Ongoing developments, such as digitalization, increased the interference of the work and nonwork life domains, urging many to continuously manage engagement in respective domains. The COVID-19 pandemic and subsequent home-office regulations further boosted the need for employees to find a good work-nonwork balance, thereby optimizing their health and well-being. Consequently, proactive individual-level crafting strategies for balancing work with other relevant life domains were becoming increasingly important. However, these strategies received insufficient attention in previous research despite their potential relevance for satisfying (...) psychological needs, such as psychological detachment. We addressed this research gap by introducing a new scale measuring crafting for a work-nonwork balance and examining its relevance in job-and life satisfaction, work engagement, subjective vitality, family role and job performance, boundary management and self-rated work-nonwork balance. The Work-Nonwork Balance Crafting Scale was validated in five countries, encompassing data from a heterogeneous sample of more than 4,200 employees. In study 1, exploratory factor analysis revealed a two-factorial scale structure. Confirmatory factor analysis, test for measurement invariance, and convergent validity were provided in study 2. Replication of confirmatory factor analysis, incremental and criterion validity of the Work-Nonwork Balance Crafting Scale for job and life satisfaction were assessed in study 3. Study 4 displayed criterion validity, test–retest reliability, testing measurement invariance, and applicability of the scale across work cultures. Finally, study 5 delivered evidence for the Work-Nonwork Balance Crafting Scale in predicting work-nonwork balance. The novel Work-Nonwork Balance Crafting Scale captured crafting for the challenging balance between work and nonwork and performed well across several different working cultures in increasingly digitalized societies. Both researchers and practitioners may use this tool to assess crafting efforts to balance both life domains and to study relationships with outcomes relevant to employee health and well-being. (shrink)

Shaping off-job life is becoming increasingly important for workers to increase and maintain their optimal functioning. Proactively shaping the job domain has been extensively studied, but crafting in the off-job domain has received markedly less research attention. Based on the Integrative Needs Model of Crafting, needs-based off-job crafting is defined as workers’ proactive and self-initiated changes in their off-job lives, which target psychological needs satisfaction. Off-job crafting is posited as a possible means for workers to fulfill their needs and enhance (...) well-being and performance over time. We developed a new scale to measure off-job crafting and examined its relationships to optimal functioning in different work contexts in different regions around the world. Furthermore, we examined the criterion, convergent, incremental, discriminant, and structural validity evidence of the Needs-based Off-job Crafting Scale using multiple methods. The results showed that off-job crafting was related to optimal functioning over time, especially in the off-job domain but also in the job domain. Moreover, the novel off-job crafting scale had good convergent and discriminant validity, internal consistency, and test–retest reliability. To conclude, our series of studies in various countries show that off-job crafting can enhance optimal functioning in different life domains and support people in performing their duties sustainably. Therefore, shaping off-job life may be beneficial in an intensified and continually changing and challenging working life. (shrink)

Newly edited by Konrad Koerner (University of Ottawa), with an introduction by Clemens Knobloch (Universitat Siegen)The importance of Wegener's Untersuchungen uber die Grundfragen des Sprachlebens can only be compared to that of Karl Buhler's Sprachtheorie. Even now, however, Wegener's work remains virtually unknown to the English speaking world. Wegener's main work was published in 1885. It has its origin in two lectures given in 1883 and 1884 at school teacher meetings held in the Magdeburg area and it still recalls those (...) original occasions and maintains much of the oral style. Part of the volume treats the subject in a systematic and theoretical manner; other sections contain vivid examples and are characterized by a considerable didactic effort. The book is held together by leitmotif-questions, such as 'How do we understand language?' and 'How does language function as a means of everyday communication?'. We witness the experiences of the talented school teacher and the observations of the innovative dialect researcher combined, condensed, and conceptually ordered.In spite of the relatively unsystematic form of presentation, the book remains thoroughly consistent in thought and argument. In the Untersuchungen we have before us the outline of a communicative and functional view of language structure, of the analysis of speech, and of semantics. (shrink)

