Dominique Raynaud

Unlike the physical sciences, sociology is frequently described as an interpretative non-experimental science. Comparative epistemology sheds new light on this claim. 1. Experimentation is not a constant character of the physical sciences; 2. Experimental hypothetical-deductive reasoning, including the test of predictions, is also practicable in sociology. The argument is developed by a detailed step-wise comparison of the prediction of light ray deviation within the Sun’s gravitational field made in 1919 (physics) and the prediction of 8% cosmopolitanism of Cambridge University between 1250 and 1350 (sociology). Extensive analysis of regent masters’ prosopographic notes yields the result of 9.5 percent cosmopolitanism, which is close to the theoretical prediction. Au contraire des sciences physiques, la sociologie est souvent décrite comme une science interprétative et non-expérimentale. L’épistémologie apporte un éclairage nouveau sur cette position : 1) L’expérimentation n’est pas un trait constant des sciences physiques ; 2) Le raisonnement expérimental est également applicable en sociologie. L’argument est développé en comparant en détail le test de la prédiction d’une déviation des rayons lumineux dans un champ de gravitation effectué en 1919 et le test de la prédiction d’un taux de cosmopolitisme de 8 % de l’université de Cambridge dans la période 1250-1350. Le dépouillement des notices prosopographiques des maîtres régents donne un résultat de 9,5 % proche de la prédiction théorique initiale.

Est-il vrai que la science et la technologie forment un tout ? Qu’elles sont unies par des liens constants et nécessaires ? Est-il vrai que le raisonnement technologique prend toujours place dans un contexte industriel ? Que les bio- et nanotechnologies forment la part essentielle des technologies contemporaines ? Que l’application définit adéquatement la relation entre la science et la technologie ? Dans ce livre, Dominique Raynaud examine les limites de chacune de ces idées. Il dresse un panorama complet des problèmes que pose la technologie au moyen d’une étude détaillée des aspects cognitifs, ergologiques, professionnels et juridiques de la relation entre la science et la technologie et met à nu la fiction utilitariste de la prétendue « technoscience ». Tout aussi éloigné de l’apologie que de la critique radicale, ce livre défend une perspective empirique et analytique dans l’étude de la technologie.

Ce livre souhaite montrer, par une comparaison des concepts et des méthodes de la sociologie avec ceux des sciences naturelles, que beaucoup des critères avancés pour doter la sociologie d’un statut épistémologique spécial — et, pour tout dire, souvent dérogatoire — ont un caractère douteux. Éléments d’un discours identitaire partiellement dérivés du Methodenstreit allemand, ces critères — réalisme des théories sociologiques, multiplicité et irréductibilité des paradigmes sociologiques, langage, concepts et programmes inclarifiables, statut logique hors norme des concepts sociologiques, historicité des faits sociaux, inexistence de lois, impossibilité du raisonnement expérimental — ne résistent pas à l’examen critique. Par bien des aspects, la sociologie apparaît être une science ordinaire, ni mieux, ni plus mal lotie que les autres.

This article aims to test a new method of dating optico-astronomical manuscripts, using Ibn al-Haytham’s Epistle on the Shape of the Eclipse as the test case. This work is selected because of indications that its diagrams are based on reality. After clarifying the observation conditions, an astronomical ephemeris is applied to sift through the eclipses that occurred during Ibn al-Haytham’s life throughout the area he is believed to have sojourned. Next, the remaining eclipses are sorted by computing the image projection. The results show that Ibn al-Haytham’s Epistle is likely to have reported the partial solar eclipse of 28 Rajab A.H. 380/21 October 990 in Baṣra. Because this exercise is primarily the test of a new method, this finding should be regarded as a tentative outcome, pending further information.

