Aan de hand van recente ontdekkingen op het gebied van neurowetenschappen, biologische evolutie, paleontologie, evolutionaire psychologie en evolutionaire dynamicamodellen, leggen Dirk Van Duppen en Johan Hoebeke uit hoe pro-sociale gedragingen en altruïsme het succes van de ‘homo sapiens’ evolutionair hebben bepaald. Vermits de mens als meest kwetsbaar en meest prematuur dier op de wereld is gekomen, was zijn enige manier om te overleven een biologisch-culturele co-evolutie waarbij zijn intelligente vermogens zich enkel konden ontwikkelen door zijn ingeslepen drang om (...) zich sociaal te gedragen. Dit wetenschappelijk gegrond beeld van de ‘homo sapiens’ staat volledig haaks op dit van de neoliberale ‘homo economicus’ die enkel op individuele winstmaximalisatie gericht is en op de competitiedrang, die als enige drijfkracht voor de vooruitgang wordt beschouwd. De discrepantie tussen de biologisch-culturele fundamenten van onze soort en de actuele overheersende ideologie waaraan wij continu onderworpen worden, zou het stijgend ongenoegen en het ‘mal vivre’ in onze maatschappijen kunnen verklaren. Zoals José Saramago het uitte: ‘Als de omstandigheden zo bepalend zijn voor de mens, laat ons dan die omstandigheden meer menselijk maken.’. (shrink)

For more than 20 years now, the phenomenological approach to schizophrenia has developed a strong and influential hypothesis on the basic alterations of this disorder. Schizophrenia, it is claimed, is a disorder of subjectivity, and more specifically, a disorder of the minimal self. This ‘minimal self’ aims to describe the most basic or core self, which is considered to be foundational for every other kind of self. It is a form of minimal self-awareness that precedes every explicit or reflective self-awareness. (...) Based on this model, a semistructured interview has... (shrink)

Over the past years, the intersubjective dimension of psychotic disorders, including schizophrenia, has gained increasing phenomenological attention. Psychopathologists and philosophers have developed ideas on how the social aspects of psychotic symptoms and experiences could be understood, in particular in their relation to the ipseity disturbance model, namely the idea that schizophrenia is essentially a disorder of the minimal self. Although the exact characteristics of the ipseity disorder hypothesis can differ from author to author, emphasizing certain phenomenological aspects like temporality or (...) embodiment... (shrink)

Contemporary perspectives on delusions offer valuable neuropsychiatric, psychoanalytic, and philosophical explanations of the formation and persistence of delusional phenomena. However, two problems arise. Firstly, these different perspectives offer us an explanation “from the outside”. They pay little attention to the actual personal experiences, and implicitly assume their incomprehensibility. This implicates a questionable validity. Secondly, these perspectives fail to account for two complex phenomena that are inherent to certain delusions, namely double book-keeping and the primary delusional experience. The purpose of this (...) article is to address both problems, by offering an understanding “from the inside”. Our phenomenological approach is a form of “radical empathy”, and crosses the Jaspersian limits of understanding. It compares delusional experiences with variations of reality experience in everyday life, and makes use of the structure of imagination. Six factors influencing the experience of reality are discussed and illustrated by clinical and non-clinical examples. These factors are: continuity, materiality and resistance, multiplicity of sensations and perceptions, intensity, the sense of authorship, and the complex role of intersubjectivity. I suggest that experiences of hypo- and hyperreality are not restricted to pathology, but have their place in everyday life as well. Delusional phenomena can be better understood by investigating the interplay of these six factors. With this framework, the two complex phenomena consequently prove to be better understandable to us. Our approach remains within the phenomenal experience and might thereby contribute to the validity of psychopathology. (shrink)

Phenomenological psychopathology is a research field that aims to investigate and describe the subjective experience of mental disorders. By suspending the assumptions about etiology and causality as much as possible, and by focusing on the subjective experiences of the patient, it is supposed to offer a profound understanding of the patient’s suffering, and of the disorder in general. Clarity in the description of these experiences is, therefore, a necessity. Traditionally, phenomenological psychopathology was studied mostly by European, and particularly by German (...) and French psychiatrists, such as Karl Jaspers, Wolfgang Blankenburg, and Eugène Minkowski. Today, psychopathologists like Josef Parnas, Giovanni... (shrink)