2020 CHOICE Outstanding Academic Title In this book, Philipp von Wussow argues that the philosophical project of Leo Strauss must be located in the intersection of culture, religion, and the political. Based on archival research on the philosophy of Strauss, von Wussow provides in-depth interpretations of key texts and their larger theoretical contexts. Presenting the necessary background in German-Jewish philosophy of the interwar period, von Wussow then offers detailed accounts and comprehensive interpretations of Strauss's early masterwork, Philosophy and Law, (...) his wartime lecture "German Nihilism," the sources and the scope of Strauss's critique of modern "relativism," and a close commentary on the late text "Jerusalem and Athens." With its rare blend of close reading and larger perspectives, this book is valuable for students of political philosophy, continental thought, and twentieth-century Jewish philosophy alike. It is indispensable as a guide to Strauss's philosophical project, as well as to some of the most intricate details of his writings. (shrink)

This study aims at justifying one of Gilbert Durand’s postulates according to which all imaginaire (as a result of mental imagery) is anchored in our physiology but by directing it rather now towards our neurophysiology. New advances in neurobiology, connectome and neurogenomics lead to rethinking the framework of psychic activity and the induction of neural images.

This is a study that investigated the extent of use of the three principles of ethics – utility, morality, and justice – in managerial ethical decision making, in addition to the personal attitude towards them. It involved undergraduate and graduate business students (total N=163) from the Olayan School of Business in the American University of Beirut, Lebanon. Two kinds of measurements were done: self assessment, and testing with the Saschkin’ s Managerial Value Profile (1997). It showed that morality was the (...) overriding ethical principle used, especially in the graduate group (professionals). Business students still believed in the justice system despite the weakness of the country’s law. Utility was the least used, although males were found to be more utilitarian than females. Finally there was no relation between personal attitudes toward the three ethical principles, and the intentional behavior when faced with ethical dilemmas. The findings were discussed and recommendations were given. (shrink)

La naissance du CRI à Grenoble doit être replacée dans le contexte intellectuel de la nouvelle critique des années 1960. Les trois courants dominants du matérialisme historique, de la psychanalyse freudienne et du structuralisme ont alors été dépassés par le CRI au profit d’un « nouvel esprit anthropologique » qui privilégiait la réalité sensible des images au détriment des idéologies réductrices. Les intellectuels des villes ont perdu le lien charnel avec une civilisation rurale et un mode de vie ayant façonné (...) notre langue, nos croyances et nos fêtes, ainsi que des artisanats séculaires. Le médiéviste peut encore retrouver le lien avec cette mémoire du temps. Mais s’il n’a pas conservé une âme païenne et un esprit paysan, il est condamné à la posture post-moderne. Penser la culture occidentale en contournant ou ignorant le Moyen Âge n’est qu’une imposture. Un exemple de longue vie des images montre l’importance des relais culturels qui relativise toute théorie préconçue des archétypes. The birth of the CRI in Grenoble is replaced in the intellectual context of new criticism of the 1960s. The three mainstream have been overtaken by the CRI in favour of a “new anthropological spirit” that emphasizes the sensible reality of images at the expense of reducing ideologies. The modern scholars of the cities have lost the carnal connection with a rural civilization and a way of life that have shaped our language, our ancient beliefs and feasts and also centuries-old handicrafts. The medievalist can find the link with this memory of time. But if he has lost a pagan soul and a spirit of peasant, he is sentenced to a post-modern posture. Thinking Western culture in bypassing or ignoring the middle ages appears like a mere sham. An example of long-life images stresses the importance of cultural relays against all preconceived theory of the archetypes. (shrink)

