The present contribution shows that a Hilbert-style axiomatization for dynamic logic of relation changers is complete for the standard Kripke semantics not by a well-known rewriting technique but by the idea of an auxiliary semantics studied by van Benthem and Wang et al. A key insight of our auxiliary semantics for dynamic logic of relation changers can be described as: “relation changers are bounded morphisms.” Moreover, we demonstrate that this semantic insight can be used to provide a modular cut-free labelled (...) sequent calculus for the logic in the sense that our calculus can be regarded as a natural expansion of a labelled sequent calculus of iteration-free propositional dynamic logic. (shrink)

This article is the second translation of the preface and first chapter of Hatano Seiichi's Time and Eternity. A full translation of the text, published by Suzuki Ichiro 鈴木一郎 in 1963, is not easily accessible to most readers, while an excellent partial translation by Joseph O'Leary has recently been made accessible to a wider audience through the monumental work, Japanese Philosophy: A Sourcebook. By providing a short historical introduction to both Hatano's life and works as a great thinker (...) and teacher, this article intends to supplement O'Leary's contribution and therefore enable more readers to gain access to the opening sections of Hatano's Time and Eternity. (shrink)

We develop intuitionistic public announcement logic over intuitionistic \({\textbf{K}}\), \({{\textbf{K}}}{{\textbf{T}}}\), \({{\textbf{K}}}{{\textbf{4}}}\), and \({{\textbf{S}}}{{\textbf{4}}}\) with distributed knowledge. We reveal that a recursion axiom for the distributed knowledge is _not_ valid for a frame class discussed in [ 12 ] but valid for the restricted frame class introduced in [ 20, 26 ]. The semantic completeness of the static logics for this restricted frame class is established via the concept of pseudo-model.

Abstract“The wrongness of Albert's action causally explains why Jane judged that his action was wrong”. This type of causal moral explanation has been extensively discussed in the recent metaethical literature. This paper motivates the following claims about this type of moral explanation. First, a typical defence of this type of moral explanation suggested in the literature does not work because it predicts inaccurate modal information. Second, focusing on different aspects of the ways moral judgements are generated provides better chances for (...) the defender of this type of moral explanation. Third, the strategy mentioned in the previous point leads us to the following alternative evaluative explanation: The property of being a harmful action explains a recognisable pattern of moral judgements observed in the relevant empirical studies. One crucial implication the paper alludes to is a localist approach to the debates concerning moral realism: We should consider each moral property's ontological genuineness separately, referring to specific empirical findings that are particularly relevant to the target moral property in question. Such a localist approach can provide solid resources for realists to respond to various anti‐realist challenges, such as an influential evolutionary debunking argument. (shrink)

The most famous chapter of Montesquieu’s _ The Spirit of the Laws _ (1748), Book XI, Chapter 6, 'On the constitution of England,' was an important i nspiration to the creators of modern constitutions, to which they often referred. However, as a result of scholarly focus on the political institutions discussed in this book, Montesquieu’s economic analysis has been woefully neglected. In order to correct this scholarly imbalance, this paper will elucidate the essential significance of Montesquieu’s comparison between the constitution (...) of modern England and that of ancient Rome in Book XI of _ The Spirit of the Laws _ ; inextricable relationship between military and political institutions on the one hand, and the transfer and distribution of wealth on the other. To argue this point, this paper will focus on Montesquieu’s other writings in the same year and shortly after the publication of _ The Spirit of the Laws _ : the revised edition in 1748 of _ The Considerations on the Causes of the Greatness of t... _. (shrink)

One influential positive argument for moral realism is the Explanatory Indispensability Argument. A crucial premise of this argument is the explanatory relevance of moral properties. On this premise, moral properties, such as wrongness, rightness, courage, and cowardice, are explanatorily indispensable to some empirical phenomena. Although there has been a lively debate on this premise, one crucial challenge to this thesis, what I call the Scientific Standard Challenge, has not been properly discussed. After explaining this challenge and a related concern, I (...) argue that in response to this central challenge, the proponents of the argument should take what I call the localist turn to defend the explanatory indispensability of moral properties. The localist turn encourages the defenders of moral explanations to be more sensitive to the nature of each moral explanation. For instance, some moral explanations are explanations of social matters, so the standards they need to meet are provided by relevant branches of the social sciences. On the other hand, some other moral explanations are about our psychology, so the theoretical standards those explanations need to meet should come from psychology. I illustrate how this localist project can be conducted in the case of the moral explanation that appeals to injustice. I argue that the field of comparative politics provides the theoretical standards moral explanations of institutional change need to meet. I shall then illustrate how a sophisticated moral explanation can meet those theoretical standards and how this moral explanation can be strong evidence of injustice’s explanatory indispensability. (shrink)

