification of the categories and invite the charge of gerrymandering to make it come out as true. We then develop a more robust invariant formulation of the thesis, one that is immune to that charge, by explicating the use of triads in any relational operations. The explication also allows us to track how Thirdness enters the structure of (...) higher order relations and even to propose a numerical measure of it. Our analysis reveals new conceptual phenomena when negation or disjunction are used to compound relations. (shrink)

I propose an account truthmaking that provides truthmakers for negative truths. The account replaces Truthmaker Necessitarianism with a "Duplication Principle", according to which a suitable entity T is a truthmaker for a proposition P just in case the existence of an appropriate counterpart of T entails the truth of P, where the counterpart relation is cashed out in terms of qualitative duplication. My account captures an intuitive notion of truthmakers as "things the way they are", validates two appealing principles about (...) entailment and containment proposed by David Armstrong, and invalidates the controversial Disjunction Thesis. (shrink)

Is it possible that there are extended simples—material objects extended in space or spacetime that have no proper parts? The most commonly cited argument for this possibility is based on a version of the Humean principle: namely (and with some qualifications), any pattern of instantiation of a fundamental relation is possible. In this paper, we make the Humean argument fully explicit, and criticise it from three aspects—the Disjunction problem, the Pluralist problem, and the Accidentality problem. First, the original argument (...) only shows a disjunctive thesis: either extended simples are possible, or unextended complexes are possible. In order to reach the desired conclusion, some additional premise is needed. Yet, even though we agree that the Disjunction problem can be met, we argue that the Humean argument fails to establish the possibility of extended simples, for two reasons: the first comes from compositional pluralism, and the second is about the definition of accidental properties. We contend that the latter two problems put the proponents of the Humean argument in serious difficulty. Thus, metaphysicians who hold that there are extended simples should find better arguments for this view. (shrink)

According to one tradition in realist philosophy, 'truthmaking' amounts to necessitation. That is, an object x is a truthmaker for the claim A if x exists, and the existence of x necessitates the truth of A. I argued in my paper "Truthmakers, Entailment and Necessity" [14], that if we wish to use this account of truthmaking, we ought understand the entailment connective "=>" in such a claim as a relevant entailment, in the tradition of Anderson and Belnap and their co-workers (...) [1, 2, 8, 11]. Furthermore, I proposed a number of theses about truthmaking as necessitation. The most controversial of these is the disjunction thesis: x makes a disjunction A v B true if and only if it makes one of the disjuncts (A or B) true. That paper left one important task unfinished. I did not explain how the theses about truthmaking could be true together. In this paper I give a consistency proof, by providing a model for the theses of truthmaking in my earlier paper. This result does two things. First, it shows that the theses of truthmaking are jointly consistent. Second, it provides an independently philosophically motivated formal model for relevant logics in the 'possible worlds' tradition of Routley and Meyer [8, 16, 17]. (shrink)

By considering the epistemology and relations among certain philosophical problems, I argue for a disjunctive thesis: either (1) it is highly probable that there are (i) several (ii) mutually independent philosophical reductios of highly commonsensical propositions that are successful—so several aspects of philosophy have succeeded at refuting common sense—or (2) there is enough hidden semantic structure in even simple sentences of natural language to make philosophers highly unreliable at spotting deductive validity in some of the simplest cases—so we are (...) much worse at logic than we think and cannot, in general, know when our own arguments are valid. The untoward consequences of each disjunct are explained. (shrink)