BACKGROUND: Delusions in schizophrenia are commonly approached as empirical false beliefs about everyday reality. Phenomenological accounts, by contrast, have suggested that delusions are more adequately understood as pertaining to a different kind of reality experience. How this alteration of reality experience should be characterised, which dimensions of experiential life are involved, and whether delusional reality might differ from standard reality in various ways is unclear and little is known about how patients with delusions value and relate to these experiential alterations. (...) This study aimed to investigate the nature of delusional reality experience, and its subjective apprehension, in individuals with lived experience of delusions and a schizophrenia-spectrum diagnosis. METHODS: In this qualitative phenomenological study, we recruited individuals with lived experience of delusions and a schizophrenia-spectrum diagnosis from two psychiatric-hospital services in Belgium using homogenous sampling. Criteria for participation were having undergone at least one psychotic episode with occurring delusional symptoms, present at least 1 year before participation, on the basis of clinical notes assessed by the attending psychiatrist; a schizophrenia-spectrum diagnosis, ascertained through clinical interview by the attending psychiatrist upon admission; being aged between 18 years and 65 years; and having the capacity to give informed consent. Exclusion criteria included worries concerning capacity to consent and risk of distress caused by participation. We did phenomenologically driven semi-structured interviews with the participants to explore the nature of delusional reality experience and their subjective valuation of these experiences. We used interpretative phenomenological analysis, a qualitative method tailored to the in-depth exploration of participants’ first-person perspective, to analyse their accounts. FINDINGS: Between March 2, 2020, and Sept 30, 2020, 18 adults participated in the interview study. The findings suggest that delusions are often embedded in wide-ranging alterations of basic reality experience, involving quasi-ineffable atmospheric and ontological qualities that undermine participants’ sense of the world as unambiguously real, fully present, and shared with others. We also found that delusional reality experience can differ from standard reality in various ways, across multiple dimensions, and that participants are often implicitly or explicitly aware of the distinction between delusional and standard reality. Delusional experience can have an enduring value and meaning that is not fully captured by a strictly medical perspective. INTERPRETATION: Increased awareness and recognition of the distinctive nature of delusional reality experience, in both clinical and research settings, can improve diagnostic accuracy, explanatory models, and therapeutic support for individuals with delusions whose lived realities are not always evident from an everyday perspective. FUNDING: FWO Flanders. TRANSLATION: For the Dutch translation of the abstract see Supplementary Materials section. (shrink)

Mit Schmitt ragte der Träger eines Traditionsbestandes politischen Denkens in die Zeit der frühen Bundesrepublik hinein, von dem sich abzugrenzen in den 50er Jahren Übereinkunft zu herrschen schien. Aber schon die Art, wie er seine eigene kompromittierende Vergangenheit als intellektueller Kollaborateur des,Dritten Reiches' verarbeitete, führte Schmitt erneut Gesprächspartner zu. Diese Freundeskreise ergänzten sich nach und nach durch immer weitere Interessenten zu einem netzwerkartigen Gesprächszusammenhang. Dessen Heterogenität und die Vielfalt der Rezeptionsweisen seiner Theoreme stand zu dem Bild, welches sich mit dem (...) Namen Carl Schmitt in der offiziellen politischen Kultur verknüpfte, in einer irritierenden Spannung. These der Arbeit ist, daß sich aus dieser Spannung auf wichtige Merkmale der Intellektuellengeschichte der frühen Bundesrepublik insgesamt rückschließen läßt. (shrink)

Drawing on letters, orations and disputations, this book argues that during the seventeenth century, the Amsterdam Athenaeum, despite the revolutionary debates of the time, and despite the intellectual liberalism characteristic of Amsterdam, remained traditional in its teaching.

This chapter contains sections titled: Logic: The Proof Interpretation Analysis: Choice Sequences Further Semantics.

