This paper argues that Kepler considered his work in optics as part of natural philosophy and that, consequently, he aimed at change within natural philosophy. Back-to-back with John Schuster’s claim that Descartes’ optics should be considered as a natural philosophical appropriation of innovative results in the tradition of practical and mixed mathematics the central claim of my paper is that Kepler’s theory of optical imagery, developed in his Paralipomena ad Vitellionem (1604), was the result of a move similar to Descartes’ (...) by Kepler. My argument consists of three parts. First, Kepler borrowed a geometrical model and experiment of optical imagery from the mélange of mixed and practical mathematics provided in the works of the sixteenth-century mathematicians Ettore Ausonio and Giovanni Battista Della Porta. Second, Kepler criticized the Aristotelian theory of light and he developed his own alternative metaphysics. Third, Kepler used his natural philosophical assumptions about the nature of light to re-interpret the model of image formation taken from Della Porta’s work. Taken together, I portray Kepler’s theory of optical imagery as a natural philosophical appropriation of an innovative model of image formation developed in a sixteenth-century practical and mixed mathematical tradition which was not interested in questioning philosophical assumptions on the nature of light. (shrink)

The new field of the history of knowledge is often presented as a mere expansion of the history of science. We argue that it has a greater ambition. The re‐definition of the historiographical domain of the history of knowledge urges us to ask new questions about the boundaries, hierarchies, and mutual constitution of different types of knowledge as well as the role and assessment of failure and ignorance in making knowledge. These issues have pertinence in the current climate where expertise (...) is increasingly questioned and authority seems to lose its ground. Illustrated with examples from recent historiography of the sixteenth to twentieth centuries, we indicate some fruitful new avenues for research in the history of knowledge. Taken together, we hope that they will show that the history of knowledge could build the expertise required by the challenges of twenty‐first century knowledge societies, just like the history of science, throughout its development as a discipline in the twentieth century, responded to the demands posed by science and society. (shrink)

The Human Animal in Western Art and ScienceLeonardoLeonardo da Vinci: Experience, Experiment, and DesignSeen | Unseen: Art, Science, and Intuition from Leonardo to the Hubble Space Telescope by Martin Kemp; Martin Kemp; Martin Kemp; Martin Kemp.

The Kunstkammer of the Electors of Saxony, founded in Dresden around 1560, housed one of the richest collections of tools and scientific instruments in its day. A close analysis of the optical objects in the collection in the decades around 1600 is undertaken here—in particular, their arrangement by a mathematically trained curator, Lucas Brunn, and their use in an ‘experiment’ by a distinguished visitor, Johannes Kepler. It is argued that the selection, display and use of optical objects within this collection (...) reflect a specific, playful image of optics promoted at the Saxon court.Keywords: Court collections; Optics; Instruments; Perspective; Wonder. (shrink)

In his Paralipomena Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used his (...) report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis . I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics. (shrink)

Name der Zeitschrift: Paragrana Jahrgang: 25 Heft: 1 Seiten: 110-129.

In his Paralipomena Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used his (...) report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis. I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics. (shrink)

Leonardo's drawings of optical machinery have been used as evidence for the claim that Leonardo built machines to make concave mirrors with which he could project images. This paper argues that Leonardo's drawings cannot be used as evidence for this claim. It will be shown that Leonardo used the drawings to communicate with his patrons and craftsmen, to experiment on paper, to record trials with models, and to think about 'theoretical' problems in optics. At both the theoretical and the practical (...) level, Leonardo was only concerned with the burning properties of concave mirrors, not with their imaging properties. The paper will conclude that the drawings of optical machinery allowed Leonardo to differentiate himself from the ordinary mirror-makers in his workshop. The same drawings, however, also forced him to remain within the conceptual framework of perspectivist optics. (shrink)

While Newton tried to make his telescope into a proof of the supremacy of his theory of colours over older theories, his instrument was welcomed as a way to shorten telescopes, not as a way to solve the problem of chromatic aberration. This paper argues that the image published together with the report on Newton’s telescope in Philosophical Transactions (1672) encouraged this reception. The differences between this visualization and other images of Newton’s telescope, especially that published in Opticks (1704), are (...) discussed. This paper shows that the image in Opticks adopted characteristics of a Cartesian program of visualization of machines and instruments which complemented a rhetoric which attributed primacy to theory over practice. The differences between the images in Philosophical Transactions and Opticks are also considered within the broader institutional context of Newton’s attitude towards the Royal Society. (shrink)

In this assessment of the intersection of trade, picturing collections and knowledge?making in Early Modern Antwerp, the focus is on the role of luxury glass, mirror and lens technology and the science of optics. Emphasizing the social ties that facilitated these intersections, it is argued that newly invented luxury goods such as the pictures of collections and the art cabinets allowed Antwerp craftsmen, artists and art dealers to export the message that the material objects in which they traded were objects (...) of knowledge: not to everyone, however, but to those who desired membership of a select community. (shrink)