Séminaire – Doctoral Interdisciplinaire d’histoire et philosophie des Sciences (DISc )

Image et Histoire (Des Sciences)

Image and text are two categories whose distinction is rarely questioned in the practice of historians, particularly historians of science. This distinction is very often already explicit in the sources, however varied they may be. Images are separated from text by more or less strict layout standards.
But this separation into two autonomous semiotic regimes has its limits. Texts are very often constituent elements of images, particularly in scientific sources. Understanding an image is the result of a highly complex interaction between the texts that are integrated into it, the external text that refers to it and the other elements of the image. Furthermore, non-textual representation practices are extremely varied and cannot be approached by a general method that would apply to all of them. For example, the numeric table or the logical dia- gram are not the products of the same kind of iconographic practice as engraving, which in- corporates the rules of perspective and shading.
This complexity and diversity are particularly evident in the scientific context, where dis- course and representations are generally designed to serve a rational, unambiguous and universal message. Moreover, the scientific context also implies certain modes of discourse, some demonstrative, some didactic, some heuristic. The modal approach is therefore also a major challenge for the field of iconography, calling for the development of new tools for the critical analysis of these modes.
In both writing and reading, the use of images takes us into a perceptive and phenomeno- logical universe that transforms the textual object into a material artefact that questions our interactions with the products of writing.

Nicolas Millot (IHPST, Paris 1 – Panthéon Sorbonne)
Defining mathematical diagrams : philosophical and cognitive issues
The importance of diagrams in the history of mathematics has long been recognized by practitioners and historians of mathematics. However, it is only in recent decades that a philosophical reappraisal of the role of dia- grammatical thinking for mathematical thinking has taken place. This reappraisal has several dimensions (this is not a disciplinary split, so these dimensions are in constant interaction) :

1. une dimension historique, dont la fonction générale est de spécifier les différents types d’usage des diagrammes dans l’histoire des mathématiques. Cette approche est particulière- ment bien exemplifiée par la large série d’études sur le rôle des diagrammes dans la géomé- trie d’Euclide, voir, par exemple Manders, (2008), Netz (2003), Panza (2012), Saito (2012).
2.  a philosophical dimension, the general function of which is to define the general type of object considered as a diagram. Two aspects of this type of research can be specified : on one hand, it is about specifying the set of general constraints (perceptual, conceptual) that define a diagram, and on the other hand, it is about specifying the distinctive characteristics of mathematical diagrams in relation to other species of diagrams. An explicit proposal in this direction is that of Giardino (2023).
3. a cognitive dimension, whose general function is to give precise content to the perceptual
   perceptual constraints and cognitive processes that define diagrams and underpin their use, see for example Wagemans (2014).
   The aim of this presentation is to outline some of the epistemological problems posed by inter-actions between these three dimensions. In particular, we will focus on the problems of defining the (informational/physical) format of a diagrammatic object and the (cognitive/historical) basis of diagrammatic cognition.

Elena Danieli (OFFISS — Università di Bologna ; SPHere — Université Paris Cité)
Obstetrical images as portraits of a changing art.How the anatomical plates of 18th-century midwifery manuals reveal new bodies and new didactics of a new science.
The plates published in the French obstetrical manuals of the end of the 18th century show the bone structures of pelvises, the positioning of foetuses and the manoeuvres to facilitate their descent into the vaginal canal. However, a closer look at them reveals how they also illustrate the evolution of the art of midwifery in a period of radical changes in the procedures, the places and the styles in which the art of childbirth was practised. In this talk, the visual apparatus of the obstetrical texts will be considered as an unusual access point to analyse the development of midwifery didactics, the innovation of the methods by which its principles were taught, and the differences in the train- ing of obstetricians and midwives. From rare instances in the manuals to accurate anatomical repre- sentations which are actual works of art, these obstetrical images portray the gradual reconfigura- tion of medical thinking around pregnant bodies and depict graphically the renegotiation of women’s role in society as mothers and as professionals at the turn of the century.

Delphine Bourgouin (Sorbonne Université – UFR d’Histoire de l’Art – Université Paris-Sorbonne – Paris IV)
Polyhedra in mathematical treatises and the arts of the Italian Renaissance
Already, in some manuscripts of Euclid’s Elements, dating from the 12th to 14th centuries, polyhedra represented in perspective were inserted throughout the text. There are numerous examples of this : Ms. Vat. Lat. 7299 and Ms. Ross. 579 in the Vatican Apostolic Library, Plut. 28.2 and Plut. 28.6 in the Laurentian Library. But it was really from the very end of the 15th century, notably with the writings of the mathematicians Luca Pacioli and Piero della Francesca – also a renowned painter – that the polyhedron became a widespread image in scientific works. This talk will focus on four Italian works from the 15th and 16th centuries : 

•  Piero della Francesca’s Libellus de quinque corporibus regularibus, written between 1480 and 1492 ;
•  La Divina proportione by Luca Pacioli – both manuscripts date from 1498, while the first edition was printed in 1509 ;
•  La Pratica della perspectiva by Daniele Barbaro, printed in 1568 ;
•  Lorenzo Sirigatti’s La Pratica delle prospettiva in the 1596 editio princeps, as well as in its three-year earlier manuscript version.
  In each of these works, the representations of geometric solids will be studied in terms of both their mathematical accuracy and their pictorial technique. The link, more or less close, with the text of the treatise will also be questioned.
  Secondly, we’ll look at how the model of the polyhedron circulated between the scientific and artistic spheres during the Renaissance : Plato’s solids and their derivatives were widely represented by artists during this period, both as two-dimensional projections in a variety of media – marquetry, painting, engraving, etc. – and as three-dimensional objects for a variety of uses – sundials, lanterns, inkwells, etc. – in a variety of media. – as three-dimensional objects for a variety of uses – sundials, lanterns, inkwells, etc.
  Finally, a particular type of portrait will be studied : that of the scholar or philosopher, accompanied by one or more polyhedra. Jacopo de’ Barbari’s Portrait of Luca Pacioli (1495) is certainly the most complex example.

Lieu : Salle 628