Autonomy, as I understand it, is associated with a family of freedom concepts: free will, free choice, free action, and the like. In much of the philosophical literature discussed in this chapter, issues are framed in terms of freedom rather than autonomy, but we are talking about (aspects of) the same thing. Libertarians argue that determinism precludes autonomy by, for example, precluding an agent's being ultimately responsible for anything. Some compatibilist believers in autonomy argue that libertarians rely on indeterminism in (...) a way that deprives us of autonomy-level control over our decisions. Theorists who contend that no human being is autonomous can benefit from arguments on both sides, alleging that libertarians decisively reveal the ordinary person's notion of autonomy, an incompatibilist notion, and that compatibilist critics of libertarianism show that the notion is incoherent or unsatis-fiable. Is there a way to use the resources both of libertarianism and of compatibilism in defending the following thesis: The claim that there are autonomous human beings is more credible than the claim that there are none? -/- I believe that the answer is “yes.” I defended that answer in Autonomous Agents. Part of my strategy was to develop an account of an ideally self-controlled agent (where self-control is understood as the contrary of akrasia [roughly, weakness of will]), to argue that even such an agent may fall short of autonomy, and to ask what may be added to ideal self-control to yield autonomy. I offered two answers, one for compatibilists and another for libertarians. I then argued that a certain disjunctive thesis involving both answers (identified in Section 4 below) is more credible than the thesis that there are no autonomous human beings. (shrink)

We present a puzzle about knowledge, probability and conditionals. We show that in certain cases some basic and plausible principles governing our reasoning come into conflict. In particular, we show that there is a simple argument that a person may be in a position to know a conditional the consequent of which has a low probability conditional on its antecedent, contra Adams’ Thesis. We suggest that the puzzle motivates a very strong restriction on the inference of a conditional from (...) a disjunction. (shrink)

In his Gibbs lecture, Gödel argued for the thesis that either the human mind is not a Turing machine, or there exist absolutely undecidable mathematical propositions. He believed that this disjunction can be deduced with mathematical certainty from certain results in mathematical logic. He thought that his disjunctive thesis is of great philosophical importance. First, Gödel's argument for his disjunctive thesis is discussed. It is argued that thisargument contains an ambiguity. But when it is made precise (...) in a certain way, the argument is seen to be ultimately inescapable. Second, the disjuncts of the thesis are considered in their own right. It is argued that there are today no convincing arguments in favor of the first disjunct, nor are there at present convincing arguments against it. But there do exist today strong reasons to believe the second disjunct to be true, although these reasons do not establish the disjunct with anything like mathematical certainty. (shrink)

The aim of this paper is to present and analyze the truthmaker monism , a result according to which any truthmaker makes true any true proposition. Truthmaker monism depends on the characterization of the truthmaking relation in terms of strict implication, the principle of excluded middle and the so called disjunction thesis. I will restrict the discussion to a theory of truthmakers of empirical truths and I will argue that, in the scope of such a theory, the problem (...) does not lie in the use of strict implication neither in the excluded middle but, rather, in the disjunction thesis, that must be rejected. (shrink)

The exclusive component of unembedded disjunctions is standardly derived as a conversational implicature by assuming that or forms a lexical scale with and. It is well known, however, that this assumption does not suffice to determine the required scalar competitors of disjunctions with more than two atomic disjuncts (McCawley, Everything that linguists have always wanted to know about logic* (But were ashamed to ask). Chicago University Press, Chicago, 1993, p. 324; Simons, “Or”: Issues in the semantics and pragmatics of (...) class='Hi'>disjunction. Ph.D. thesis, Cornell University, Ithaca, NY, 1998). To solve this, Sauerland (Linguist Philos 27(3): 367–391, 2004) assumes that or forms a lexical scale with two otherwise unattested silent connectives ( ${\mathbb{L}}$ and ${\mathbb{R}}$ ) that retrieve the left and right terms of a disjunction. A number of recent works have proposed an Alternative Semantics for indefinites and disjunction to account for their interaction with modals and other propositional operators (Kratzer and Shimoyama, In: Otsu Y (ed) The Proceedings of the Third Tokyo Conference on Psycholinguistics. Hituzi Syobo, Tokyo, pp. 1–25, 2002; Aloni, In: Weisgerber M (ed) Proceedings of the Conference “SuB7—Sinn und Bedeutung”. Arbeitspapier Nr. 114. Konstanz, pp. 28–37, 2003; Simons, Nat Lang Semantics 13: 271–316, 2005; Alonso-Ovalle, Disjunction in alternative semantics. Ph.D. thesis, University of Massachusetts, Amherst, MA, 2006). We note that the McCawley–Simons problem does not arise in an Alternative Semantics, if we assume that the set of pragmatic competitors to a disjunction is the closure under intersection of the set of propositions that it denotes. An adaptation of the strengthening mechanism presented in Fox (In: Sauerland U, Stateva P (eds) Presupposition and implicature in compositional semantics. MacMillan, Palgrave, pp. 71–120, 2007) allows for the derivation of the exclusive component of disjunctions with more than two atomic disjuncts without having to rely on the ${\mathbb{L}}$ and ${\mathbb{R}}$ operators. The proposal extends to the case of disjunctions with logically dependent disjuncts. (shrink)