Lexical diversity, the amount of lexical variation shown by a particular concept, varies between concepts. For the conceptdrunk, for instance, nearly 3000 English expressions exist, includingblitzed, intoxicated, andhammered. For the conceptsober, however, a significantly smaller number of lexical items is available, likesoberorabstinent. While earlier variation studies have revealed that meaning-related concept characteristics correlate with the amount of lexical variation, these studies were limited in scope, being restricted to one semantic field and to one dialect area, that of the Limburgish dialects (...) of Dutch. In this paper, we investigate whether the impact of concept characteristics, viz. vagueness, lack of salience and proneness to affect, is manifest in a similar way in other dialects and other semantic fields. In particular, by extending the scope of the earlier studies to other carefully selected semantic fields, we investigate the generalizability of the impact of concept characteristics to the lexicon as a whole. The quantitative approach that we employ to measure concept characteristics and lexical diversity methodologically advances the study of linguistic variation. Theoretically, this paper contributes to the further development of Cognitive Sociolinguistics by showcasing how meaning can be a source of lexical diversity. (shrink)

Volume 1 of this biography of L. E. J. Brouwer was published in 1999.1 The volume under review here covers the period from the early nineteen twenties until Brouwer's death in 1966. It also includes a short epilogue that discusses the disposition of Brouwer's estate after his death, his influence on others, the paths of some of his students and colleagues, and other matters. Van Dalen notes in the Preface that in preparing this volume he consulted some historical studies that (...) appeared after the first volume was published. He also used new material from various archives. The biography contains interesting quotations from unpublished materials in the Brouwer Archive and from correspondence. The bibliographical references to Brouwer's publications, it should be noted, are somewhat different in this volume. This volume, like the first, contains some nice photographs and reproductions. I noted that there were many typographical errors in the earlier book but Volume 2 is relatively free of them.As is the case in Volume 1, the discussion of Brouwer's mathematical and philosophical work is woven into the narrative of Brouwer's life and times. The story in this volume starts with Brouwer's first contacts with Paul Alexandrov and Paul Urysohn in 1923. The interaction began when Urysohn announced that he had found a mistake in Brouwer's definition of dimension in Brouwer's 1913 paper on natural dimension. Was it just a slip of the pen, as Brouwer always maintained, or something more substantial? Urysohn and Alexandrov ultimately came to agree with Brouwer on the matter, and Urysohn was prepared to grant Brouwer priority for the definition of dimension. There were, however, ups and downs along the way. Karl Menger, through his own work in topology and dimension theory, soon got into the picture, and Brouwer and Menger were to …. (shrink)

Via a historical reconstruction, this paper primarily demonstrates how the societal debate on genetically modified organisms (GMOs) gradually extended in terms of actors involved and concerns reflected. It is argued that the implementation of recombinant DNA technology out of the laboratory and into civil society entailed a “complex of concerns.” In this complex, distinctions between environmental, agricultural, socio-economic, and ethical issues proved to be blurred. This fueled the confusion between the wider debate on genetic modification and the risk assessment of (...) transgenic crops in the European Union. In this paper, the lasting skeptical and/or ambivalent attitude of Europeans towards agro-food biotechnology is interpreted as signaling an ongoing social request – and even a quest – for an evaluation of biotechnology with Sense and Sensibility. In this (re)quest, a broader-than-scientific dimension is sought for that allows addressing the GMO debate in a more “sensible” way, whilst making “sense” of the different stances taken in it. Here, the restyling of the European regulatory frame on transgenic agro-food products and of science communication models are discussed and taken to be indicative of the (re)quest to move from a merely scientific evaluation and risk-based policy towards a socially more robust evaluation that takes the “non-scientific” concerns at stake in the GMO debate seriously. (shrink)

Dirk van Dalen’s biography studies the fascinating life of the famous Dutch mathematician and philosopher Luitzen Egbertus Jan Brouwer. Brouwer belonged to a special class of genius; complex and often controversial and gifted with a deep intuition, he had an unparalleled access to the secrets and intricacies of mathematics. Most mathematicians remember L.E.J. Brouwer from his scientific breakthroughs in the young subject of topology and for the famous Brouwer fixed point theorem. Brouwer’s main interest, however, was in the foundation (...) of mathematics which led him to introduce, and then consolidate, constructive methods under the name ‘intuitionism’. This made him one of the main protagonists in the ‘foundation crisis’ of mathematics. As a confirmed internationalist, he also got entangled in the interbellum struggle for the ending of the boycott of German and Austrian scientists. This time during the twentieth century was turbulent; nationalist resentment and friction between formalism and intuitionism led to the Mathematische Annalen conflict. It was here that Brouwer played a pivotal role. The present biography is an updated revision of the earlier two volume biography in one single book. It appeals to mathematicians and anybody interested in the history of mathematics in the first half of the twentieth century. (shrink)