Brisant l’image idéale de la science consensuelle, les controverses scientifiques sont aujourd’hui devenues un sujet privilégié de la sociologie et de l’histoire des sciences. Elles sont par ailleurs impliquées au cœur des débats sur les méthodes des sciences sociales. Si l’analyse des controverses scientifiques doit beaucoup aux approches inaugurées par les courants relativistes et constructivistes des années 1970-1980, ce livre montre que les études contemporaines ont tout à gagner à réintroduire ce qui a été le principal tabou des trente dernières années: la vérité. Cette conclusion n’est pas le résultat d’une méditation abstraite sur le destin de la sociologie et de l’histoire des sciences. C’est le résultat d’études de cas, portant sur des disciplines telles que la biologie (la thèse des générations spontanées, débattue entre Pasteur et Pouchet), de la médecine (le vitalisme opposé à la médecine expérimentale naissante), de la stéréotomie (les « Guerres perspectives » qui ont agité le Paris des années 1640), de la perspective (la mathématisation de la perspective dans l’Italie du 16e siècle) ou de l’optique (la question de l’intromission, discutée à Oxford). De querelles médiévales à des disputes plus récentes, ces études suivent un même fil conducteur : interroger les rôles de la rationalité, des conventions et des croyances collectives dans la construction des théories scientifiques. L’auteur défend une théorie incrémentaliste du progrès scientifique: pour autant qu’il suive des règles, le débat est un moyen pratique de tester la robustesse d’une théorie et de départager les théories rivales. Le fait que les débats soient souvent marqués par la passion et les émotions est sans intérêt ; l’important est que ces échanges réglés puissent, par la production d’arguments publics, s’approcher de la vérité. C’est une façon de répondre à la question : Pourquoi l’activité scientifique est-elle conflictuelle?

This article studies a fragment on the conic sections that appear in the Codex Atlanticus, fols. 611rb/915ra. Arguments are put forward to assemble these two folios. Their comparison with the Latin texts available before 1500 shows that they derive from the De speculis comburentibus of Alhacen and the De speculis comburentibus of Regiomontanus, joined together in his autograph manuscript. Having identified the sources, and discussed their mathematics, the issue of their transmission is targeted. It is shown that these notes were written by Paolo dal Pozzo Toscanelli, through whom they reached the notebooks of Leonardo da Vinci.

This paper wonders why the Franciscan order took part in the diffusion of optics more than other medieval organisation, both religious and secular. First, clues of this social asymmetry are given. Then, an explanation is put forward: 1. An initial asymmetry existed, by the fact that Grosseteste’s optics was known in the Franciscan studium of Oxford; 2. Since that date, optics spread among the order by a network effect; 3. The rivaltry between the mendicant orders and the homophilia that presided over their conventual libraries’ purchasing policy finally explains why other contemporary organizations, similarly structured, took a smaller interest into optics. In spite of an evident topical connection, this explanation deeply differs from the analysis that has been applied to the Puritans’ and Jesuits’ scientific activity in XVIIth and XVIIIth centuries classical Europe. It does not appeal to the heavy hypothesis of ethos in order to understand scientific development.

Le regain actuel de la sociologie de l'art semble lié à un essai de constitution d'un programme de 'sociologie des œuvres', différencié de la classique sociologie de la production et de la réception artistiques. Ce programme, épigone des théories de la communication, fait l'hypothèse de codes iconiques et plastiques. L'étude des interprétations des rayures de D. Buren et de la pyramide du Grand Louvre de I. M. Pei invalide l'existence de tels codes. La grande variabilité des interprétations est alors expliquée dans le cadre du modèle inférentiel avancé par Sperber et Wilson (1989). L'absence de code et le caractère auto-réfutant de certaines propositions met en doute les chances de succès de ce programme de recherche

In the Quattrocento and Cinquecento the rise of linear perspective caused many polemics which opposed the supporters of an artificial geometrisation of sight to those who were praising the qualities of the drawing according to nature, or were invoking some arguments on a physiological basis. These debates can be grouped according to the four alternatives that form their central concerns: restricted vs. broad field of vision; ocular immobility vs. mobility; curvilinear vs. planar picture; monocular vs. binocular vision. By retaining the first terms of these four alternatives, the history of perspective eliminated many heterodox constructions. From the viewpoint of mathematisation the interest of these debates is that they succeeded, rather than preceded, the adoption of a perspective system defined by the intersection of the visual pyramid. Thus the history of linear perspective constitutes a genuine case of a posteriori justification, or, put differently, it gives us a case of upside down mathematisation.

