Bundel inleidende colleges op pre-kandidaatsniveau.

A novel Kabbalistic synthesis on the nature of consciousness.

This article argues in favour of voluntary active euthanasia in human beings on the grounds that we (society in general) perform euthanasia on valued companion animals when their suffering is considered great. I argue that suffering is a morally relevant criterion that should be considered in all cases (human and animal) of euthanasia. I further argue that human beings possess autonomy, a morally relevant difference to companion animals, that allows them to reason about their futures in a way that animals (...) cannot, which gives us more reason to grant euthanasia, if requested autonomously by terminally ill patients who are experiencing extreme suffering. I consider objections around the sanctity of human life and sufficient palliation. I argue that neither of these objections give sufficient reason to deny competent human beings euthanasia if autonomously requested. (shrink)

Building on the recent scholarship of Bonnie Kent, Christian Trottmann, and especially L.M. de Rijk, this volume gathers together studies by other specialists on Odonis, covering his ideas in economics, logic, metaphysics, ethics, natural ...

Social scientists increasingly use social media data to illuminate long-standing substantive questions in social science research. However, a key challenge of analyzing such data is their lower level of individual detail compared to highly detailed survey data. This limits the scope of substantive questions that can be addressed with these data. In this study, we provide a method to upgrade individual detail in terms of ethnicity in data gathered from social media via the use of register data. Our research aim (...) is twofold: first, we predict the most likely value of ethnicity, given one's first name, and second, we show how one can test hypotheses with the predicted values for ethnicity as an independent variable while simultaneously accounting for the uncertainty in these predictions. We apply our method to social network data collected from Facebook. We illustrate our approach and provide an example of hypothesis testing using our procedure, i.e., estimating the relation between predicted network ethnic homogeneity on Facebook and trust in institutions. In a comparison of our method with two other methods, we find that our method provides the most conservative tests of hypotheses. We discuss the promise of our approach and pinpoint future research directions. (shrink)

During the last thirty years both the social sciences and humanities in many countries have experienced a huge increase in student numbers, often directly related to national policies aimed at enlarging access to higher education for the majority of a generation. Although this evolution seems globally positive, it has also caused some specific problems within those disciplines, such as anthropology, which until recently led only to academic careers. In most European countries anthropological teaching has been predominantly research-oriented, that is rather (...) than ‘knowledge-oriented’ like disciplines taught in secondary education. In this paper, after having recalled some aspects of the teaching of anthropology since the 1950s, I would like to propose certain arguments for a discussion about the aims and means of teaching social sciences in general and anthropology in particular in the coming decades. Given the actual ‘dis-ease’ about this topic, this debate seems to becoming more and more inevitable. (shrink)

We consider some modal languages with a modal operator D whose semantics is based on the relation of inequality. Basic logical properties such as definability, expressive power and completeness are studied. Also, some connections with a number of other recent proposals to extend the standard modal language are pointed at.

This modern, advanced textbook reviews modal logic, a field which caught the attention of computer scientists in the late 1970's.

Although ethical guidelines for doing Internet research are available, most prominently those of the Association of Internet Researchers, ethical decision-making for research on publ...

In many logics dealing with information one needs to make statements not only about cognitive states, but also about transitions between them. In this paper we analyze a dynamic modal logic that has been designed with this purpose in mind. On top of an abstract information ordering on states it has instructions to move forward or backward along this ordering, to states where a certain assertion holds or fails, while it also allows combinations of such instructions by means of operations (...) from relation algebra. In addition, the logic has devices for expressing whether in a given state a certain instruction can be carried out, and whether that state can be arrived at by carrying out a certain instruction. This paper deals mainly with technical aspects of our dynamic modal logic. It gives an exact description of the expressive power of this language; it also contains results on decidability for the language with 'arbitrary' structures and for the special case with a restricted class of admissible structures. In addition, a complete axiomatization is given. The paper concludes with a remark about the modal algebras appropriate for our dynamic modal logic, and some questions for further work. The paper only contains some sketchy examples showing how the logic can be used to capture situations of dynamic interest, far more detailed applications are given in a companion to this paper (De Rijke [33]). (shrink)