In his 1951 Gibbs Memorial Lecture, Kurt Gödel put forth his famous disjunction that either the power of the mind outstrips that of any machine or there are absolutely unsolvable problems. The view that there are no absolutely unsolvable problems is optimism, the view that there are such problems is pessimism. In his 1995—and, revised in 2013—Verificationism Then and Now, Per Martin-Löf presents an illustrative argument for a constructivist form of optimism. In response to that argument, Solomon Feferman points (...) out that Martin-Löf’s reasoning relies upon constructive understandings of key philosophical notions. In the vein of Feferman’s analysis, one might be object to Martin-Löf’s argument for either its reliance upon constructivist considerations, or for its appeal to non-unproblematically mathematical premises. We argue that both of these responses fall short. On one hand, to be critical of Martin-Löf’s reasoning for its constructiveness is to reject what would otherwise be a scientific advance on the basis of the assumption of constructivism’s falsehood or implausibility, which is of course uncharitable at best. On the other hand, to object to the argument for its use of non-unproblematically mathematical premises is to assume that there is some philosophically neutral mathematics, which is implausible. Martin-Löf’s argument relies upon his third law, the claim that from the impossibility of a proof of a proposition we can construct a proof of its negation. We close with a discussion of some ways in which this claim can be criticized from the constructive point of view. Specifically, we contend that Martin-Löf’s third law is incompatible with what has been called “Poincaré’s Principle of Epistemic Conservation”, the thesis that genuine increase in mathematical knowledge requires subject-specific insight. (shrink)

In this note two propositions about the epistemic formalization of Church's Thesis are proved. First it is shown that all arithmetical sentences deducible in Shapiro's system EA of Epistemic Arithmetic from ECT are derivable from Peano Arithmetic PA + uniform reflection for PA. Second it is shown that the system EA + ECT has the epistemic disjunction property and the epistemic numerical existence property for arithmetical formulas.

This thesis is a defense of the Content View on perceptual experience, of the idea that our perceptual experiences represent the world as being a certain way and so have representational content. Three main issues are addressed in this work. Firstly, I try to show that the Content View fits very well both with the logical behaviour of ordinary ascriptions of seeing-episodes and related experiential episodes, and with our pretheoretical intuitions about what perceiving and experiencing ultimately are: that preliminary (...) analysis speaks for the prima facie plausibility of such a view. Secondly, I put forward a detailed account of perceptual episodes in semantic terms, by articulating and arguing for a specific version of the Content View. I provide arguments for the following theses: Perceptual content is two-layered so it involves an iconic level and a discrete or proto-propositional level. Perceptual content is singular and object-dependent or de re, so it includes environmental objects as its semantic constituents. The phenomenal character of perceptual experience is co-determined by the represented properties together with the Mode, but not by the perceived objects: that is what I call an impure representationalism. Perceptual content is 'Russellian': it consists of worldly objects, properties and relations. Both perceptual content and phenomenal character are 'wide' or determined by environmental factors, thus there is no Fregean, narrow perceptual content. Thirdly, I show that such a version of the Content View can cope with the objections which are typically moved against the Content View as such by the advocates of disjunctivism. I myself put forward a moderately disjunctivist version of the Content View, according to which perceptual relations must be told apart from hallucinations as mental states of a different kind. Such a disjunctivism is 'moderate' insofar as it allows genuinely relational perceptual experiences and hallucinations to share a positive phenomenal character, contrary to what Radical Disjunctivism cum Naïve Realism holds. Showing that the Content View vindicates our pre-theoretical intuitions and does justice of our ordinary ascriptive practices, articulating a detailed and argued version of the Content View, and showing that such a version is not vulnerable to the standard objections recently moved to the Content View by the disjunctive part, all that can be considered as a big, multifaceted Argument for the Content View. (shrink)

