Most publications are available on-line.
Abstract. In this doctoral dissertation, three topics from the philosophy of mind (Aristotle's account of reflective awareness, Wittgenstein's early philosophy of mind, and Lévy-Bruhl's thesis of logical relativism) are clarified with the help of modern epistemic, modal and perceptual logic.
Abstract. Some years ago, Lokhorst proposed an intuitionistic reformulation of Mally's deontic logic (1926). This reformulation was unsatisfactory, because it provided a striking theorem that Mally himself did not mention. In this paper, we present an alternative reformulation of Mally's deontic logic that does not provide this theorem.
Abstract. We discuss three aspects of the intuitionistic reformulation of Mally's deontic logic that was recently proposed (Journal of Philosophical Logic (2013) 42:635-641). First, this reformulation is more similar to Standard Deontic Logic than appears at first sight: like Standard Deontic Logic, it is Kanger reducible and Anderson reducible to alethic logic and it has a semantical interpretation that can be read in deontic terms. Second, this reformulation has an extension that provides 100% of the theorems stated by Mally himself (and that does not provide O A -> A, which Mally himself did not state either). Third, it is interesting to view Mally's original deontic logic as an extension of this reformulation.
Abstract. In 1926, Ernst Mally proposed a number of deontic postulates. He added them as axioms to classical propositional logic. The resulting system was unsatisfactory because it had the consequence that A is the case if and only if it is obligatory that A. We present an intuitionistic reformulation of Mally's deontic logic. We show that this system does not provide the just-mentioned objectionable theorem while most of the theorems that Mally considered acceptable are still derivable. The resulting system is unacceptable as a deontic logic, but it does make sense as a lax logic in the modern sense of the word.
Abstract. This is a report on the 3-day workshop The Neuroscience of Responsibility that was held in the Philosophy Department at Delft University of Technology in The Netherlands during February 11th-13th, 2010. The workshop had 25 participants from The Netherlands, Germany, Italy, UK, USA, Canada and Australia, with expertise in philosophy, neuroscience, psychology, psychiatry and law. Its aim was to identify current trends in neurolaw research related specifically to the topic of responsibility, and to foster international collaborative research on this topic. The workshop agenda was constructed by the participants at the start of each day by surveying the topics of greatest interest and relevance to participants. In what follows, we summarize (1) the questions which participants identified as most important for future research in this field, (2) the most prominent themes that emerged from the discussions, and (3) the two main international collaborative research project plans that came out of this meeting.
Abstract. In 1926, Ernst Mally proposed the first system of deontic logic. His system turned out to be unacceptable. How can it be repaired? We discuss several proposals to reformulate it in terms of strict implication, relevant implication and strict relevant implication.
Abstract. We present axiomatizations of the deontic fragment of Anderson's relevant deontic logic (the logic of obligation and related concepts) and the eubouliatic fragment of Anderson's eubouliatic logic (the logic of prudence, safety, risk, and related concepts).
Abstract. Several systems of monadic deontic logic are defined in terms of systems of alethic modal logic with a propositional constant. When the universal propositional quantifier is added to these systems, the propositional constant becomes definable in terms of the deontic operator. As a result, the meaning of this constant becomes clearer and it becomes easy to axiomatize the deontic fragments of the alethic modal systems.
Abstract. In 1926, Mally presented the first formal system of deontic logic. His system had several consequences which Mally regarded as surprising but defensible. It also, however, has the consequence that A is obligatory if and only if A is the case, which is unacceptable from the point of view of any reasonable deontic logic. We describe Mally's system and discuss how it might reasonably be repaired.
Abstract. We provide a description and informal analysis of the commonalities in moral discourse concerning issues in the field of information and communications technology, present a logic model (DEAL) of this type of moral discourse which makes use of recent research in deontic, epistemic and action logic, and indicate--drawing upon recent research in computer implementations of modal logic--how information systems may be developed that implement the proposed formalization.
Abstract. In 1926, Mally presented the first formal system of deontic logic. His system had several consequences which Mally regarded as surprising but defensible. It also had a consequence (A is obligatory if and only if A is the case) which Menger (1939) and almost all later deontic logicians have regarded as unacceptable. We give an exposition of Mally's system and discuss how it may be repaired.
Abstract. René Descartes thought that the pineal gland is the part of the body with which the soul is most immediately associated. Several prominent historians (such as Soury, Thorndike and Sherrington) have claimed that this idea was not very original. We re-examine the evidence and conclude that their assessment was wrong. We pay special attention to the thesis about the pineal gland which Jean Cousin defended in January, 1641.