Servant leadership is increasingly gaining interest inside and outside academia. This article builds and extends current theorizing by describing the process that introduces compassionate love as a practical translation for the need to serve, which was positioned by Greenleaf as the core of servant leadership. This article takes a virtues perspective and shows how servant leadership may encourage a more meaningful and optimal human functioning with a strong sense of community to current-day organizations. In essence, we propose that a leader’s (...) propensity for compassionate love will encourage a virtuous attitude in terms of humility, gratitude, forgiveness and altruism. This virtuous attitude will give rise to servant leadership behavior in terms of empowerment, authenticity, stewardship and providing direction. (shrink)

Brouwer and Weyl recognized that the intuitive continuum requires a mathematical analysis of a kind that set theory is not able to provide. As an alternative, Brouwer introduced choice sequences. We first describe the features of the intuitive continuum that prompted this development, focusing in particular on the flow of internal time as described in Husserl's phenomenology. Then we look at choice sequences and their logic. Finally, we investigate the differences between Brouwer and Weyl, and argue that Weyl's conception of (...) choice sequences is defective on several counts. (shrink)

Dedicated to Dana Scott on his sixtieth birthday.It is common knowledge that for a short while Hermann Weyl joined Brouwer in his pursuit of a revision of mathematics according to intuitionistic principles. There is, however, little in the literature that sheds light on Weyl's role and in particular on Brouwer's reaction to Weyl's allegiance to the cause of intuitionism. This short episode certainly raises a number of questions: what made Weyl give up his own program, spelled out in “Das Kontinuum”, (...) how did Weyl come to be so well-informed about Brouwer's new intuitionism, in what respect did Weyl's intuitionism differ from Brouwer's intuitionism, what did Brouwer think of Weyl's views,…? To some of these questions at least partial answers can be put forward on the basis of some of the available correspondence and notes. The present paper will concentrate mostly on the historical issues of the intuitionistic episode in Weyl's career.Weyl entered the foundational controversy with a bang in 1920 with his sensational paper “On the new foundational crisis in mathematics”. He had already made a name for himself in the foundations of mathematics in 1918 with his monograph “The Continuum” [18]; this contained in addition to a technical logical-mathematical construction of the continuum, a fairly extensive discussion of the shortcomings of the traditional construction of the continuum on the basis of arbitrary—and hence also impredicative—Dedekind cuts. (shrink)

On October 4, 1937, Zermelo composed a small note entitled “Der Relativismus in der Mengenlehre und der sogenannte Skolemsche Satz” in which he gives a refutation of “Skolem's paradox”, i.e., the fact that Zermelo-Fraenkel set theory—guaranteeing the existence of uncountably many sets—has a countable model. Compared with what he wished to disprove, the argument fails. However, at a second glance, it strongly documents his view of mathematics as based on a world of objects that could only be grasped adequately by (...) infinitary means. So the refutation might serve as a final clue to his epistemological credo.Whereas the Skolem paradox was to raise a lot of concern in the twenties and the early thirties, it seemed to have been settled by the time Zermelo wrote his paper, namely in favour of Skolem's approach, thus also accepting the noncategoricity and incompleteness of the first-order axiom systems. So the paper might be considered a late-comer in a community of logicians and set theorists who mainly followed finitary conceptions, in particular emphasizing the role of first-order logic. However, Zermelo never shared this viewpoint: In his first letter to Gödel of September 21, 1931, he had written that the Skolem paradox rested on the erroneous assumption that every mathematically definable notion should be expressible by a finite combination of signs, whereas a reasonable metamathematics would only be possible after this “finitistic prejudice” would have been overcome, “a task I have made my particular duty”. (shrink)

The original Brouwerian counter examples were algorithmic in nature; after the introduction of choice sequences, Brouwer devised a version which did not depend on algorithms. This is the origin of the creating subject technique. The method allowed stronger refutations of classical principles. Here it is used to show that negative dense subsets of the continuum are indecomposable.