MA Thesis. Biomedical ethics does not lend itself to easy categorisation as either a 'theoretical' or a 'practical' enterprise because inquiry into the quandaries of morality requires both situational and 'translocal' perspectives. These types of investigation bring into question the legitimacy of the theory/practice divide that has dominated intellectual thought since antiquity. This division hinders the development of bioethics by fostering internal dispute within the discipline regarding appropriate methodology and the practice of clinical ethics. In this thesis, I (...) argue that much of these disciplinary disjunctions are due to an undue labeling of bioethics as either 'applied ethics' or 'practical ethics', and a failure to recognise the intricate way in which theory and practice inform each other and are integral and interrelated parts of moral deliberation. I argue for an integration of the theory and practice of bioethics. (shrink)

This thesis challenges a general prejudice against visualization in the history of logic and mathematics, by providing a semantic analysis of two graphical representation systems--a traditional Venn diagram representation system and an extension of it. While Venn diagrams have been used to solve problems in set theory and to test the validity of syllogisms in logic, they have not been considered valid proofs but heuristic tools for finding valid formal proofs. ;I present Venn diagrams which have been used in (...) logic as a formal system of representation equipped with its own syntax and semantics. I also show that Venn-I, with the rules of transformation that I specify, is sound and complete. The soundness of Venn-I refutes a worry that mathematicians and logicians have about graphical representation: Fallacies often have arisen from the misuse of diagrams in mathematical proofs, especially in geometry. However, the validity of the transformation rules assures us that the correct application of these rules will not lead to fallacies. ;I extend Venn-I so that this new system has a general way to convey disjunctive information. A new formation rule is introduced and new transformation rules are added. I call this extended system Venn-II. The semantics of Venn-II is formalized as an extension of the semantics of Venn-I. The soundness and completeness of Venn-II are also proven. I then show that Venn-II and a monadic first-order language are equivalent in their expressiveness. ;The analysis of Venn-I and Venn-II leads to interesting issues which have their analogues in other deductive systems. I conclude the thesis with a discussion of some fundamental differences between graphical systems and linguistic systems. (shrink)

In “Lectio 55” of his Notule libri Priorum, Robert Kilwardby discussed various objections that had been raised against Aristotle’s Theses. The first thesis, AT1, says that no proposition q is implied both by a proposition p and by its negation, ∼p. AT2 says that no proposition p is implied by its own negation. In Prior Analytics, Aristotle had shown that AT2 entails AT1, and he argued that the assumption of a proposition p such that (∼p → p) would be (...) “absurd”. The unrestricted validity of AT1, AT2, however, is at odds with other principles which were widely accepted by medieval logicians, namely the law Ex Impossibili Quodlibet, EIQ, and the rules of disjunction introduction. Since, according to EIQ, the impossible proposition (p ∧ ∼p) implies every proposition, it also implies ∼(p∧∼p), in contradiction to AT2. Furthermore, by way of disjunction introduction, the proposition (p∨∼p) is implied both by p and by ∼p, in contradiction to AT1. Kilwardby tried to defend AT1, AT2 against these objections by claiming that EIQ holds only for accidental but not for natural implications. The second argument, however, cannot be refuted in this way because Kilwardby had to admit that every disjunction (p ∨ q) is naturally implied by its disjuncts. He therefore introduced the further requirement that, in order to constitute a genuine counterexample to AT1, (p → q) and (∼p → q) have to hold “by virtue of the same thing”. In a recently published paper, Spencer Johnston accepted this futile defence of AT1 and developed a formal semantics that would fit Kilwardby’s presumably connexive implication. This procedure, however, is misguided because the remaining considerations of Lesson 55  which were entirely ignored by Johnston  show that Kilwardby eventually recognized that AT2 is bound to fail. After all he concluded: “So it should be granted that from the impossible its opposite follows, and that the necessary follows from its opposite”. (shrink)

