1. 315355.126059
    Consider this Thomistic-style doctrine: God’s believing that a contingent entity x exists is the cause of x’s existing. Let B be God’s believing that I exist. Then, either B exists in all possible worlds or B exists in all and only the worlds where I exist. …
    Found 3 days, 15 hours ago on Alexander Pruss's Blog
  2. 884266.126105
    In his article “Reassurance via Translation” Marcel Crabbe proposed a formalism to obtain reassurance and classical recapture in the setting of minimal F DE. His formalism proved to be general enough to be extended in order to formalize other forms of non-monotonic systems based on preference relations. It is the aim of this article to show how his result can be extended in a natural way by combining two different reasoning systems, namely minimal F DE and circumscription, in order to get a paraconsistent and paracomplete version of circumscription, which we will call paracomplistent circumscription, which has the advantages of F DE and circumscription but is neither explosive nor lacks modus ponens in consistent contexts. Furthermore, we will complete a proof Crabbe left unfinished.
    Found 1 week, 3 days ago on The Australasian Journal of Logic
  3. 1007037.126121
    J. D. Hamkins and M. Kikuchi, “The inclusion relations of the countable models of set theory are all isomorphic.” (manuscript under review)   Citation arχiv @ARTICLE{HamkinsKikuchi:The-inclusion-relations-of-the-countable-models-of-set-theory-are-all-isomorphic, author = {Joel David Hamkins and Makoto Kikuchi}, title = {The inclusion relations of the countable models of set theory are all isomorphic}, journal = {}, editor = {}, year = {}, volume = {}, number = {}, pages = {}, month = {}, doi = {}, note = {manuscript under review}, eprint = {1704.04480}, archivePrefix = {arXiv}, primaryClass = {math.LO}, url = {http://jdh.hamkins.org/inclusion-relations-are-all-isomorphic}, abstract = {}, keywords = {}, source = {}, } Abstract. …
    Found 1 week, 4 days ago on Joel David Hamkins's blog
  4. 1411016.12614
    This paper shows how to conservatively extend theories formulated in non-classical logics such as the Logic of Paradox, the Strong Kleene Logic and relevant logics with Skolem functions. Translations to and from the language extended by Skolem functions into the original one are presented and shown to preserve derivability. It is also shown that one may not always substitute s ˙= fA(¯t) and A(¯t, s) even though A( ¯x, y) determines the extension of a function.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  5. 1461002.126168
    We provide a sufficient frame-theoretic condition for a super-bi-intuitionistic logic to have Maksimova’s variable separation property. We conclude that bi-intuitionistic logic enjoys the property. Furthermore, we offer an algebraic characterization of the super-bi-intuitionistic logics with Maksimova’s property.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  6. 1461020.126243
    This paper reflects on metametaphysics and as such develops a metametameta-physical view: that quietist metametaphysics requires dialetheism, and in turn a paraconsistent logic. I demonstrate this using Carnap’s metametaphysical position in his ‘Empiricism, Semantics and Ontology’ (1950) as an example, with regard to how it exhibits self-reference and results in inconsistency. I show how applying Carnap’s position to itself produces a dilemma, both horns of which lead to a contradiction. Such inconsistency commonly arises from meta-theories with global scope, as the ‘meta’ approach aims to transcend the scope of that which it is theorizing about, whilst the global nature will place itself back within the scope of that which it is theorizing about, which together result in the theory referring to itself whilst refuting itself. I argue that any global metametaphysical theory that draws a limit to thought will face self-reference problems leading to contradictory realms. My conclusion is conditional: If we want to meta-philosophize in such a way and treat quietist meta-theories as being true, then we need to be dialetheist and utilize a paraconsistent logic in order to accommodate the contradictions that result from such theorizing.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  7. 1461058.126269
    A theorem from Archimedes on the area of a circle is proved in a setting where some inconsistency is permissible, by using paraconsistent reasoning. The new proof emphasizes that the famous method of exhaustion gives approximations of areas closer than any consistent quantity. This is equivalent to the classical theorem in a classical context, but not in a context where it is possible that there are inconsistent infinitesimals. The area of the circle is taken ‘up to inconsistency’. The fact that the core of Archimedes’s proof still works in a weaker logic is evidence that the integral calculus and analysis more generally are still practicable even in the event of inconsistency.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  8. 1461118.126293
    This paper investigates the use of neighborhood frames as a semantics for the logics of unknown truths and related non-normal epistemic systems, including the logic of false beliefs. However, the interest in these logics is not restricted to epistemic settings. As such, this paper is perhaps better viewed as a continuation of the study of reflexive-insensitive logics (we borrow this terminology from [3]) that was initiated in [5] and further developed in [7] and [3]. In addition to this more systematic motive, it is also our desire to further elucidate (and exploit, in some cases) the connections between these logics and provability logics.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  9. 1461184.126322
    Circular definitions have primarily been studied in revision theory in the classical scheme. I present systems of circular definitions in the Strong Kleene and supervaluation schemes and provide complete proof systems for them. One class of definitions, the intrinsic definitions, naturally arises in both schemes. I survey some of the features of this class of definitions.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  10. 1461206.12635
    In recent years, two non-classical views about negation have gained considerable traction in the philosophical literature. The paracomplete view holds that excluded middle (EM) is invalid, while the paraconsistent view holds that explosion (EX) is invalid. Both run contrary to classical logic in distinct but dual ways.
