Themenschwerpunkt 1: Flowers of Passion and Distinction. Practice, Expertise and Identity in Clusius‘ World
Gastherausgeber: Esther van Gelder / Nicolas Robin

Themenschwerpunkt 2: Physics and Dialectical Materialism
Gastherausgeber: Christian Forstner

Fokus – Focus 1

Florike Egmond / Esther van Gelder / Nicolas Robin
Introductory remarks
Seite 9–12

Brian W. Ogilvie
How to write a letter
Humanist correspondence manuals and the late Renaissance community of naturalists
Seite 13–38

Abstract
Humanist scholars from Desiderius Erasmus to Justus Lipsius took correspondence seriously. In treatises on letter-writing they discussed the rhetoric of correspondence, analyzed the distinct kinds of letters, and developed the ideal that correspondence was a sincere, conversational exchange among distant friends. The correspondence of late Renaissance naturalists reveals that this ideal served as a regulative fiction: though often violated in practice, it nonetheless shaped naturalists‘ expectations about how to write letters and how their correspondents should respond. In an era before natural history was professionalized, the humanist ideal of correspondence helped foster and sustain the community of Renaissance natural history.

Sylvia van Zanen
Jacques Plateau and Carolus Clusius
A shared passion for gardens and plants
Seite 39–68

Abstract
For a period of nearly twenty-five years the famous botanist Carolus Clusius (1526–1609) was in close contact with the long-neglected Jacques Plateau († 1608) from Tournai in the southern Netherlands. Some one hundred letters must have been exchanged between the two plant-lovers. Plateau – here newly identified as a treasurer for the Catholic Church and a magistrate in his local Tournai – owned a impressive garden with more than 450 species of plants: two surviving manuscript catalogues give a detailed impression of his diverse collection of garden plants. He was an accurate observer of plants, who contributed much to the knowledge of Clusius and brought many new species to his attention. He also commissioned, forwarded and made original drawings of plants, some of which are here recognized for the first time. Plateau was the most-cited of all of Clusius‘ Correspondents, and by taking a closer look at the contributions that this plant-lover made to the knowledge of the famous botanist, we gain an interesting insight in the crucial exchange of knowledge, information, seeds and plant specimens between scholars and amateurs during the late 16th century.

Valentina Pugliano
Botanici e artigiani a Venezia
I (pochi) amici di Carolus Clusius
Seite 69–93

Abstract
This is an introduction to the world of artisanal contacts of the Flemish botanist Carolus Clusius (1526–1609) within the context of Venice and the Veneto. Despite Clusius‘ renowned generosity and openness to exchanges with tradesmen and empirically-educated naturalists in continental Europe, his direct interactions with apothecaries from the Veneto, and indeed from the Italian peninsula, seem to have been very limited. This article considers some of the reasons for this discrepancy advancing the thesis that behind Clusius‘ disinterest in these individuals lay different natural historical interests and a different conception of exotic nature.

Marrigje Rikken
Abraham Ortelius as intermediary for the Antwerp animal trailblazers
Seite 95–128

Abstract
In this article the renowned cartographer and humanist Abraham Ortelius is presented – for the first time – as an intermediary between natural historians and Antwerp artists engaged in animal series. The humanist circles that he frequented in Antwerp must have brought him in contact with natural historians, as his extant correspondence and album amicorum indicate. As a businessman dealing in prints and drawings, among other things, and a collector himself, he had a large artistic network as well. Thus he was in the perfect position to act as a mediator between natural historians on one hand and artists on the other. However, to be able to understand more fully the central role Ortelius played, it does not suffice to focus solely on his written correspondence and the contributions made by natural historians and artists in his album amicorum. For that reason, this article examines visual sources in depth and it addresses drawn, painted, and printed animal series by artists working in or around Antwerp. Almost all of these artists had direct contact with Ortelius and it is argued that it was Ortelius who brought the artists in contact with each others‘ work. By discussing the dissemination of certain animal motifs, it is possible to discern the importance of the intermediary role that Abraham Ortelius must have played.

Angela Fischel
The „Verae Icones“ of natural philosophy
New concepts of cognition and the construction of visual reality in Conrad Gessner‘s Historia animalium
Seite 129–142

Abstract
This essay examines the philosophical and theoretical contexts of the images in the Historia animalium, a book by the Swiss physician and humanist Conrad Gessner (1516–1565). Gessner‘s Historia animalium is a milestone in the history of zoology. The book is regarded as the first systematic and all-encompassing description of nature. His Latin nomenclature of animals, his critical attitude towards tradition, as well as his appreciation of experience and the use of images, revolutionised early modern zoology and is often interpreted as a break with superstition and mythology. But this heroic portrait of early modern science does not stand up to closer examination. Especially the use and interpretation of images in Gessner‘s Historia follows a much more complex pattern than just documenting visual data instead of myth. In his preface to the Historia animalium Gessner refers to Christian concepts of images and cognition to justify his use of images. In no way this does diminish Gessner‘s achievements; it might lead to a better understanding of an important aspect in the logic of images in early modern science.