Fish proposes that we need to elucidate what 'disjunctivism' stands for, and he also proposes that it stands for the rejection of a principle about the nature of experience that he calls the decisiveness principle. The present paper argues that his first proposal is reasonable, but then argues, in Section II, that his positive suggestion does not draw the line between disjunctivism and non-disjunctivism in the right place. In Section III, it is argued that disjunctivism is a thesis about (...) the special nature of perceptual experience, and the thesis as elucidated here is then distinguished from and related to certain other ideas about perception, namely, direct realism and also McDowell's epistemological disjunctivism. (shrink)

This paper defends the thesis that counterfactuals are strict conditionals. Its purpose is to show that there is a coherent view according to which counterfactuals are strict conditionals whose antecedent is stated elliptically. Section 1 introduces the view. Section 2 outlines a response to the main argument against the thesis that counterfactuals are strict conditionals. Section 3 compares the view with a proposal due to Aqvist, which may be regarded as its direct predecessor. Sections 4 and 5 explain (...) how the view di ers from the theories of counterfactuals advocated by Stalnaker and Lewis, and from some contextualist strict conditional accounts of counterfactuals that have emerged recently. Finally, section 6 addresses the thorny issue of disjunctive antecedents. (shrink)

Kripke holds the thesis that identity statements containing natural kind terms are if true, necessarily true; these statements can be denominated theoretical identities. Kripke alleges that the necessity of theoretical identities grounds on the linguistic feature that natural kind terms are rigid designators. Nevertheless, I argue that the conception of natural kind terms as rigid designators, in one of their most natural views, hinders the establishment of the truth of theoretical identities and thus of their necessity. However, in Kripke’s (...) works another proposal, not linguistic but metaphysical, is found to justify the presumed necessity of theoretical identities; it grounds on essentialism concerning natural kinds. In this regard, I question some of Kripke’s main claims, focusing on one of the main examples of theoretical identities put forward by Kripke, i.e., “Water is H2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}O”. I challenge his a priori claims concerning what should be the essence of a natural kind like water. Furthermore, I adduce that the character of that theoretical identity is not that claimed by Kripke, since in the term flanking the right side of the identity sign it has to be resorted to the notion of similarity or it should have the form of a disjunction of a cluster of substances. (shrink)

I argue for the thesis (UL) that there are certain logical abilities that any rational creature must have. Opposition to UL comes from naturalized epistemologists who hold that it is a purely empirical question which logical abilities a rational creature has. I provide arguments that any creatures meeting certain conditions—plausible necessary conditions on rationality—must have certain specific logical concepts and be able to use them in certain specific ways. For example, I argue that any creature able to grasp theories (...) must have a concept of conjunction subject to the usual introduction and elimination rules. I also deal with disjunction, conditionality and negation. Finally, I put UL to work in showing how it could be used to define a notion of logical obviousness that would be well suited to certain contexts—e.g. radical translation and epistemic logic—in which a concept of obviousness is often invoked. (shrink)