There are various conceptions of objectivity, a characteristic of the scientific enterprise, the most fundamental being objectivity as faithfulness to facts. A brute fact, which happens independently from us, becomes a scientific fact once we take cognisance of it through the means made available to us by science. Because of the complex, reciprocal relationship between scientific facts and scientific theory, the concept of objectivity as faithfulness to facts does not hold in the strict sense of an aperspectival faithfulness to brute (...) facts. Nevertheless, it holds in the large sense of an underdetermined faithfulness to scientific facts, as long as we keep in mind the complexity of the notion of scientific fact (as theory-laden), and the role of non-factual elements in theory choice (as underdetermined by facts). Science remains our best way to separate our factual beliefs from our other kinds of beliefs. (shrink)

We have entered a new long-term war regime. This regime is multiform, and deployed on two mutually interpenetrating fronts: one internal, the other external. The military and the forces of a law and order » cooperate with each other to face a supposed common enemy: international terrorism, both actual and potential. If, in this war regime, the American government occupies a leadership position, several other governments are engaged at the sane level, France and Russia amongst them. This state of affairs (...) cannot be reduced to a simple model of American imperialism. This article argues that the principal cause is at once the deepest and largest: it reflects the fear of globality, of the subversive emergence of a humanity at once globalised and mixed, which in multiple ways, shifts future prospects: shaking up dominations, confronting the big, global problems, without playing the game of conflicts of force and territory. It is this, fear which, whilst it motivates those promoting this new regime, also poses to us, a real challenge: that of expressing, more than they can suppress, the virtualities of this globality. (shrink)

This paper concerns Aristotle's kind‐crossing prohibition. My aim is twofold. I argue that the traditional accounts of the prohibition are subject to serious internal difficulties and should be questioned. According to these accounts, Aristotle's prohibition is based on the individuation of scientific disciplines and the general kind that a discipline is about, and it says that scientific demonstrations must not cross from one discipline, and corresponding kind, to another. I propose a very different account of the prohibition. The prohibition is (...) based on Aristotle's scientific and metaphysical essentialism, according to which a scientific demonstration must take as its starting point a set of per se properties of a subject, if these make up a single, unitary definition. The subject of demonstration here is a kind, although not the general kind associated with a discipline, but rather the particular kind that the particular demonstration is about. (shrink)

According to one productive and influential approach to cognition, categorization, object recognition, and higher level cognitive processes operate on a set of fixed features, which are the output of lower level perceptual processes. In many situations, however, it is the higher level cognitive process being executed that influences the lower level features that are created. Rather than viewing the repertoire of features as being fixed by low-level processes, we present a theory in which people create features to subserve the representation (...) and categorization of objects. Two types of category learning should be distinguished. Fixed space category learning occurs when new categorizations are representable with the available feature set. Flexible space category learning occurs when new categorizations cannot be represented with the features available. Whether fixed or flexible, learning depends on the featural contrasts and similarities between the new category to be represented and the individual's existing concepts. Fixed feature approaches face one of two problems with tasks that call for new features: If the fixed features are fairly high level and directly useful for categorization, then they will not be flexible enough to represent all objects that might be relevant for a new task. If the fixed features are small, subsymbolic fragments (such as pixels), then regularities at the level of the functional features required to accomplish categorizations will not be captured by these primitives. We present evidence of flexible perceptual changes arising from category learning and theoretical arguments for the importance of this flexibility. We describe conditions that promote feature creation and argue against interpreting them in terms of fixed features. Finally, we discuss the implications of functional features for object categorization, conceptual development, chunking, constructive induction, and formal models of dimensionality reduction. Key Words: concept learning; conceptual development; features; perceptual learning; stimulus encoding. (shrink)

