The present monograph is a slightly revised version of my Habilitations schrift Proof-theoretic Aspects of Intensional and Non-Classical Logics, successfully defended at Leipzig University, November 1997. It collects work on proof systems for modal and constructive logics I have done over the last few years. The main concern is display logic, a certain refinement of Gentzen's sequent calculus developed by Nuel D. Belnap. This book is far from offering a comprehensive presentation of generalized sequent systems for modal logics broadly conceived. (...) The proof-theory of non-classical logics is a rapidly developing field, and even the generalizations of the ordinary notion of sequent listed in Chapter 1 can hardly be presented in great detail within a single volume. In addition to further investigating the various approaches toward generalized Gentzen systems, it is important to compare them and to discuss their relative advantages and disadvantages. An initial attempt at bringing together work on different kinds of proof systems for modal logics has been made in [188]. Another step in the same direction is [196]. Since Chapter 1 contains introductory considerations and, moreover, every remaining chapter begins with some surveying or summarizing remarks, in this preface I shall only emphasize a relation to philosophy that is important to me, register the sources of papers that have entered this book in some form or another, and acknowledge advice and support. (shrink)

In this paper, a family of paraconsistent propositional logics with constructive negation, constructive implication, and constructive co-implication is introduced. Although some fragments of these logics are known from the literature and although these logics emerge quite naturally, it seems that none of them has been considered so far. A relational possible worlds semantics as well as sound and complete display sequent calculi for the logics under consideration are presented.

This chapter is concerned with logical aspects of negation, i.e. with the role of negation in valid inferences and hence with the contribution negation makes to the truth and falsity conditions of declarative expressions. Negation is an important philosophical and logical concept. Often differences between logical systems can ‐ at least partially ‐ be described as differences between the notions of negation used in these logics.

According to Suszko’s Thesis, there are but two logical values, true and false. In this paper, R. Suszko’s, G. Malinowski’s, and M. Tsuji’s analyses of logical twovaluedness are critically discussed. Another analysis is presented, which favors a notion of a logical system as encompassing possibly more than one consequence relation. [A] fundamental problem concerning many-valuedness is to know what it really is. [13, p. 281].

The topic of identity of proofs was put on the agenda of general (or structural) proof theory at an early stage. The relevant question is: When are the differences between two distinct proofs (understood as linguistic entities, proof figures) of one and the same formula so inessential that it is justified to identify the two proofs? The paper addresses another question: When are the differences between two distinct formulas so inessential that these formulas admit of identical proofs? The question appears (...) to be especially natural if the idea of working with more than one kind of derivations is taken seriously. If a distinction is drawn between proofs and disproofs (or refutations) as primitive entities, it is quite conceivable that a proof of one formula amounts to a disproof of another formula, and vice versa. A notion of inherited identity of derivations is introduced for derivations in a cut-free sequent system for Almukdad and Nelson’s constructive paraconsistent logic N4 with strong negation. The notion is obtained by identifying sequent rules the application of which has no effect on the identity of derivations. Then the notion of inherited identity is used to define a bilateralist notion of synonymy between formulas, which is a relation drawing more fine-grained distinctions between formulas than strong equivalence. (shrink)

This paper deals with various substructural propositional logics, in particular with substructural subsystems of Nelson's constructive propositional logics N– and N. Doen's groupoid semantics is extended to these constructive systems and is provided with an informational interpretation in terms of information pieces and operations on information pieces.

Curry’s paradox is well known. The original version employed a conditional connective, and is not forthcoming if the conditional does not satisfy contraction. A newer version uses a validity predicate, instead of a conditional, and is not forthcoming if validity does not satisfy structural contraction. But there is a variation of the paradox which uses “external validity”. And since external validity contracts, one might expect the appropriate version of the Curry paradox to be inescapable. In this paper we show that (...) this is not the case. We consider two ways of formalising the notion of external validity, and show that in both of these the paradox is not forthcoming without the appropriate forms of contraction. (shrink)

A prominent issue in mainstream epistemology is the controversy about doxastic obligations and doxastic voluntarism. In the present paper it is argued that this discussion can benefit from forging links with formal epistemology, namely the combined modal logic of belief, agency, and obligation. A stit-theory-based semantics for deontic doxastic logic is suggested, and it is claimed that this is helpful and illuminating in dealing with the mentioned intricate and important problems from mainstream epistemology. Moreover, it is argued that this linking (...) is of mutual benefit. The discussion of doxastic voluntarism directs the attention of doxastic logicians to the notion of belief formation and thus to dynamic aspects of beliefs that have hitherto been neglected. The development of a formal language and semantics for ascriptions of belief formation may contribute to clarifying the contents and the implications of voluntaristic claims. A simple observation concerning other-agent nestings of stit-operators, for instance, may help illuminating the notions of making belief and responsibility for beliefs of others. In this way, stit-theory may serve as a bridge between mainstream and formal epistemology. (shrink)

The paper provides a uniform Gentzen-style proof-theoretic framework for various subsystems of classical predicate logic. In particular, predicate logics obtained by adopting van Behthem''s modal perspective on first-order logic are considered. The Gentzen systems for these logics augment Belnap''s display logic by introduction rules for the existential and the universal quantifier. These rules for x and x are analogous to the display introduction rules for the modal operators and and do not themselves allow the Barcan formula or its converse to (...) be derived. En route from the minimal modal predicate logic to full first-order logic, axiomatic extensions are captured by purely structural sequent rules. (shrink)