In this thesis we construct a critical encounter between the composer John Cage and the philosopher Gilles Deleuze. This encounter circulates through a constellation of problems found across and between mid-twentieth century musical, artistic, and philosophical practices, the central focus for our line of enquiry being the concept of experimentation. We emphasize the production of a method of experimentation through a practice historically situated with regards to the traditions of the respective fields of music and philosophy. However, we argue (...) that these experimental practices are not reducible to their historical traditions, but rather, by adopting what we term a problematic reading, or transcendental critique, with regards to historical givens, they take their historical situation as the site of an experimental departure. We follow Cage through his relation to the history of Western classical music, his contemporaries in the musical avant-garde, and artistic movements surrounding and in some respects stemming from Cage’s work, and Deleuze through his relation to Kant, phenomenology, and structuralism, in order to map the production of a practice of experimentation spanning music, art, and philosophy. Some specific figures we engage with in these respective traditions include Jean-Phillipe Rameau, Pierre Schaeffer, Marcel Duchamp, Pierre Boulez, Robert Morris, Yoko Ono, La Monte Young, Edmund Husserl, Maurice-Merleau-Ponty, Alain Badiou, and Félix Guattari. In so doing we seek to find between these practices points of both conjunction and disjunction which enrich our understanding of Cage’s and Deleuze’s work, and, more widely speaking, of the passage of twentieth century music and philosophy in general. Here we hope to make contributions to the fields of continental philosophy and music theory especially, and to open a point of engagement with the nascent field of sound studies. (shrink)

In this thesis, I develop and investigate various novel semantic frameworks for deontic logic. Deontic logic concerns the logical aspects of normative reasoning. In particular, it concerns reasoning about what is required, allowed and forbidden. I focus on two main issues: free-choice reasoning and the role of norms in deontic logic. -/- Free-choice reasoning concerns permissions and obligations that offer choices between different actions. Such permissions and obligations are typically expressed by a disjunctive clause in the scope of a (...) deontic operator. For instance, the sentence "Jane may take an apple or a pear" intuitively offers Jane a choice between two permitted courses of action: she may take an apple, and she may take a pear. In the first part of the thesis, I develop semantic frameworks for deontic logic that account for free-choice reasoning. I show that the resulting logics avoid problems that arise for other logical accounts of free-choice reasoning. The main technical contributions are completeness results for axiomatizations of the different logics. -/- Semantic frameworks for deontic logic typically only talk about norms implicitly. In the second part of the thesis, I clarify the role of norms in deontic logic. I develop a formal model of normative systems where norms are represented explicitly. The model takes into account both the hierarchical structure of normative systems, and the function of norms to regulate agent behavior. I show how the model can be used to clarify issues in the study of normative systems. I also develop a norm-based semantics for deontic action logic based on the model. (shrink)

This paper investigates the implicative conditional, a connective intended to describe the logical behavior of an empirically defined class of natural language conditionals, also named implicative conditionals, which excludes concessive and some other conditionals. The implicative conditional strengthens the strict conditional with the possibility of the antecedent and of the contradictory of the consequent. $${p\Rightarrow q}$$ p ⇒ q is thus defined as $${\lnot } \Diamond {(p \wedge \lnot q) \wedge } \Diamond {p \wedge } \Diamond {\lnot q}$$ ¬ ◊ (...) ( p ∧ ¬ q ) ∧ ◊ p ∧ ◊ ¬ q. We explore the logical properties of this conditional in a reflexive normal Kripke semantics, provide an axiomatic system and prove it to be sound and complete for our semantics. The implicative conditional validates transitivity and contraposition, which we take to be integral parts of reasoning and communication. But it only validates restricted versions of strengthening the antecedent, right weakening, simplification, and rational monotonicity. Apparent counterexamples to some of these properties are explained as due to contextual factors. Finally, the implicative conditional avoids the paradoxes of material and strict implication, and validates some connexive principles such as Aristotle’s theses and weak Boethius’ thesis, as well as some highly entrenched principles of conditionals, such as conjunction of consequents, disjunction of antecedents, modus ponens, cautious monotonicity and cut. (shrink)