In this paper, using Mark Schroeder’s (2008a) expressivist semantic framework for normative language as a case study, I will identify difficulties that even an expressivist semantic theory capable of addressing the Frege-Geach problem will encounter in handling the logical possibility of moral dilemmas. To this end, I will draw on a classical puzzle formulated by McConnell (1978) that the logical possibility of moral dilemmas conflicts with some of the prima facie plausible axioms of the standard deontic logic, which include obligation (...) implies permission. On the tentative assumption that proponents of ethical expressivism should be generally committed to securing the logical possibility of moral dilemmas in their semantic theories, I will explore whether and how expressivists can successfully invalidate obligation implies permission within the framework developed by Schroeder. The case study eventually reveals that this can indeed be a hard task for expressivists. Generalizing from the case study, I will suggest that the source of the difficulty ultimately lies in the mentalist assumption of the expressivist semantic project that the logico-semantic relations exhibited by normative sentences should be modeled in terms of the psychological attitudes that speakers express by uttering them. My final goal will be to show that the difficulty expressivists face in dealing with the logical possibility of moral dilemmas is a reflection of the more general problem that their commitment to the mentalist assumption prevents them from flexibly adopting or dropping axioms in their semantic theories to get the right technical results. (shrink)

Although humans are endowed with domain-specific constraints for acquiring informal biology, its construction requires considerable experience with living things and their cultural representations. Less experienced adults may not know what constitutes generic species, and young children may rely on personification rather than category-based inference. Atran's postulate of the living-kind module that promptly produces universal folk taxonomy does not seem tenable.

朱子学は現代に生きる私たちにとって価値なきものなのだろうか? 儒教思想と近代的権利概念の親和性に着目、再検証を試みる。.

9th and 10th Nov. 2013 at Kyoto University. Organizers: Takeshi Sato and Shunsuke Sugimoto.

The logic CD is an intermediate logic which exactly corresponds to the Kripke models with constant domains. It is known that the logic CD has a Gentzen-type formulation called LD and rules are replaced by the corresponding intuitionistic rules) and that the cut-elimination theorem does not hold for LD. In this paper we present a modification of LD and prove the cut-elimination theorem for it. Moreover we prove a “weak” version of cut-elimination theorem for LD, saying that all “cuts” except (...) some special forms can be eliminated from a proof in LD. From these cut-elimination theorems we obtain some corollaries on syntactical properties of CD: fragments collapsing into intuitionistic logic. Harrop disjunction and existence properties, and a fact on the number of logical symbols in the axiom of CD. (shrink)

This article is the second translation of the preface and first chapter of Hatano Seiichi's Time and Eternity. A full translation of the text, published by Suzuki Ichiro 鈴木一郎 in 1963, is not easily accessible to most readers, while an excellent partial translation by Joseph O'Leary has recently been made accessible to a wider audience through the monumental work, Japanese Philosophy: A Sourcebook. By providing a short historical introduction to both Hatano's life and works as a great thinker (...) and teacher, this article intends to supplement O'Leary's contribution and therefore enable more readers to gain access to the opening sections of Hatano's Time and Eternity. (shrink)

The semilattice relevant logics ∪R, ∪T, ∪RW, and ∪TW are defined by semilattice models in which conjunction and disjunction are interpreted in a natural way. For each of them, there is a cut-free labelled sequent calculus with plural succedents . We prove that these systems are equivalent, with respect to provable formulas, to the restricted systems with single succedents . Moreover, using this equivalence, we give a new Hilbert-style axiomatizations for ∪R and ∪T and prove equivalence between two semantics for (...) the contractionless logics ∪RW and ∪TW. (shrink)

Barendregt gave a sound semantics of the simple type assignment system λ → by generalizing Tait’s proof of the strong normalization theorem. In this paper, we aim to extend the semantics so that the completeness theorem holds.

We establish the “contraction-elimination theorem” which means that if a sequent Γ A is provable in the implicational fragment of the Gentzen's sequent calculus LK and if it satisfies a certain condition on the number of the occurrences of propositional variables, then it is provable without the right contraction rule. By this theorem, we get the following.1. If an implicational formula A is a theorem of classical logic and is not a theorem of intuitionistic logic, then there is a propositional (...) variable which occurs at least once positively and at least twice negatively in A → a) → a).2. If an implicational formula A is a theorem of intuitionistic logic and is not a theorem of BCK-logic, then there is a propositional variable which occurs at least twice positively and at least once negatively in A → a → b).We prove the contraction-elimination theorem by a fully syntactical method, which has some analogy with Gentzen's cut-elimination. (shrink)