For an arbitrary similarity type of Boolean Algebras with Operators we define a class of Sahlqvist identities. Sahlqvist identities have two important properties. First, a Sahlqvist identity is valid in a complex algebra if and only if the underlying relational atom structure satisfies a first-order condition which can be effectively read off from the syntactic form of the identity. Second, and as a consequence of the first property, Sahlqvist identities are canonical, that is, their validity is preserved under taking canonical (...) embedding algebras. Taken together, these properties imply that results about a Sahlqvist variety V van be obtained by reasoning in the elementary class of canonical structures of algebras in V. We give an example of this strategy in the variety of Cylindric Algebras: we show that an important identity called Henkin's equation is equivalent to a simpler identity that uses only one variable. We give a conceptually simple proof by showing that the firstorder correspondents of these two equations are equivalent over the class of cylindric atom structures. (shrink)

The debate on probabilistic measures of coherence has focused on evaluating sets of consistent propositions. In this paper we draw attention to the largely neglected question of whether such measures concur with intuitions on test cases involving inconsistent propositions and whether they satisfy general adequacy constraints on coherence and inconsistency. While it turns out that, for the vast majority of measures in their original shape, this question must be answered in the negative, we show that it is possible to adapt (...) many of them in order to improve their performance. (shrink)

We introduce a notion of bisimulation for graded modal logic. Using this notion, the model theory of graded modal logic can be developed in a uniform manner. We illustrate this by establishing the finite model property and proving invariance and definability results.

Recently there have been several attempts in formal epistemology to develop an adequate probabilistic measure of coherence. There is much to recommend probabilistic measures of coherence. They are quantitative and render formally precise a notion—coherence—notorious for its elusiveness. Further, some of them do very well, intuitively, on a variety of test cases. Siebel, however, argues that there can be no adequate probabilistic measure of coherence. Take some set of propositions A, some probabilistic measure of coherence, and a probability distribution such (...) that all the probabilities on which A’s degree of coherence depends (according to the measure in question) are defined. Then, the argument goes, the degree to which A is coherent depends solely on the details of the distribution in question and not at all on the explanatory relations, if any, standing between the propositions in A. This is problematic, the argument continues, because, first, explanation matters for coherence, and, second, explanation cannot be adequately captured solely in terms of probability. We argue that Siebel’s argument falls short. (shrink)

We study several modal languages in which some (sets of) generalized quantifiers can be represented; the main language we consider is suitable for defining any first order definable quantifier, but we also consider a sublanguage thereof, as well as a language for dealing with the modal counterparts of some higher order quantifiers. These languages are studied both from a modal logic perspective and from a quantifier perspective. Thus the issues addressed include normal forms, expressive power, completeness both of modal systems (...) and of systems in the quantifier tradition, complexity as well as syntactic characterizations of special semantic constraints. Throughout the paper several techniques current in the theory of generalized quantifiers are used to obtain results in modal logic, and conversely. (shrink)

A special interest in optics among various seventeenth-century painters living in the Dutch city of Delft has intrigued historians, including art historians, for a long time. Equally, the impressive career of the Delft microscopist Antoni van Leeuwenhoek has been studied by many historians of science. However, it has never been investigated who, at that time, had access to the mathematical and optical knowledge necessary for the impressive achievements of these Delft practitioners. We have tried to gain insight into Delft as (...) a ‘node’ of optical knowledge by following the careers of three minor local figures in early seventeenth-century Delft. We argue that through their work, products, discussions in the vernacular and exchange of skills, rather than via learned publications, these practitioners constituted a foundation on which the later scientific and artistic achievements of other Delft citizens were built. Our Delft case demonstrates that these practitioners were not simple and isolated craftsmen; rather they were crucial components in a network of scholars, savants, painters and rich virtuosi. Decades before Vermeer made his masterworks, or Van Leeuwenhoek started his famous microscopic investigations, the intellectual atmosphere and artisanal knowledge in this city centred on optical topics. (shrink)

Peirce algebras combine sets, relations and various operations linking the two in a unifying setting. This paper offers a modal perspective on Peirce algebras. Using modal logic as a characterization of the full Peirce algebras is given, as well as a finite axiomatization of their equational theory that uses so-called unorthodox derivation rules. In addition, the expressive power of Peirce algebras is analyzed through their connection with first-order logic and the fragment of first-order logic corresponding to Peirce algebras is described (...) in terms of bisimulations. (shrink)

Coherence is the property of propositions hanging or fitting together. Intuitively, adding a proposition to a set of propositions should be compatible with either increasing or decreasing the set’s degree of coherence. In this paper we show that probabilistic coherence measures based on relative overlap are in conflict with this intuitive verdict. More precisely, we prove that according to the naive overlap measure it is impossible to increase a set’s degree of coherence by adding propositions and that according to the (...) refined overlap measure no set’s degree of coherence exceeds the degree of coherence of its maximally coherent subset. We also show that this result carries over to all other subset-sensitive refinements of the naive overlap measure. As both results stand in sharp contrast to elementary coherence intuitions, we conclude that extant relative overlap measures of coherence are inadequate. (shrink)