Abstract. In 1926, Ernst Mally proposed the first formal deontic system. As Mally and others soon realized, this system had some rather strange consequences. We show that the strangeness of Mally's system is not so much due to his informal deontic principles as to the fact that he formalized those principles in terms of the propositional calculus. If they are formalized in terms of relevant logic rather than classical logic, one obtains a system which is related to Anderson's relevant deontic logic and not nearly as strange as Mally's own system.
Abstract. We show that Peter Geach's ideas on deontic quantification or deontic abstraction (Philosophia 11 (1981) 1-12) pose no threat to the standard modal approach to deontic logic. They can very well be represented within the framework of a standard quantified deontic system equipped with an alethic abstraction operator.
Abstract. We explicate the thesis of logical relativism (people of different cultures may have different logics) in logical terms. Our illustrations come from the field of paraconsistent logic.
Abstract. We describe a new way in which theories about the deontic status of actions can be represented in terms of the standard two-sorted first-order extensional predicate calculus. Some of the resulting formal theories are easy to implement in Prolog; one prototype implementation--R. M. Lee's deontic expert shell DX--is briefly described.
Abstract. This paper supersedes the author's "An ancient Greek theory of hemispheric specialization," Clio Medica 17 (1982) 33-38. It is argued that the ancient Greek theory about functional cerebral asymmetry discussed in that article can hardly have been put forward before the third century B. C. It should therefore not be attributed to Diocles of Carystus (fourth century B. C.).
Abstract. Using Fagin's and Halpern's local reasoning models and an epistemic variant of Jennings's and Schotch's semantics of weakly aggregative modal logic, we argue that the hypothesis that split-brain patients have two coherent minds is preferable to the hypothesis that they have one incoherent mind.
Abstract. We present a logical reconstruction of Aristotle's views on reflective awareness (De Anima III.2, 425b12-25, and De Somno 2, 455a12-22).
Abstract. Tractatus 5.542-5.5421 should be read as follows: anything which represents is complex; the soul is simple; so `the superficial psychologists of the present day' are mistaken when claiming that the soul represents anything. In contrast to the `empirical self', with which psychology is concerned, the `metaphysical' or `transcendental' soul, subject, or self is a purely fictitious entity (or rather, non-entity) which does not have any positive function.
Abstract. How should our logic express what other logics deem necessary? How should we give a rational account of forms of rationality which are different from ours? The present paper answers these questions. It shows how to enrich logical systems with operators which describe what is necessary, rational and imaginary according to other systems. Although only Da Costa's paraconsistent calculi are treated in detail, the construction is generally applicable. As a result, the thesis of logical relativism--people from different cultures may live in different cognizable worlds--may henceforth be discussed in terms of modal logic and possible world semantics.
Abstract. This paper presents a formal explication of Wittgenstein's early views on ontology, the syntax and semantics of an ideal logical language, and the propositional attitudes. It is shown that Wittgenstein gave a "language of thought" analysis of propositional attitude ascriptions and that his ontological views imply that such ascriptions are truth-functions of (and supervenient upon) elementary sentences. Finally, an axiomatization of a quantified doxastic modal logic corresponding to Tractarian semantics is given.
Abstract. In order to study the modal status of antinomies (provable contradictions), we present two modal extensions of the antinomic calculus proposed by F.G. Asenjo and J. Tamburino in their "Logic of antinomies," Notre Dame Journal of Formal Logic 16 (1975), pp. 17-44. Both systems are proved to be absolutely consistent and to be sound and complete with respect to certain Kripke-style models. It is shown that antinomies are both necessary and impossible in any case. They are provably contingent as well when serial accessibility relations between possible worlds are assumed.
Abstract. The purpose of this paper is twofold. First, I want to point out that Wittgenstein's Tractatus contains a clear and remarkably modern example of a theory of supervenience. And secondly, I want to argue that this theory of supervenience may be interpreted as a weak form of a principle of truth-functionality--which may exactly be the form of this principle which Wittgenstein himself had in mind.
Abstract. Deontic logic is the logic of obligation, permission and prohibition. Linear logic is a resource conscious logic which is well-known within computer science. Petri nets are models of concurrent dynamic processes which have been used in hundreds of applications. In this paper, we present a deontic linear system with Petri net semantics. This system has two advantages over modal and relevantist deontic logic: (1) it is free from many of the so-called "paradoxes" which plague the latter approaches; (2) its semantics are related to modelling techniques which are actually used in practice.
Abstract. This book contains the following three previously unpublished essays by Hector-Neri Castañeda: (1) Quine's experiment with intensional objects and his existentialist quantified modal logic; (2) Supervenient properties, emergence, and the hierarchy of concrete individuals; (3) Indexical reference and causal diagrams in intentional action. It also contains a bibliography of Castañeda's philosophical publications from 1986 to 1990.
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