280 research outputs found

    Imperative change and obligation to do

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    The ambition of the paper is to provide a solution to the problem posed by Von Wright (1999): how is it possible that the two actions, one of producing P and the other of preventing P can have different deontic status, the former being obligatory and the latter being forbidden. The solution for the problem is sought for by an investigation into connections between imperative and deontic logic. First, it is asked whether a solution could be found in Lemmon's (1965) system of "change logic", using his idea on connection between logic of orders being in force and deontic logic. The answer is the negative one. Next, the connection between Lemmon's imperative logic and deontic logic given in Aqvist's paper - "Next" and "Ought" (1965) - is analyzed. Than, the Lemmon's treatment of imperatives is restricted to the natural language imperatives and Aqvist's way of connecting imperative and deontic logic is modified accordingly. Some principles for the natural language imperatives are established (the negation rule ; the law of contraposition for imperative conditionals) and a simple "global" semantics is developed. The notion of "opposite action" is introduced and it is given an important role in semantics. Finally, a solution for von Wright's problem is given. In the closing sections some further topics for investigation are hinted: one of them being the connection between Aqvist's epistemic- imperative conception of interrogatives and "epistemic obligations", the other being formalization of the idea that imperatives create and re-create obligation patterns that can be described in deontic terms

    A Two-Dimensional Logic for Two Paradoxes of Deontic Modality

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    In this paper, we axiomatize the deontic logic in Fusco 2015, which uses a Stalnaker-inspired account of diagonal acceptance and a two-dimensional account of disjunction to treat Ross’s Paradox and the Puzzle of Free Choice Permission. On this account, disjunction-involving validities are a priori rather than necessary. We show how to axiomatize two-dimensional disjunction so that the introduction/elimination rules for boolean disjunction can be viewed as one-dimensional projections of more general two-dimensional rules. These completeness results help make explicit the restrictions Fusco’s account must place on free-choice inferences. They are also of independent interest, as they raise difficult questions about how to ‘lift’ a Kripke frame for a one- dimensional modal logic into two dimensions

    Questions, Presuppositions and Fallacies

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    [EN] In this paper I focus on the fallacy known as Complex Question or Many Ques tions. After a brief introduction, in Sect. 2 I highlight its pragmatic dimension, and in Sect. 3 its dialectical dimension. In Sect. 4 I present two accounts of this fallacy developed in argumentation theory, Douglas Walton’s and the Pragma-Dialectics’, which have resources to capture both its pragmatic and its dialectical nature. How ever, these accounts are unsatisfactory for various reasons. In Sect. 5 I focus on the pragmatic dimension of the fallacy and I suggest amendments to the accounts mentioned drawing on the study of the phenomenon of presupposition in theoretical pragmatics. I argue that the central notion in the defnition of the fallacy is that of an informative presupposition. In Sect. 6 I focus on the dialectical dimension of the fallacy. This dimension needs to be explicitly acknowledged in the defnition of the fallacy in order to distinguish it from a diferent, non-dialectical, fallacious argumentative move involving presuppositions.Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCLE

    Extracellular Blockade of K+ Channels by Tea: Results from Molecular Dynamics Simulations of the Kcsa Channel

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    TEA is a classical blocker of K+ channels. From mutagenesis studies, it has been shown that external blockade by TEA is strongly dependent upon the presence of aromatic residue at Shaker position 449 which is located near the extracellular entrance to the pore (Heginbotham, L., and R. MacKinnon. 1992. Neuron. 8:483–491). The data suggest that TEA interacts simultaneously with the aromatic residues of the four monomers. The determination of the 3-D structure of the KcsA channel using X-ray crystallography (Doyle, D.A., J.M. Cabral, R.A. Pfuetzner, A. Kuo, J.M. Gulbis, S.L. Cohen, B.T. Chait, and R. MacKinnon. 1998. Science. 280:69–77) has raised some issues that remain currently unresolved concerning the interpretation of these observations. In particular, the center of the Tyr82 side chains in KcsA (corresponding to position 449 in Shaker) forms a square of 11.8-Å side, a distance which is too large to allow simultaneous interactions of a TEA molecule with the four aromatic side chains. In this paper, the external blockade by TEA is explored by molecular dynamics simulations of an atomic model of KcsA in an explicit phospholipid bilayer with aqueous salt solution. It is observed, in qualitative accord with the experimental results, that TEA is stable when bound to the external side of the wild-type KcsA channel (with Tyr82), but is unstable when bound to a mutant channel in which the tyrosine residue has been substituted by a threonine. The free energy profile of TEA relative to the pore is calculated using umbrella sampling simulations to characterize quantitatively the extracellular blockade. It is found, in remarkable agreement with the experiment, that the TEA is more stably bound by 2.3 kcal/mol to the channel with four tyrosine residues. In the case of the wild-type KcsA channel, TEA (which has the shape of a flattened oblate spheroid) acts as an ideal plug blocking the pore. In contrast, it is considerably more off-centered and tilted in the case of the mutant channel. The enhanced stability conferred by the tyrosine residues does not arise from Π–cation interactions, but appears to be due to differences in the hydration structure of the TEA. Finally, it is shown that the experimentally observed voltage dependence of TEA block, which is traditionally interpreted in terms of the physical position of the TEA along the axis of the pore, must arise indirectly via coupling with the ions in the pore

    Counterfactuals as Strict Conditionals

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    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 diers 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

    Performatives and Imperatives

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    The term “performative” is used in at least two different senses. In the first sense, performatives are generatives, i.e. expres- sions by the use of which one creates new deontic states of affairs on the ground of extralinguistic conventions. In the sec- ond sense, performatives are operatives, i.e. expressions which contain verbal pred- icates and state their own utterances. In the article, both these types of expressions are compared to the class of imperatives which are characterized as expressions of the form “Let x see to it that p” and typ- ically express wishes. It is claimed that (1) only these imperatives are generatives which are uttered by deontic authorities, (2) no imperative is an operative sensu stricto; (3) imperative operatives are used instead of “pure” imperatives in order to emphasize the force of resolution

    Clause-Type, Force, and Normative Judgment in the Semantics of Imperatives

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    I argue that imperatives express contents that are both cognitively and semantically related to, but nevertheless distinct from, modal propositions. Imperatives, on this analysis, semantically encode features of planning that are modally specified. Uttering an imperative amounts to tokening this feature in discourse, and thereby proffering it for adoption by the audience. This analysis deals smoothly with the problems afflicting Portner's Dynamic Pragmatic account and Kaufmann's Modal account. It also suggests an appealing reorientation of clause-type theorizing, in which the cognitive act of updating on a typed sentence plays a central role in theorizing about both its semantics and role in discourse
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