Considered as an exact science, linear perspective started shortly before 1480, when Piero della Francesca demonstrated for the first time the decrease of apparent magnitudes on the basis of similar triangles. Although medieval and early modern empirical research on perspective is lacking such demonstrative character, we show that it benefited from the influence of optics much earlier than is usually thought, since the first trials of central perspective, two point perspective, or written evidence of a knowledge of optics by practitioners appear at the interface between Duecento and Trecento.

Despite the enthusiasm generated by social constructionism in the study of scientific debates, this contribution shows that – down to their praxeological dimension – the study of scientific controversies can benefit from sources ignored in today sociological literature. The contribution discloses these sources from the works of Shams al-Dīn al-Samarqandī (ca. 1250–ca. 1302), who is the first author to have offered etiquettes of investigation and debate (ādāb al-baḥth wa-al-munāẓara). Consequences are drawn towards constructivist epistemology.

This book explores the interrelationships between optics, vision and perspective before the Classical Age, examining binocularity in particular. The author shows how binocular vision was one of the key juncture points between the three concepts and readers will see how important it is to understand the approach that scholars once took. In the Middle Ages and the Renaissance, the concept of Perspectiva – the Latin word for optics – encompassed many areas of enquiry that had been viewed since antiquity as interconnected, but which a erwards were separated: optics was incorporated into the field of physics (i.e., physical and geometrical optics), vision came to be regarded as the sum of various psycho-physiological mechanisms involved in the way the eye operates (i.e., physiological optics and psychology of vision) and the word ‘perspective’ was reserved for the mathematical representation of the external world (i.e., linear perspective). The author shows how this division, which emerged as a result of the spread of the sciences in classical Europe, turns out to be an anachronism if we confront certain facts from the immediately preceding periods. It is essential to take into account the way medieval scholars posed the problem – which included all facets of the Latin word perspectiva – when exploring the events of this period.

The idea that linear perspective arose only in the West due to the strength of an unusual process of rationalization is denied by the fact that IXth century Islamic scholars had yet a thorough knowledge of the optical and geometrical materials required in perspective. In addition, the process of rationalization was rarely so intense as in that time, because truth uniqueness and scientific communalism were core values of Medieval Islam. The puzzle is not a matter of less or more rationality, but a matter of axiological motives. First, Islamic disregard for perspective is the result of a value-set insofar painters were fearing the hadīths' prohibition, or wished to avoid pretentiousness of their name (muṣawwir). Second, Islamic art did not draw from Qurʿān and hadīth's precepts directly. Third, painters implemented axiological motives, to put iconic practice in accordance with aniconic leanings.

L'étude de la conception architecturale se trouve au carrefour de trois approches: sciences de la conception, psychologie cognitive et architecturologie. Cette dernière tente de modéliser toute la gamme des changements d'état qui apparaissent durant le processus de conception. L'architecturologie sait décrire, au moyen d'échelles, les opérations de conception par lesquelles l'architecte attribue des mesures à l'édifice. Cette modélisation paraît adéquate lorsque le modèle morphologique n'est pas transformé durant le processus de conception (comme dans certains projets de Jørn Utzon ou de Alvar Aalto). Dans d'autres cas – comme dans certains projets de Philibert de l'Orme, Ludwig Mies van der Rohe, Norman Foster – les changements d'état altèrent la structure même du modèle morphologique. De telles transformations ne peuvent plus être décrites par l'échelle. Reprenant une idée de Herbert A. Simon, l'article suggère que la description de ces nouvelles transformations appelle une autre classe d'opérateurs. Ce pourrait être des schèmes, si l'on entend par ce terme la classe des actions prototypiques qui peuvent être exprimées par des verbes fondamentaux comme ouvrir, fermer, séparer, lier, etc.