Relative overlap measures of coherence have recently been shown to have two devastating properties: according to the plain relative overlap measure, the degree of coherence of any set of propositions cannot be increased by adding further propositions, and according to the refined relative overlap measure, no set can be more coherent than its most coherent two-element subset. This result has been taken to rule out relative overlap as a foundation for a probabilistic explication of coherence. The present paper shows that (...) this view is premature: we propose a relative overlap measure that does not fall victim to the two properties. The guiding idea is to employ a well-established recipe for the construction of coherence measures and to adapt it to the idea of relative overlap. We show that this new measure keeps up with, or even outperforms, former overlap measures in a set of desiderata for coherence measures and a collection of popular test cases. This result re-establishes relative overlap as a candidate for a proper formalization of coherence. (shrink)

One fundamental assumption often made in the literature on unawareness is that risk preferences are invariant to changes of awareness. We study how exposure to unawareness affects choices under risk. Participants in our experiment choose repeatedly between varying sure outcomes and a lottery in three phases. All treatments are exactly identical in phase 1 and phase 3, but differ in phase 2. There are five different treatments pertaining to the lottery faced in phase 2: The control treatment, the treatment with (...) awareness of unawareness of lottery outcomes but known number of outcomes, the treatment with awareness of unawareness of outcomes but with unknown number of outcomes, the treatment with unawareness of unawareness of some outcomes, and the treatment with an ambiguous lottery. We study both whether behavior differs in phase 3 across treatments and whether differences of subjects’ behavior between phases 1 and phase 3 differ across treatments. We observe no significant treatment effects. (shrink)

In [6] Albert Visser shows that ILP completely axiomatizes all schemata about provability and relative interpretability that are provable in finitely axiomatized theories. In this paper we introduce a system called ILP that completely axiomatizes the arithmetically valid principles of provability in and interpretability over such theories. To prove the arithmetical completeness of ILP we use a suitable kind of tail models; as a byproduct we obtain a somewhat modified proof of Visser's completeness result.

This study offers a re-interpretation of basic elements of Aristotle's semantics and metaphysics on the basis of a meticulous reconstruction of his semantics. By eliminating anachronistic conceptions commonly ascribed to him, many shortcomings or obscurities he is accused of will disappear.

People with cancer, who live better or longer than expected or who recover completely despite a poor medical prognosis, usually go through a profound change and self-development. This paper is an attempt to describe and understand the nature of this transformation by examining how initially unexamined conceptions of oneself, life, illness, etc., become manifest and get developed. One feature of this process is that people leave the present-day medical conception, which is based on the notion of victim of and battle (...) against illness, and discover that they have other resources for dealing with life and illness. It will be argued that at the centre of this transformation lies the discovery and development of the will, which is closely associated with the willingness to examine one's conceptions of oneself, health, illness and life. (shrink)

Le but de cet article est une critique de la philosophie politique de M. Eric Weil. Par opposition à M. Weil, l'auteur définit la „politique" ici comme l'art du réalisable, à préciser comme : l'art d'arriver à court terme à une organisation de la société qu'on estime meilleure, et cela en employant tous les moyens permis. L'homme politique n'est pas, ainsi que l'affirme M. Weil, un „saint de Vtmiversel”, qui, en ce qui concerne l'emploi de la violence, se trouve au-dessus (...) de la loi. Ce „politicien-éducateur” est en vérité l'appui des régimes totalitaires et est d'ailleurs inconcevable en dehors de ceux-ci. En outre la théorie de M. Weil contient un certain nombre de contradictions internes et, si on la mesure à la pratique, elle se trouve être déficiente à beaucoup d'égards. Contre la conception platonicienne de M. Weil l'auteur défend la thèse que la politique n'est pas une infraction, regrettable mais inévitable, à „la morale”. C'est la tâche de l'homme politique de supprimer toutes les absurdités, inconséquences et injustices qui entachent les structures de la société. Ce qui, concrètement, est absurde, inconséquent ou injuste n'est pas déterminé par „la morale”, mais par la conscience du droit et par le sentiment moral d'une époque donnée. Les „certitudes” d'où part l'homme politique ne sont pas des Idées platoniciennes, mais des hypothèses de travail, qui dérivent leur contenu non pas de la contemplation des Idées, mais d'une notion de ce qui est juste et désirable, notion qui est déterminée par les conditions matérielles et spirituelles et qui se trouve dans un changement continuel. (shrink)

This edition of Giraldus Odonis' Logica for the first time gives access to an important and original treatise, which has unduly been neglected since the author's death. It is also important in that it gives evidence of interesting achievements in the field of logic outside the anti-metaphysical circle surrounding Ockham.