This article discusses Sven Ove Hansson’s corpus model for the influence of values (in particular, non-epistemic ones) in the hypothesis acceptance/rejection phase of scientific inquiry. This corpus model is based on Hansson’s concepts of scientific corpus and science ‘in the large sense’. I first present Hansson’s corpus model of value influence with some introductory comments about its origins, a detailed presentation of the model with a new terminology, an analysis of its limits, and an appreciation of its handling of controversial (...) non-epistemic values. I conclude that it is a very good candidate for managing value influence, because contrary to other models in the literature it is fairly simple, it provides a universal and systematic procedure for dealing with values, and it syste- matically preserves the epistemic integrity of science. I then study some difficulties associated with the model’s central feature of taking the maximum level of evidence required by the applications of a claim in order for the latter to enter the scientific corpus: the difficulty to identify this maximum requirement; the non-optimality of this requirement with respect to other less demanding requirements; the potentially detrimental consequences of the preference for false negatives over false positives on which it relies; and the issue of whether there can nevertheless be requirements higher than this maximum. I show that these issues may potentially challenge the corpus model. Finally, I call for empirical work (in particular, an investigation of scientists’ and engineers’ own normative views) in order to better assess these issues. (shrink)

Polysemous concepts with multiple related meanings pervade natural languages, yet some philosophers argue that we should eliminate them to avoid miscommunication and pointless debates in scientific discourse. This paper defends the legitimacy of polysemous concepts in science against this eliminativist challenge. My approach analyses such concepts as patchworks with multiple scale-dependent, technique-involving, domain-specific and property-targeting uses (patches). I demonstrate the generality of my approach by applying it to "hardness" in materials science, "homology" in evolutionary biology, "gold" in chemistry and "cortical (...) column" in neuroscience. Such patchwork concepts are legitimate if the techniques used to apply them produce reliable results, the domains to which they are applied are homogenous, and the properties they refer to are significant to describe, classify or explain the behavior of entities in the extension of the concept. By following these normative constraints, researchers can avoid miscommunication and pointless debates without having to eliminate polysemous patchwork concepts in scientific discourse. (shrink)

ABSTRACTWhat is the relation between ethical reflection and moral behavior? Does professional reflection on ethical issues positively impact moral behaviors? To address these questions, Schwitzgebel and Rust empirically investigated if philosophy professors engaged with ethics on a professional basis behave any morally better or, at least, more consistently with their expressed values than do non-ethicist professors. Findings from their original US-based sample indicated that neither is the case, suggesting that there is no positive influence of ethical reflection on moral action. (...) In the study at hand, we attempted to cross-validate this pattern of results in the German-speaking countries and surveyed 417 professors using a replication-extension research design. Our results indicate a successful replication of the original effect that ethicists do not behave any morally better compared to other academics across the vast majority of normative issues. Yet, unlike the original study, we found mixed results o... (shrink)

The focus of this paper are the ethical, legal and social challenges for ensuring the responsible use of “big brain data”—the recording, collection and analysis of individuals’ brain data on a large scale with clinical and consumer-directed neurotechnological devices. First, I highlight the benefits of big data and machine learning analytics in neuroscience for basic and translational research. Then, I describe some of the technological, social and psychological barriers for securing brain data from unwarranted access. In this context, I then (...) examine ways in which safeguards at the hardware and software level, as well as increasing “data literacy” in society, may enhance the security of neurotechnological devices and protect the privacy of personal brain data. Regarding ethical and legal ramifications of big brain data, I first discuss effects on the autonomy, the sense of agency and authenticity, as well as the self that may result from the interaction between users and intelligent, particularly closed-loop, neurotechnological devices. I then discuss the impact of the “datafication” in basic and clinical neuroscience research on the just distribution of resources and access to these transformative technologies. In the legal realm, I examine possible legal consequences that arises from the increasing abilities to decode brain states and their corresponding subjective phenomenological experiences on the hitherto inaccessible privacy of these information. Finally, I discuss the implications of big brain data for national and international regulatory policies and models of good data governance. (shrink)

This article explores the question of how to understand social media following the Habermasian theory of the structural transformation of the public sphere. We argue for a return to political-economic fundamentals as the basis for analysing the public sphere and seek to establish a characteristic connection between digital-behavioural control and singularised audiences in the context of proprietary markets. In the digital constellation, it is less a matter of immobilising the citizen as a consumer but rather of their political activation – (...) albeit in conditions under which commercial interests have primacy: privatisation without privatism. (shrink)

William Alston’s argument against the deontological conception of epistemic justification is a classic—and much debated—piece of contemporary epistemology. At the heart of Alston’s argument, however, lies a very simple mistake which, surprisingly, appears to have gone unnoticed in the vast literature now devoted to the argument. After having shown why some of the standard responses to Alston’s argument don’t work, we elucidate the mistake and offer a hypothesis as to why it has escaped attention.