This article studies the legacy in the West of Abū al-Wafā’s Book on those Geometric Constructions which are Necessary for Craftsmen. Although two-thirds of the geometric constructions in the text also appear in Renaissance works, a joint analysis of original solutions, diagram lettering and probability leads to a robust finding of independent discovery. The analysis shows that there is little chance that the similarities between the contents of Abū al-Wafā’s Book and the works of Tartaglia, Marolois and Schwenter owe anything to historical transmission. The commentary written by Kamāl al-Dīn Ibn Yūnus seems to have had no Latin legacy either.

L'essor de la perspective linéaire a suscité de nombreuses polémiques tout au long du Quattrocento et du Cinquecento, opposant les partisans d'une géométrisation artificialiste de la vision à ceux qui vantaient les qualités du dessin d'après nature ou invoquaient des arguments de nature physiologique. Ces débats peuvent être retracés à partir des quatre alternatives qui en constituent le noyau dur : champ de vision restreint vs. large ; immobilité vs. mobilité oculaire ; tableau plan vs. curviligne ; vision monoculaire vs. binoculaire. En retenant les premiers termes de ces quatre alternatives, l'histoire de la perspective a rejeté de nombreux systèmes hétérodoxes. Du point de vue de la mathématisation, l'intérêt de ces débats tient à ce qu'ils ont succédé, et non précédé, l'adoption du dispositif perspectif comme intersection de la pyramide visuelle. L'histoire de la perspective linéaire offre ainsi un authentique cas de justification a posteriori des fondements ou, pour ainsi dire, de mathématisation à rebours

Contemporary sociology of scientific knowledge (SSK) is defined by its relativist trend. Its programme often calls for the support of philosophers, such as Duhem, Quine, and Wittgenstein. A critical re-reading of key texts shows that the main principles of relativism are only derivable with difficulty. The thesis of the underdetermination of theory doesn't forbid that Duhem, in many places, validates a correspondence-consistency theory of truth. He never said that social beliefs and interests fill the lack of underdetermination. Quine's idea of a selective revision of hypotheses, as well as the neat incompatibility between holism and conventionalism, openly challenges the principles of relativism. Wittgenstein's work, which is not presented in book-form but rather as a tree, forces us to avoid aphoristic choices that credit any text-excising. This remark allows us to tackle the passages that sociological relativism is based on.Mathematical conventions are not anthropological objects. When Wittgenstein examines the "language-games," he only speaks of the functioning of natural language, not to be confused with scientific formal languages. We then should render the formula "language-game" by "well-defined, explicit and compulsory rules of communication", which is a much less attractive formula for relativism. Consequently, there does not exist a real continuity between the epistemologies of Duhem, Quine and Wittgenstein, and the recent works of the SSK.

Why did linear perspective rise in trecento–quattrocento central Italy rather than in any other cultural context? This book provides new insight into the question of the early Italian pioneership in perspective, building on the fact that many references to optics can be found in Renaissance treatises. The fact that most of the medieval optical manuscripts were written by Franciscan masters—the best known among them being Roger Bacon and John Pecham—suggests the need for a closer look at how the medieval universities (studia generalia) operated. An in-depth study of recruitment highlights the exceptional mobility of masters and lectors throughout Europe. However, through the thirteenth and fourteenth centuries, the closer a university was to central Italy, the more cosmopolitan it was. This is a result of the topology of the academic network, since cosmopolitanism depends on the studium’s closeness centrality. This is why, through the masters’ mobility, knowledge circulating in the network preferentially flowed into central Italy.

In view of the progress made in recent decades in the fields of stemmatology and the analysis of geometric diagrams, the present article explores the possibility of establishing the stemma codicum of a handwritten tradition from geometric diagrams alone. This exploratory method is tested on Ibn al-Haytham’s Epistle on the Shape of the Eclipse, because this work has not yet been issued in a critical edition. Separate stemmata were constructed on the basis of the diagrams and the text, and a comparison showed no major differences. The greater reliability of a stemma codicum constructed on the basis of the diagrams rather than the text of a mathematical work is discussed and preliminary conclusions are drawn