Free logic - i.e., logic free of existential presuppositions in general and with respect to singular terms in particular- began to come into its own as a field of research in the 1950s. As is the case with so many developments in Western philosophy, its roots can be traced back to ancient Greek philo sophy. It is only during the last fifty years, however, that it has become well established as a branch of modern logic. The name of Karel Lambert (...) is most closely connected with this development: he gave it its name and its profile as a well defined field of research. After a development of fifty years, it is time to look back and take stock while at the same time scanning for new perspectives. This is the purpose of the papers collected in this volume. The first paper is written by Karel Lambert himself who also comments on all the papers of the other authors. In an introductory essay we give a survey of the present status of and new directions in free logic. (shrink)

The question ''Was 'existence' ever a predicate?" in a way already suggests its own answer, that this is really the wrong question to ask, because 'existence' has always been a predicate. Even those, such as Kant, who supposedly opposed this view, in fact held it. They merely denied that 'existence' is a "normal" first-order predicate. Not only Kant, but also Bolzano, Frege and Russell claimed that it is a second-order predicate. There is substantive disagreement between Kant and Bolzano on the (...) one hand and Frege and Russell on the other over two issues: the former claim that this second-order predicate apphes to no concept analytically and that it can be properly ascribed to a singular concept, whereas the latter deny both of these claims. (shrink)

Bernard Bolzano's most fruitful invention was his method of variation. He used it in defining such fundamental logical concepts as logical consequence, analyticity and probability. The following three puzzles concerning this method of variation seem particularly worth considering, (i) How can we define the range of variation of an idea or the categorial conformity of two ideas without already using the concept of variation? This question was raised by Mark Siebel in his M. A. thesis, (ii) Why must we define (...) analyticity by means of (simultaneous or successive) variation of several ideas rather than by means of replacing a single idea? This problem is suggested by an example due to W.V.O. Quine, John R. Myhill and Benson Mates, (iii) Must every 'there is ...' sentence be synthetic for Bolzano, as his pupil Franz Příhonský claims in his booklet Neuer Anti-Kant, or can a 'there is...' sentence be logically analytic? (shrink)

Investigating the genesis and justification of norms in a theoretical way requires a clear-cut distinction between normative and descriptive discourse. From a philosophical perspective, the descriptive-normative dichotomy can itself be understood either in a descriptive (or ‘reportive’) or in an normative (or ‘stipulative’) way. In the first case such a dichotomy is understood as the factual border between descriptive and normative discourse in a given language; exploring this border is a hermeneutic enterprise. In the other case it is understood as (...) a boundary between descriptive and normative discourse to be implanted in a language which is developed in order to fit certain purposes, in particular theoretical purposes; this implanting procedure is a matter of regimentation. In this paper I will deal shortly with the first question of hermeneutics and then in more detail with the second question of regimentation. In the final part of the paper I will distinguish different types of naturalistic fallacies resulting from disregarding descriptive-normative dichotomies. (shrink)

The first part of this paper summarizes what I take to be the most important doctrines of Brentano's philosophy. The second part investigates the possible meanings of the term 'Austrian philosophy'. The third part attempts to say something about Brentano's place in Austrian philosophy -- whatever that may be --, while the fourth part focuses on a problem in which I am especially interested. The paper closes with a proposal for what the expression 'Austrian philosophy' could mean.

This discussion note deals with Jurriaan de Haan's paper The Definition of Moral Dilemmas: A Logical Problem (Ethical Theory and Moral Practice 4(3), 2001, pp. 267–284). In the first, critical part I will point out a confusion in the logical analysis of the paper in question. In the second, constructive part I will indicate how the analysis of moral dilemmas should proceed within the framework of a possible world semantics.

The first part of this paper summarizes what I take to be the most important doctrines of Brentano's philosophy. The second part investigates the possible meanings of the term 'Austrian philosophy'. The third part attempts to say something about Brentano's place in Austrian philosophy — whatever that may be --, while the fourth part focuses on a problem in which I am especially interested. The paper closes with a proposal for what the expression 'Austrian philosophy' could mean.