Developing tools is a crucial aspect of experimental practice, yet most discussions of scientific change traditionally emphasize theoretical over technological change. To elaborate on the role of tools in scientific change, I offer an account that shows how scientists use tools in exploratory experiments to form novel concepts. I apply this account to two cases in neuroscience and show how tool development and concept formation are often intertwined in episodes of tool-driven change. I support this view by proposing common normative (...) principles that specify when exploratory concept formation and tool development succeed to initiate scientific change. (shrink)

First, the demonstration of Bell's theorem, i.e., of the nonlocal character of quantum theory, is spelled out using the EPR criterion of reality as premises and a gedankenexperiment involving two particles. Then, the EPR criterion is extended to include quantities predicted almostwith certainty, and Bell's theorem is demonstrated on these new premises. The same experiment is used but in conditions that become possible in real life, without the requirements of ideal efficiencies and zero background. Very high efficiencies and low background (...) are needed, but these requirements may be met in the future. (shrink)

Animal research suggests that central serotonergic neurons are involved in behavioral suppression, particularly anxiety-related inhibition. The hypothesis linking decreased serotonin transmission to reduced anxiety as the mechanism in the anxiolytic activity of benzodiazepines conflicts with most clinical observations. Serotonin antagonists show no marked capacity to alleviate anxiety. On the other hand, clinical signs of reduced serotonergic transmission (low 5-HIAA levels in the cerebrospinal fluid) are frequently associated with aggressiveness, suicide attempts, and increased anxiety. The target article attempts to reconcile such (...) human and animal findings by investigating whether anxiety reduction or increased impulsivity is more Likely to account for animal behavioral changes associated with decreased serotonergic transmission. The effects of manipulating central serotonin in experimental anxiety paradigms in animals (punishment, extinction, novelty) are reviewed and compared with the effects of antianxiety drugs. Anxiety seems neither necessary nor sufficient to induce control by serotonergic neurons on behavior. Further evidence suggests that behavioral effects of anxiolytics thought to be mediated by decreases in anxiety are not caused by the ability of these drugs to reduce serotonin transmission. Blockade of serotonin transmission, especially at the level of the substantia nigra, results in a shift of behavior toward facilitation of responding. This behavioral shift is particularly marked when there is competition between acting and restraining response tendencies and when obstacles prevent the immediate attainment of an anticipated reward. It is proposed that serotonergic neurons are involved not only in behavioral arousal but also in enabling the organism to arrange or tolerate delay before acting. Decreases in serotonin transmission seem to be associated with the increased performance of behaviors that are usually suppressed, though not necessarily because of the alleviation of anxiety, which might contribute to the suppression. (shrink)

This article presents the Arabic text of al-Q's short geometric treatise, The Book of the centres of the tangent circles on lines, by the method of analysis, with translation and a mathematical commentary. In this treatise al-Q solves by analysis an ordered set of eight problems where the goal is to locate, on a given line, the centre of a circle which is tangent to two given elements, which may be points, straight lines or circles. For example, in the first (...) problem he wanted to find the centre of a circle which contains two given points. In fact, al-Q establishes the locus of the solutions, and this locus can be a straight line or a conic. The treatise is reminiscent of one of the purposes of al-Q's work on the perfect compass, namely to assign to the conics the status of regular lines. (shrink)