There are two principles that lend Brouwer's mathematics the extra power beyond arithmetic. Both are presented in Brouwer's writings with little or no argument. One, the principle of bar induction, will not concern us here. The other, the continuity principle for numbers, occurs for the first time in print in [4]. It is formulated and immediately applied to show that the set of numerical choice sequences is not enumerable. In fact, the idea of the continuity property can be dated fairly (...) precisely, it is to be found in the margin of Brouwer's notes for his course on Pointset Theory of 1915/16. The course was repeated in 1916/17 and he must have inserted his first formulation of the continuity principle in the fall of 1916 as new material right at the beginning of the course.In modern language, the principle readswhere α and β range over choice sequences of natural numbers, m and x over natural numbers, and stands for ⟨α, α, …, α⟩, the initial segment of α of length m.An immediate consequence of WC-N is that all full functions are continuous, and, as a corollary, that the continuum is unsplittable [28]. Note that WC-N is incompatible with Church's thesis, [22], section 4.6.After Brouwer asserted WC-N, Troelstra was the first to ask in print for a conceptual motivation, but he remained an exception; most authors followed Brouwer by simply asserting it, cf. [18].Let us note first that in one particular case the principle is obvious indeed, namely in the case of the lawless sequences. The notion of lawless sequence surfaced fairly late in the history of intuitionism. Kreisel introduced it in [17] for metamathematical purposes. There is a letter from Brouwer to Heyting in which the phenomenon also occurs [7]. This is an important and interesting fact since it is the only time that Brouwer made use of a possibility expressly stipulated in, e.g., [5], see below. (shrink)

Irrespective of the short academic history of Christian spirituality, a vast number of academic and popular publications ensued and is still dynamically growing. Many definitions have been proposed to define (Christian) spirituality. Spirituality is also no longer connected only to religion, although in this research the focus will fall on Christian spirituality. This research intends to partake in the continuing academic dialogue to define Christian spirituality. Christian spirituality is interpreted from the perspective of the divine-human conversation. This research consists of (...) three sections. In the first section, a working definition of Christian spirituality is formulated. In the second section, various aspects that constitute spiritualities are distinguished and discussed. In the last section, the constituents of Christian spirituality are pointed out and are reviewed from a conversational perspective. The focus will be on ‘the experience of the divine’ when living a life that resonates with the Christian life. (shrink)

There are basically two ways to view intuitionistic logic: as a philosophical‐foundational issue in mathematics; or as a technical discipline within mathematical logic. Considering first the philosophical aspects, for they will provide the motivation for the subject, this chapter follows L. E. J. Brouwer, the founding father of intuitionism. Although Brouwer himself contributed little to intuitionistic logic as seen from textbooks and papers, he did point the way for his successors.

The present volume is intended as an all-round introduction to constructivism. Here constructivism is to be understood in the wide sense, and covers in particular Brouwer's intuitionism, Bishop's constructivism and A.A. Markov's constructive recursive mathematics. The ending "-ism" has ideological overtones: "constructive mathematics is the (only) right mathematics"; we hasten, however, to declare that we do not subscribe to this ideology, and that we do not intend to present our material on such a basis.

In the present paper the story is told of the brief and far from tranquil encounter of L.E.J. Brouwer and A. Fraenkel. The relationship which started in perfect harmony, ended in irritation and reproaches.The mutual appreciation at the outset is beyond question. All the more deplorable is the sudden outbreak of an emotional disagreement in 1927. Looking at the Brouwer–Fraenkel episode, one should keep in mind that at that time the so-called Grundlagenstreit was in full swing. An emotional man like (...) Brouwer, who easily suffered under stress, was already on edgewhen Fraenkel's book Zehn Vorlesungen Über die Grundlegung der Mengenlehre, [Fraenkel 1927] was about to appear.With the Grundlagenstreit reaching a level of personal abuse unusual in the quiet circles of pure mathematics, Brouwer was rather sensitive, where the expositions of his ideas were concerned. So when he thought that he detected instances of misconception and misrepresentation in the case of his intuitionism, he felt slighted. We will mainly look at Brouwer's reactions. since the Fraenkel letters have not been preserved.The late Mrs. Fraenkel kindly put the Brouwer letters that were in her possession at my disposal. I am grateful to the Fraenkel family for the permission to use the material.I am indebted to Andreas Blass for his valuable suggestions and corrections.Abraham Fraenkel was one of the first non-partisan mathematicians, if not the first, who developed a genuine interest in intuitionism. (shrink)