The purpose of this article is to illustrate the role of sociology in the field of corporate social responsibility. It presents a case study conducted by a research group consisting of two University partners in association with a Swiss SME. This project attempted to draw conclusions from a specific sociological consultancy research project on the general possibilities and opportunities of sociology in applied research and operational sustainability consulting. On the basis of the project findings, the article reflects on the extent (...) to which sociology could profitably intervene, on the limitations for sociological research and consultations in this field and on the conclusions that can be drawn for future analyses. (shrink)

The article presents the catechumenal theology of St. Ambrose and St. Augustine, highlighting in the former, four elements proper to the baptismal itinerary of Milan, such as the agonistic character of the baptismal preparation, the biblical catechesis related to the biblical characters of the Old Testament, the virtues and the rite of the Effetá. Thirdly, the importance of the Traditio Symboli in Milan with its theology is highlighted, and finally the secret that St. Ambrose kept on the rites of Christian (...) initiation, in order to arise curiosity in those who were going to receive them. Subsequently, the theology of two rites belonging to the Easter Vigil, namely, the washing of the feet and the post-baptismal anointing with myrum, is discussed. The second part of the article, presents the Augustinian theology of the catechumenate, stressing three elements of the catechumenal process, namely, the fasting and other ascetic practices, the traditio symboli and the traditio orationis. On the post-baptismal rites the article emphasises the Eucharistic catechesis preached on Easter Sunday with its special characteristics and the final procession that was done on the last day of the Easter Week to a memoria martyrum. (shrink)

[1. Heft]. Beiträge von Kolloquien des Arbeitskreises Philosophie-Naturwissenschaften, insbesondere vom 31. 5. und 7. 6. 1972.--2. Heft. Beiträge von der wissenschaftlichen Tagung des Arbeitskreises Philosophie-Naturwissenschaften am 9. und 10. April 1974. v.

In this paper functional completeness results are obtained for certain positive and constructive propositional logics associated with a Tarski-type structured consequence relation as defined by Gabbay.

Band 9 der Schriftenreihe Beitrage zur Angewandten Ethik versammelt Arbeiten zu aktuellen Problemen sowie zu Grundlagenfragen der Medizinischen Ethik. Es handelt sich dabei zum Teil um Beitrage zu wissenschaftlichen Symposien, die das Interuniversitare Institut fur Angewandte Ethik in den Jahren 2008-2011 veranstaltet hat, und zum anderen Teil um Forschungsarbeiten, die im Rahmen von Projekten dieses Instituts entstanden sind. Zu den aktuellen Problemen der Medizinischen Ethik, die in den einzelnen Beitragen angeschnitten werden, gehoren Fragen der Stammzellenforschung und der Praimplantationsdiagnostik ebenso wie (...) Fragen, die sich im Zusammenhang mit den bei der In-Vitro-Fertilisation entstehenden 'uberzahligen' Embryonen ergeben, sowie Fragen bezuglich der neuen Patientenverfugungen - also durchwegs Fragen von hochster Aktualitat und Brisanz. (shrink)

Herophilus, a contemporary of Euclid, practiced medicine in Alexandria in the third century B.C., and seems to have been the first Western scientist to dissect the human body. He made especially impressive contributions to many branches of anatomy and also developed influential views on many other aspects of medicine. Von Staden assembles the fragmentary evidence concerning one of the more important scientists of ancient Greece. Part 1 of the book presents the Greek and Latin texts accompanied by English translation and (...) interpretative commentary. Significant background information is given in the introductory essay preceding each chapter. Part 2 briefly sketches the major developments within the Herophilean school after Herophilus, and discusses the individual members within it. Anyone interested in the history of science, the history of medicine, or intellectual history will find this book a rich source of information about an unusual and important aspect of Greek culture. (shrink)

Der Verfasser beschreibt in lebendiger Weise das Werden seiner «philosophischen Existenz», wobei er besonders Ereignisse schildert, die ihm auf der Suche nach Sinn wichtig sind. So profiliert sich in immer wieder neuen Abwandlungen die Erfahrung, dass, wenn man sich einer Aufgabe zur Verfügung stellt und sich von Widerständen nicht bestimmen lässt, sondern «aus sich heraustritt», sich die Dinge fügen und zu einer ungeahnten positiven Wirkung führen können. Darin zeigt sich, dass das Seiende darauf angelegt ist, laufend aus sich herauszugehen, zu (...) «ek-sistieren», um in dieser Auseinandersetzung tiefer zu sich selbst zu kommen. Diese philosophische Autobiographie gliedert sich nach den vier Lebensetappen: Kindheit, Jugend, berufliche Aktivität, Seniorenalter. Den Band beschließt eine Skizze der Grundzüge der Philosophie des Autors, zu der die vorausgegangene Lebensdarstellung einen existentiellen Zugang ermöglicht; umgekehrt gewinnt so die Aussage des Lebens eine philosophische Fundierung. Das Buch leistet von einer neuen Seite her - einer philosophisch reflektierten Lebenserfahrung - einen aktuellen Beitrag zur geistigen Auseinandersetzung. Es vermittelt zugleich eine Ermutigung zum Wagnis menschlicher «Ek-sistenz». (shrink)