We argue that a formal semantics for music can be developed, although it will be based on very different principles from linguistic semantics and will yield less precise inferences. Our framework has the following tenets: Music cognition is continuous with normal auditory cognition. In both cases, the semantic content derived from an auditory percept can be identified with the set of inferences it licenses on its causal sources, analyzed in appropriately abstract ways. What is special about music semantics is that (...) it aggregates inferences based on normal auditory cognition with further inferences drawn on the basis of the behavior of voices in tonal pitch space. This makes it possible to define an inferential semantics but also a truth-conditional semantics for music. In particular, a voice undergoing a musical movement m is true of an object undergoing a series of events e just in case there is a certain structure-preserving map between m and e. Aspects of musical syntax might be derivable on semantic grounds from an event mereology, which also explains some cases in which tree structures are inadequate for music. Intentions and emotions may be attributed at several levels, and we speculate on possible explanations of the special relation between music and emotions. (shrink)

The question of how inequality is generated and how it reproduces over time has been a major concern for social scientists for more than a century. Yet the relationship between inequality and the process of economic development is far from being well understood. These Raffaele Mattioli Lectures have brought together two of the world's leading economists, Professors Philippe Aghion and Jeffrey Williamson, to question the conventional wisdom on inequality and growth, and address its inability to explain recent economic experience. Professor (...) Aghion assesses the affects of inequality on growth, and asks whether inequality matters: if so why is excessive inequality bad for growth, and is it possible to reconcile aggregate findings with macroeconomic theories of incentives? In the second part Jeffrey Williamson discusses the Kuznets hypothesis, and focuses on the causes of the rise of wage and income inequality in developed economies. (shrink)

This book aims to make the pragmatist intellectual framework accessible to organization and management scholars. It presents some fundamental concepts of Pragmatism, their potential application to the study of organizations and the resulting theoretical, methodological, and practical issues.

This paper sets out to evaluate the claim that Aristotle’s Assertoric Syllogistic is a relevance logic or shows significant similarities with it. I prepare the grounds for a meaningful comparison by extracting the notion of relevance employed in the most influential work on modern relevance logic, Anderson and Belnap’s Entailment. This notion is characterized by two conditions imposed on the concept of validity: first, that some meaning content is shared between the premises and the conclusion, and second, that the premises (...) of a proof are actually used to derive the conclusion. Turning to Aristotle’s Prior Analytics, I argue that there is evidence that Aristotle’s Assertoric Syllogistic satisfies both conditions. Moreover, Aristotle at one point explicitly addresses the potential harmfulness of syllogisms with unused premises. Here, I argue that Aristotle’s analysis allows for a rejection of such syllogisms on formal grounds established in the foregoing parts of the Prior Analytics. In a final section I consider the view that Aristotle distinguished between validity on the one hand and syllogistic validity on the other. Following this line of reasoning, Aristotle’s logic might not be a relevance logic, since relevance is part of syllogistic validity and not, as modern relevance logic demands, of general validity. I argue that the reasons to reject this view are more compelling than the reasons to accept it and that we can, cautiously, uphold the result that Aristotle’s logic is a relevance logic. (shrink)

Several disputes about the nature of experience operate under the assumption that experiences have parts, including temporal parts. There's the widely held view, when it comes to temporal experiences, that we should follow James' exhortation that such experiences aren't mere successions of their temporal parts, but something more. And there's the question of whether it is the parts of experiences which determine whole experiences and the properties they have, or whether the determination goes instead from the whole to the parts, (...) as holists have it. But what are parts, or temporal parts, of experiences exactly—what does it mean to say that an experience is “part” of another? Are the participants in those disputes talking about the same thing—is there a univocal notion of “experiential part” available? Are there different kinds of experiential parts? And if there are, is there a systematic way of carving them out? More importantly, how should we conceive of the temporal parts of experiences, and how can we establish that experiences really do have temporal parts, against those who reject the notion? (shrink)