    Found 2 weeks, 2 days ago on The Australasian Journal of Logic
  11. 1525812.126379
    If $M$ is a model of ZFC set theory, let $I$ be the definable cut of its ordinals, the collection of ordinals that are below an ordinal $\delta$ of $M$ that is definable in $M$ without parameters. This would include all the ordinals of $M$, if the definable ordinals happen to be unbounded in $M$, but one can also construct examples where the definable cut is bounded in $M$. …
    Found 2 weeks, 3 days ago on Joel David Hamkins's blog
  12. 1691756.12641
    One of the central logical ideas in Wittgenstein’s Tractatus logicophilosophicus is the elimination of the identity sign in favor of the so-called “exclusive interpretation” of names and quantifiers requiring different names to refer to different objects and (roughly) different variables to take different values. In this paper, we examine a recent development of these ideas in papers by Kai Wehmeier. We diagnose two main problems of Wehmeier’s account, the first concerning the treatment of individual constants, the second concerning so-called “pseudo-propositions” (Scheinsatze) of classical logic such as a = a or a = b ∧ b = c → a = c. We argue that overcoming these problems requires two fairly drastic departures from Wehmeier’s account: (1) Not every formula of classical first-order logic will be translatable into a single formula of Wittgenstein’s exclusive notation. Instead, there will often be a multiplicity of possible translations, revealing the original “inclusive” formulas to be ambiguous. (2) Certain formulas of first-order logic such as a = a will not be translatable into Wittgenstein’s notation at all, being thereby revealed as nonsensical pseudo-propositions which should be excluded from a “correct” conceptual notation. We provide translation procedures from inclusive quantifier-free logic into the exclusive notation that take these modifications into account and define a notion of logical equivalence suitable for assessing these translations.
    Found 2 weeks, 5 days ago on PhilSci Archive
  13. 2268321.12649
    In this paper, I examine the relationship between physical quantities and physical states in quantum theories. I argue against the claim made by Arageorgis (1995) that the approach to interpreting quantum theories known as Algebraic Imperialism allows for “too many states”. I prove a result establishing that the Algebraic Imperialist has very general resources that she can employ to change her abstract algebra of quantities in order to rule out unphysical states.
    Found 3 weeks, 5 days ago on PhilSci Archive
  14. 2584334.126514
    In response to G.Belot’s (2013) criticism that Bayesian theory is epistemologically immodest, we argue that his analysis is misguided. The topological conditions that we understand underpin his criticisms of familiar results about asymptotic Bayesian conditioning are self-defeating. They require extreme a priori credences regarding, e.g., the limiting behavior of observed relative frequencies. Instead, we offer a rival explication of Bayesian modesty: Rival scientific opinions should be responsive to new facts as a way to resolve their disputes. Using a result of Blackwell and Dubins (1962), we explain how amenability to new evidence may serve as the basis for resolving conflicts among Bayesian investigators. When the new evidence fails to achieve a resolution, that failure can identify epistemologically immodest Bayesian credal states. Also we assess A. Elga’s (2016) rebuttal to Belot’s analysis. He focuses attention on the role that the assumption of countable additivity plays in Belot’s criticism of asymptotic Bayesian learning.
    Found 4 weeks, 1 day ago on Teddy Seidenfeld's site
  15. 2674145.126531
    Let me tell you about a fascinating paradox arising in certain infinitary two-player games of perfect information. The paradox, namely, is that there are games for which our judgement of who has a winning strategy or not depends on whether we insist that the players play according to a deterministic computable procedure. …
    Found 1 month ago on Joel David Hamkins's blog
  16. 2724800.126545
    Truth values have been put to quite different uses in philosophy and logic, being characterized, for example, as: primitive abstract objects denoted by sentences in natural and formal languages, abstract entities hypostatized as the equivalence classes of sentences, what is aimed at in judgements, values indicating the degree of truth of sentences, entities that can be used to explain the vagueness of concepts, values that are preserved in valid inferences, values that convey information concerning a given proposition. Depending on their particular use, truth values have been treated as unanalyzed, as defined, as unstructured, or as structured entities.