We can contrast rationalising explanations of the form S φs because p with those of the form S φs because S believes that p. According the Common Kind View, the two sorts of explanation are the same. The Disjunctive View denies this. This paper sets out to elucidate the sense in which the Common Kind Theorist asserts, but the Disjunctivist denies, that the two explanations are the same. I suggest that, in the light of the distinction between kinds of explanation (...) and particular explanations, the relevant sameness thesis is ambiguous, thus giving us two distinct versions of the Common Kind View. I then argue that the only direct arguments for Disjunctivism available in the literature fail because they only succeed in undermining one version of the Common Kind View. I finish, however, by providing a fresh argument for the Disjunctive View which aims to undermine both versions of its competitor. (shrink)

Many have accepted that ordinary counterfactuals and might counterfactuals are duals. In this paper, I show that this thesis leads to paradoxical results when combined with a few different unorthodox yet increasingly popular theses, including the thesis that counterfactuals are strict conditionals. Given Duality and several other theses, we can quickly infer the validity of another paradoxical principle, ‘The Counterfactual Direct Argument’, which says that ‘A> ’ entails ‘A> ’. First, I provide a collapse theorem for the ‘counterfactual (...) direct argument’. The counterfactual direct argument entails the logical equivalence of the subjunctive and material conditional, given a variety of assumptions. Second, I provide a semantics that validates the counterfactual direct argument without collapse. This theory further develops extant dynamic accounts of conditionals. I give a new semantics for disjunction, on which A or B is only true in a context when A and B are both unsettled. The resulting framework validates CDA while invalidating other commonly accepted principles concerning the conditional and disjunction. (shrink)

Classical (Bayesian) probability (CP) theory has led to an influential research tradition for modeling cognitive processes. Cognitive scientists have been trained to work with CP principles for so long that it is hard even to imagine alternative ways to formalize probabilities. However, in physics, quantum probability (QP) theory has been the dominant probabilistic approach for nearly 100 years. Could QP theory provide us with any advantages in cognitive modeling as well? Note first that both CP and QP theory share the (...) fundamental assumption that it is possible to model cognition on the basis of formal, probabilistic principles. But why consider a QP approach? The answers are that (1) there are many well-established empirical findings (e.g., from the influential Tversky, Kahneman research tradition) that are hard to reconcile with CP principles; and (2) these same findings have natural and straightforward explanations with quantum principles. In QP theory, probabilistic assessment is often strongly context- and order-dependent, individual states can be superposition states (that are impossible to associate with specific values), and composite systems can be entangled (they cannot be decomposed into their subsystems). All these characteristics appear perplexing from a classical perspective. However, our thesis is that they provide a more accurate and powerful account of certain cognitive processes. We first introduce QP theory and illustrate its application with psychological examples. We then review empirical findings that motivate the use of quantum theory in cognitive theory, but also discuss ways in which QP and CP theories converge. Finally, we consider the implications of a QP theory approach to cognition for human rationality. (shrink)

Most, perhaps all, non-classical logics are a blend of classical logic with extralogical elements. Possibly this thesis has no general proof, and only a casuistic argument can be provided. I discuss a case of paraconsistency that results of applying a “filter” to two syllogistics. These syllogistics incorporate two ideas of Nikolai Vasiliev: the idea of a complete system of contrary judgements, and the idea of double judgements. I also show how these results can be extended to propositional logic, with (...) the aid of the conjunctive and disjunctive normal forms. Despite the non-classical appearance, it is used, without exception, the classical notion of deductive validity: a conclusion cannot carry more information, but may carry less information than the information carried by the collection of the premisses. (shrink)

A.N. Prior once showed that on certain apparently reasonable assumptions, a thesis sometimes associated with the name of Hume to the effect that no set of factual statements can ever entail an evaluative statement, is quite untenable. We assume only that there is at least one statement of each kind, and that the negation of a factual statement is factual — a principle we may call ‘N'. Now consider the disjunction F V E of some factual with some (...) evaluative statement. Since the disjunction is entailed by F, a factual statement, it must, if principle H is correct, be classified as factual. But by N, ∽ F is also factual, and this together with F V E entails E, thus violating H since E was exhypothesi an evaluative statement. (shrink)