Il est encore paradoxal de reconnaître aux livres des Chroniques le statut d'œuvre littéraire. Longtemps considéré comme de « piètre fiabilité » par rapport au récit parallèle des livres de Samuel et des Rois, ces livres apparaissent aussi sans originalité littéraire par rapport notamment à l'art consommé des récits des livres de Samuel. Dans le sillage de l'Art du récit biblique, de Robert Alter, Ph. Abadie tente de faire ressortir la richesse et la variété des procédés d'écriture qui font du (...) livre des Chroniques une œuvre littéraire véritable. Celle-ci tient fondamentalement à un projet global que révèlent et confirment des « unités kérygmatiques » structurantes et l'ordonnancement de grands ensembles selon divers procédés : technique de répétition et système de périodisation chronologique notamment.It is still paradoxical to recognize the statute of literary work for the books of Chronicles. Long time considered as of “poor reliability” in comparison with the parallel history of the books of Samuel and Kings, these books also seem to be without literary originality in comparison with, notably, the consummate art of the narratives in the books of Samuel. In the wake of “The Art of Biblical Narrative” by Robert Alter, Ph. Abadie tries to bring out the richness and the variety of the writing procedures that make the book of Chronicles a truly literary work. It fundamentally holds to a global project that reveals and confirms some “kerygmatic unities,” structuring and ordering great ensembles according to diverse procedures: especially a technique of repetition and system of chronological periodisation. (shrink)

RésuméDans son traité intituléLe Planisphère, Ptolémée présente une méthode pour représenter une sphère sur un plan, selon des principes compatibles avec ce qu'on nomme aujourd'hui la projection stéréographique. Mais cette dernière ne sera traitée mathématiquement, en tant que telle, que bien plus tard, au IXẹsiècle, dans l'œuvre d'al-Farghānī qui démontrera notamment la propriété fondamentale de cette projection. Ce n'est qu'au Xesiècle qu'al-Qūhī et Ibn Sahl écriront une première théorie générale des projections de la sphère. Cet article analyse les raisons qui (...) permettent d'affirmer que Ptolémée n'a pas conçu mathématiquement de projection, et que cette conception n'a pu être possible qu'avec l'aide de la définition de la surface conique telle qu'Apollonius l'a exposée dans sesConiques. (shrink)

The present article is devoted to two issues. The first is the identification of lead and tin in medieval Arabic alchemy. The second is the investigation of whether Arabic alchemists differentiate between these problematic substances or not. These two issues are investigated in the light of a comparison which is made between the facts that are stated about the two problematic substances in the original Arabic alchemical works and those stated in modern chemical literature. It is proved that Arabic alchemists (...) made a sharp distinction between lead and tin. Also, it becomes clear that these two metals were used in a satisfactory purity in the era of medieval Arabic alchemy. As a consequence of the present study, some conclusions are drawn about the existence of some categories of ‘derivatives’ of fusible bodies in Arabic alchemy which are degenerate to modern categories of oxides, carbonates, etc. (shrink)

The development of geometrical analysis in the 10th century was partly inspired by the reception of the works of Apollonius, which Arab mathematicians translated as early as the preceding century. Al-Qūhī contributed to this development by writing several collections of problems dealing with Apollonian themes and solved by the method of analysis; however, it seems that they do not all occupy the same place in his work. The author gives here the edition, translation, and mathematical commentary of a short work, (...) entitled The determination of two straight lines from a point along a known angle, which presents the particularity of providing problems as geometrical lemmas to other studies. Indeed, al-Qūhī uses two of these lemmas in more complex constructions which belong to his Treatise on the art of the astrolabe. In this same treatise on the astrolabe, as well as in his Treatise on the perfect compass, this scholar also uses as lemmas several problems solved in another of his works, entitled The generation of points on straight lines according to ratios of which the terms are surfaces. This work is unfortunately lost, and all that remains of it are the traces which subsist in other treatises in which it has been used. This study seems to be necessary if one wishes to understand the organization of the work of al-Qūhī, a mathematician of the first rank who was representative of his time. (shrink)