Bernard Bolzano's most fruitful invention was his method of variation. He used it in defining such fundamental logical concepts as logical consequence, analyticity and probability. The following three puzzles concerning this method of variation seem particularly worth considering, How can we define the range of variation of an idea or the categorial conformity of two ideas without already using the concept of variation? This question was raised by Mark Siebel in his M. A. thesis, Why must we define analyticity by (...) means of variation of several ideas rather than by means of replacing a single idea? This problem is suggested by an example due to W.V.O. Quine, John R. Myhill and Benson Mates, Must every 'there is...' sentence be synthetic for Bolzano, as his pupil Franz Příhonský claims in his booklet Neuer Anti-Kant, or can a 'there is...' sentence be logically analytic? (shrink)

D’après Bolzano, une proposition est logiquement analytique si et seulement si elle est soit logiquement valide, soit logiquement non valide. Bolzano dit aussi parfois qu’une proposition est logiquement valide si et seulement si elle est et reste vraie sous toute variation simultanée et uniforme de ses parties non logiques. C’est essentiellement la même définition que donne Quine dans son article « Carnap and Logical Truth » où il attribue à ce dernier l’idée qu’un énoncé logiquement vrai est un énoncé au (...) sein duquel seuls les termes logiques sont essentiels. Mais qu’en est-il des propositions et des énoncés vrais qui sont composés exclusivement de parties logiques ? Selon la définition précédente, elles s’avèreraient toutes logiquement valides ou logiquement vraies. Une proposition telle que « Il y a quelque chose » n’est toutefois manifestement pas logiquement valide selon Bolzano. La définition courante de la validité logique doit être modifiée de manière à répondre aux intuitions bolzaniennes. Dans cet article, je propose une telle modification.A proposition is logically analytic according to Bolzano if and only if it is either logically valid or logically non-valid. And a proposition is sometimes said to be logically valid according to Bolzano if and only if it is true and remains true under all simultaneous and uniform variations of all of its non-logical parts. Basically the same definition is provided by Quine in his paper “Carnap and Logical Truth” where he attributes to Carnap the view that a logically true sentence is a true sentence which involves only logical words essentially. But, what about true propositions and sentences which are composed exclusively of logical parts ? Due to the definition mentioned above, all of them will trivially turn out as logically valid or logically true. A proposition like “There is something”, however, is clearly not logically valid according to Bolzano. The common definition of logical validity must be modified in order to match Bolzano’s intuitions. In this paper, such a modification is presented. (shrink)

Die Rede von Existenz als Begriff zweiter Stufe ist – zumindest in dieser undif- ferenzierten Kurzform – eine überholte Legende, an deren Bildung neben Kant und Bolzano auch Frege nicht unbeteiligt war; obwohl er sie eigentlich mit sei- ner Begriffsschrift schon überwunden hatte, hat er sie weiter am Leben erhalten.

During the last two decades, applied ethics has not only developed into one of the most important philosophical disciplines but has also differentiated into so many subdisciplines that it is becoming increasingly difficult to survey it. A much-needed overview is provided by the eighteen contributions to this volume, in which internationally renowned experts deal with central questions of environmental ethics, bioethics and medical ethics, professional and business ethics, social, political, and legal ethics as well as with the aims and foundations (...) of applied ethics in general. Thanks to a philosophical introduction and selected bibliographical references added to each chapter, the book is very well suited as a basis for courses in applied ethics. It is directed not only to philosophers and to ethicists from other disciplines but to scientists in general and to all people who are interested in the rational discussion of moral principles and their application to concrete problems in the sciences and in everyday life. (shrink)

The question ''Was 'existence' ever a predicate?" in a way already suggests its own answer, that this is really the wrong question to ask, because 'existence' has always been a predicate. Even those, such as Kant, who supposedly opposed this view, in fact held it. They merely denied that 'existence' is a "normal" first-order predicate. Not only Kant, but also Bolzano, Frege and Russell claimed that it is a second-order predicate. There is substantive disagreement between Kant and Bolzano on the (...) one hand and Frege and Russell on the other over two issues: the former claim that this second-order predicate apphes to no concept analytically and that it can be properly ascribed to a singular concept, whereas the latter deny both of these claims. (shrink)

Nicht nur in der Alltagssprache, sondern auch in der Sprache des Wissenschaftlers spielt die Verwendung von Superlativen eine wichtige Rolle. Für gewöhnlich geht man dabei vom jeweiligen Komparativ aus und führt hernach den dazugehörigen Superlativ ein. Für die Definition des Superlativs mit Hilfe des entsprechenden Komparativs kommen jedoch mehrere Möglichkeiten in Betracht, welche genau auseinandergehalten werden müssen; die Unterschiede, die sich dabei ergeben, sollen hier im einzelnen herausgearbeitet werden.