    Found 1 month ago on Stanford Encyclopedia of Philosophy
  17. 2955542.126559
    Hybrid logics are logics that result by adding further expressive power to ordinary modal logic. The most basic hybrid logic is obtained by adding so-called nominals which are propositional symbols of a new sort, each being true at exactly one possible world. The history of hybrid logic goes back to Arthur N. Prior’s work in the 1960s.
    Found 1 month ago on Stanford Encyclopedia of Philosophy
  18. 3520927.126572
    In philosophy of statistics, Deborah Mayo and Aris Spanos have championed the following epistemic principle, which applies to frequentist tests: Severity Principle (full). Data x (produced by process G) provides good evidence for hypothesis H (just) to the extent that test T severely passes H with x . (Mayo and Spanos 2011, pp.162). They have also devised a severity score that is meant to measure the strength of the evidence by quantifying the degree of severity with which H passes the test T (Mayo and Spanos 2006, 2011; Spanos 2013). That score is a real number defined on the interval [0,1]. In this paper, I put forward a paradoxical feature of the severity score as a measure of evidence. To do this, I create a scenario where a frequentist statistician S is interested in finding out if there is a difference between the means of two normally distributed random variables. The null hypothesis (H0) states that there is no difference between the two means.
    Found 1 month, 1 week ago on PhilSci Archive
  19. 3646210.126585
    Today’s Virtual Colloquium is “Global and Local Atheisms” by Jeanine Diller. Dr. Diller received her PhD from the University of Michigan and is currently an assistant professor in the Department of Philosophy and Program on Religious Studies of the University of Toledo in Ohio. …
    Found 1 month, 1 week ago on The Prosblogion
  20. 3693882.126603
    I propose a new definition of identification in the limit (also called convergence to the truth), as a new success criterion that is meant to complement, rather than replacing, the classic definition due to Gold (1967). The new definition is designed to explain how it is possible to have successful learning in a kind of scenario that Gold’s classic account ignores—the kind of scenario in which the entire infinite data stream to be presented incrementally to the learner is not presupposed to completely determine the correct learning target. From a purely mathematical point of view, the new definition employs a convergence concept that generalizes net convergence and sits in between pointwise convergence and uniform convergence. Two results are proved to suggest that the new definition provides a success criterion that is by no means weak: (i) Between the new identification in the limit and Gold’s classic one, neither implies the other. (ii) If a learning method identifies the correct target in the limit in the new sense, any U-shaped learning involved therein has to be redundant and can be removed while maintaining the new kind of identification in the limit. I conclude that we should have (at least) two success criteria that correspond to two senses of identification in the limit: the classic one and the one proposed here. They are complementary: meeting any one of the two is good; meeting both at the same time, if possible, is even better.
    Found 1 month, 1 week ago on PhilSci Archive
  21. 3751483.126617
    In this work we present a dynamical approach to quantum logics. By changing the standard formalism of quantum mechanics to allow non-Hermitian operators as generators of time evolution, we address the question of how can logics evolve in time. In this way, we describe formally how a non-Boolean algebra may become a Boolean one under certain conditions. We present some simple models which illustrate this transition and develop a new quantum logical formalism based in complex spectral resolutions, a notion that we introduce in order to cope with the temporal aspect of the logical structure of quantum theory.
    Found 1 month, 1 week ago on PhilSci Archive
  22. 3751499.12663
    We discuss generalized pobabilistic models for which states not necessarily obey Kolmogorov’s axioms of probability. We study the relationship between properties and probabilistic measures in this setting, and explore some possible interpretations of these measures.
    Found 1 month, 1 week ago on PhilSci Archive
  23. 3959027.126643
    There was a period in the 1970’s when the admissions data for the UC–Berkeley graduate school (hereafter, BGS) exhibited some (prima facie) peculiar statistical correlations. Specifically, a strong negative correlation was observed between being female and being accepted into BGS. This negative correlation (in the overall population of BGS applicants) was (initially) a cause for some concern regarding the possibility of gender bias in the admissions process at BGS. However, closer scrutiny of the BGS admissions data from this period revealed that no individual department’s admissions data exhibited a negative correlation between being female and being admitted. In fact, every department reported a positive correlation between being female and being accepted. In other words, a correlation that appears at the level of the general population of BGS applicants is reversed in every single department of BGS. This sort of correlation reversal is known as Simpson’s Paradox. Because admissions decisions at BGS are made (autonomously) by each individual department, the lack of departmental correlations seems to rule-out the gender bias hypothesis as the best (causal) explanation of the observed correlations in the data. As it happens, there was a strong positive correlation between being female and applying to a department with a (relatively) high rejection rate.