This volume not only provides the first critical edition with an English translation of the famous correspondence of Nicholas of Autrecourt , but also an assessment of his views and the views of those to whom the letters were addressed.

The first critical edition of the _Syncategoreumata_ by the thirteenth-century philosopher Peter of Spain, accompanied by a facing-page English translation to make its contents accessible to modern readers. The introduction gives an account of all the manuscripts used for the edition. Extensive indexes have been added to facilitate the reader's orientation in the book.

In this paper, I first present an overview of Asay’s _A Theory of Truthmaking_, highlighting what I take to be some of its most attractive features, especially his re-invigoration of the ontological understanding of truthmaking and his defence of ontology-first truthmaking over explanation-first truthmaking. Then, I articulate what I take to be a puzzling potential inconsistency: (a) he appeals to considerations to do with aboutness in criticising how well ontological views account for truth while (b) ruling out aboutness from the (...) right account of truthmaking. He argues, instead, that necessitation is both necessary and sufficient for truthmaking (§3.3). I suggest that adding aboutness to one’s account in the right way is not just compatible with but important for ontology-first truthmaking. I do all this to invite Asay to clarify his position on these matters. Overall, Asay’s worldview displays the fruitfulness of an ontologically serious approach to metaphysics that puts truthmaking centre-stage. (shrink)

Truthmaker theory has been used to argue for substantial conclusions about the categorial structure of the world, in particular that states of affairs are needed to play the role of truthmakers. In this paper, I argue that closely considering the role of aboutness in truthmaking, that is considering what truthbearers are about, yields the result that there is no good truthmaker-based reason to think that truthmakers must be states of affairs understood as existing entities, whether complex or simple. First, I (...) introduce an aboutness-based account of truthmaking as a metaphysically modest alternative to the orthodox necessitarian account of truthmaking. Second, I discuss the distinction between states and events that has been made on the basis of linguistic evidence regarding aspectual markers and nominalisation. I argue that the modest approach to truthmaking allows us to accept that there is a real distinction between states and events without requiring that the distinction is ontologically substantial. Specifically, what we are talking about with state-truthbearers really differs from what we are talking about with event-truthbearers, but this difference need not be understood as a difference in kinds of entities. Because of its overall modesty, this is a theoretically virtuous result. (shrink)

The debate on probabilistic measures of coherence flourishes for about 15 years now. Initiated by papers that have been published around the turn of the millennium, many different proposals have since then been put forward. This contribution is partly devoted to a reassessment of extant coherence measures. Focusing on a small number of reasonable adequacy constraints I show that (i) there can be no coherence measure that satisfies all constraints, and that (ii) subsets of these adequacy constraints motivate two different (...) classes of coherence measures. These classes do not coincide with the common distinction between coherence as mutual support and coherence as relative set-theoretic overlap. Finally, I put forward arguments to the effect that for each such class of coherence measures there is an outstanding measure that outperforms all other extant proposals. One of these measures has recently been put forward in the literature, while the other one is based on a novel probabilistic measure of confirmation. (shrink)

A central problem for any truthmaker theory is the problem of negative truths. In this paper, I develop a novel, piecemeal strategy for solving this problem. The strategy puts central focus on a truth-relevant notion of aboutness within a metaphysically modest version of truthmaker theory and uses key conceptual tools gained by taking a deeper look at the best attempts to solve the problem of intentionality. I begin this task by critically discussing past proposed solutions to P-NEG in light of (...) Russell’s debate with Demos. This reveals a central difficulty with addressing the problem, specifically that one cannot be committed to incompatibility facts in one’s account of negation and of the truth of negative truths. I then present an aboutness-based version of truthmaker theory. Utilising what I call the strict and full account of aboutness, I extract aboutness-based theories of truth and falsity. I use this machinery to present a promising new strategy for solving P-NEG which does not have the problems of alternative approaches. Finally, I present and respond to some potential objections. (shrink)