    Found 1 month, 2 weeks ago on Branden Fitelson's site
  24. 4199535.126656
    It was, I think, till recently broadly assumed among working analytic metaphysicians that metaphysics, or at least that branch of it called ontology, is concerned with issues of existence, and that one’s known arguments that one can resist positing Meinongian unreal objects by accepting his theory of descriptions. However, it would be a mistake to read Russell as nothing more than a proto-Quinean. This will no doubt already be conceded for the period of Russell’s career in which he thought there were notions of “existence” not explicable by means of the existential quantifier, or embraced a distinction between existence and mere being or subsistence (e.g., PoM §427, Papers 4, 486–89, PP 100). However, in what follows I want to argue that this is true even for mature Russell, during the period (starting roughly 1913) in which he officially held the position that all existence claims are to be understood quantificationally. In particular, metaphysical position is more or less exhausted by one’s position on while mature Russell understood “Fs exist” as expressing p(∃v)Fvq, the question of what entities there are, or what entities exist. This he would not have taken the truth of this claim necessarily to set-likely stemmed from Quine’s well-known paper “On What There Is”, tle the metaphysical or ontological status of Fs. Russell had, run-views is determined by what things its quantifiers range over: “To be is to be the value of a variable,” as he succinctly put it (Quine 1948, 15). Of course, Quine’s views were never universal, but at least most ning alongside his account of existence, a conception of belonging to what is, as he variously put it, “ultimate,” “fundamental”, the “bricks of the universe”, the “furniture of the world”, something “really there”.
    Found 1 month, 2 weeks ago on Kevin C. Klement's site
  25. 4436705.126669
    We consider a natural-language sentence that cannot be formally represented in a first-order language for epistemic two-dimensional semantics. We also prove this claim in the appendix. It turns out, however, that the most natural ways to repair the expressive inadequacy of the first-order language render moot the original philosophical motivation of formalizing a priori knowability as necessity along the diagonal. In this paper we investigate some questions concerning the expressive power of a first-order modal language with two-dimensional operators. In particular, a language endowed with a two-dimensional semantics intended to provide a logical analysis of the discourse involving a priori knowledge. We consider a natural-language sentence that cannot be formally represented in such a language. This was firstly conjectured in Lampert (manuscript), but here we present a proof. It turns out, however, that the most natural ways to repair this expressive inadequacy render moot the original philosophical motivation of formalizing a priori knowability as necessity along the diagonal.
    Found 1 month, 3 weeks ago on PhilPapers
  26. 4500651.126682
    Traditional monotheism has long faced logical puzzles (omniscience, omnipotence, and more) [10, 11, 13, 14]. We present a simple but plausible ‘gappy’ framework for addressing these puzzles. By way of illustration we focus on God’s alleged stone problem. What we say about the stone problem generalizes to other familiar ‘paradoxes of omni- properties’, though we leave the generalization implicit. We assume familiarity with the proposed (subclassical) logic but an appendix is offered as a brief review.
    Found 1 month, 3 weeks ago on Aaron J Cotnoir's site
  27. 4675395.126695
    Is part of a perfectly natural, or fundamental, relation? Philosophers have been hesitant to take a stand on this issue. One of reason for this hesitancy is the worry that, if parthood is perfectly natural, then the perfectly natural properties and relations are not suitably “independent” of one another. (Roughly, the perfectly natural properties are not suitably independent if there are necessary connections among them.) In this paper, I argue that parthood is a perfectly natural relation. In so doing, I argue that this “independence” worry is unfounded. I conclude by noting some consequences of the naturalness of parthood.
    Found 1 month, 3 weeks ago on Maya Eddon's site
  28. 4681614.126708
    We prove that under some technical assumptions on a general, non-classical probability space, the probability space is extendible into a larger probability space that is common cause closed in the sense of containing a common cause of every correlation between elements in the space. It is argued that the philosophical significance of this common cause completability result is that it allows the defence of the Common Cause Principle against certain attempts of falsification. Some open problems concerning possible strengthening of the common cause completability result are formulated.
    Found 1 month, 3 weeks ago on PhilSci Archive
  29. 4688270.126721
    Let me tell you about the game Buckets of fish. This is a two-player game played with finitely many buckets in a line on the beach, each containing a finite number of fish. There is also a large supply of additional fish available nearby, fresh off the boats. …
    Found 1 month, 3 weeks ago on Joel David Hamkins's blog
  30. 5000922.126739
    We offer a defense of one aspect of Paul Horwich’s response to the Liar paradox—more specifically, of his move to preserve classical logic. Horwich’s response requires that the full intersubstitutivity of ‘ ‘A’ is true’ and A be abandoned. It is thus open to the objection, due to Hartry Field, that it undermines the generalization function of truth. We defend Horwich’s move by isolating the grade of intersubstitutivity required by the generalization function and by providing a new reading of the biconditionals of the form “ ‘A’ is true iff A.”
    Found 1 month, 3 weeks ago on Anil Gupta's site