Saskia Klerk
Teaching the materiae medicae at Leyden University
Between natural history, botany and the foundations of medicine
Seite 143–171

Abstract
In 1594, the first academic garden in the young Dutch republic was established in Leyden. It was designed by Carolus Clusius (1526–1609) and his assistant, Dirck Cluyt (1546–1598), who supplied most of the plants for the garden from their own collections. This article examines the teaching of materia medica that was performed at the University by medical professor and keeper of the garden Petrus Paaw (1564–1617). Historians have argued about whether to characterise the garden as medical, botanical or even natural historical. Here it will be argued that although people at the time were aware of differences in approach between these disciplines, Paaw did not make a clear choice between them. Using De Materia Medica by Dioscorides (ca. 40–90 AD) to give lectures on herbs, helped Paaw to bring them together. Definite differences in the content of and the motives behind this text and that of the garden, can be recognised as well however. Considering Paaw‘s teaching in this way will help us understand how botany could be introduced at the University as part of the medical curriculum. It will also help elucidate how the particular approach to plants and other natural materials that was developed in the 16th century, affected the way physicians saw and investigated the materials they used as drugs.

Freier Beitrag

Patrick Bungener
Le réseau épistolaire de Candolle à Montpellier
La lettre au service de la botanique et de la carrière académique
Seite 173–188

Abstract
This paper examines the epistolary network of the Swiss botanist Augustin-Pyramus de Candolle (1778–1841) during his stay in the city of Montpellier (France) as director of the botanical garden between 1808 and 1816. It shows that this network may be differentiated into four different networks, each having different functions and connecting different persons or institutions: the first concerns the botanical gardens in Europa for the development of the Montpellier garden, which is also the aim of the second network linking the „amateur botanists“, the third one is related to universitary people (especially working in Montpellier), and the last one with aristocratic and noble people serving Candolle in his aim to be promoted as rector of the Montpellier university. This paper shows also the importance of his Théorie élémentaire de la botanique for supporting his ambitions to be rector of one of the oldest university in Europe.

Fokus – Focus 2

Christian Forstner
Einführung
Seite 191–194

Olival Freire
On the Connections between the Dialectical Materialism and the Controversy on the Quanta
Seite 195–210

Abstract
The controversy over the interpretation of the formalism of quantum mechanics, has been an lasting scientific controversy with strong philosophical overtones as questions at stake concern issues such as realism, objectivity, determinism, instrumentalism, locality and so on. Thus, it comes as no surprise that it also involved Marxist physicists and philosophers. In the 1950s this involvement had its apex with Cold war tension ideological and political connotations and involved first rank physicists, such as Fock, Bohm, Rosenfeld, Blokhintsev, Terletsky, Vigier and Schönberg. Later the subject attracted a renewed interest but the resonance with Marxism faded away. Jammer suggested that the manner in which opposition to the Copenhagen interpretation of quantum mechanics „was fomented and supported by social-cultural movements and political factors, such as the growing interest in Marxist ideology in the West, deserves to be investigated.“ I will argue that while criticizing the Copenhagen interpretation Soviet and Western Marxist physicists played a positive role in the renewal of the research on the foundations of quantum physics, a conclusion standing irrespective of the way in which Marxists made their criticisms in the 1950s. Marxists, however, did not have a unique stand on the quantum controversy. Thus, while speaking of Marxism and quantum controversy is better to use the plural Marxisms rather than the singular Marxism.

Alexei Kojevnikov
Probability, Marxism, and Quantum Ensembles
Seite 211–235

Abstract
This paper establishes a historical and philosophical link between two fundamental twentieth-century scientific debates: the search for mathematical foundations of probability theory and the controversy about the interpretation of quantum theory. Marxist philosophy played a heuristic role in Khinchin‘s approach to probability theory as a science of mass phenomena that also served as the background for Kolmogorov‘s axiomatic definition of probability. Understanding the distinction between statistics and indeterminism was important for Blokhintsev‘s Marxism-inspired „ensemble interpretation“ of quantum mechanics, which also relied on Mandelstam‘s solution of the Einstein-Podolsky-Rosen paradox. These two related cases reveal in a different light the intricacy of the relationships between developments in the mathematical sciences and philosophical / ideological assumptions and arguments.

Anja Skaar Jacobsen
„Strife about Complementarity“ and Léon Rosenfeld‘s Conception of Marxism
Seite 237–251

Abstract
In this paper I discuss the combination of physics and socialism by the Belgian physicist Léon Rosenfeld. Rosenfeld‘s conception of Marxism is analyzed, and I suggest that his focus on epistemology enabled him to combine the complementarity interpretation of quantum mechanics with dialectical materialism. The last part of the paper treats the contests over ideology and scientific values in quantum foundations during the early Cold War, which prompted Rosenfeld to come forward in the public with his own independent Marxist views. In this way, Rosenfeld‘s pragmatic view on dialectical materialism and foundations of quantum physics are compared and contrasted to those of other Marxist scholars notably D. I. Blokhintsev, David Bohm, Martin Strauss, and Vladimir A. Fock.

László Székely
Lajos Jánossy‘s Reformulation of Relativity Theory in the Contexts of „Dialectical Materialism“ and Traditional Scientific Rationalism
Seite 253–270

Abstract
The late Hungarian physicist Lajos Jánossy is respected in international physics first of all for his results achieved in the field of cosmic radiations, but his work in the alternative, Lorentzian tradition of relativity theory is also of historical importance. As an adopted son of the Hungarian Marxist philosopher, Georg Lukács, he was socialised in a left-wing spirit. He formulated a philosophical criticism of Einstein‘s theory in terms of dialectical materialism in the 1950s and 1960s. In contrast to the new Soviet thesis valid in Soviet ideology from 1955, he insisted that the positivist, Machian epistemological foundation determinatively influenced the physical level of Einstein‘s relativity theory and distorted its real physical meaning. He also rejected the anti-commonsense character of Einstein‘s new concepts of space and time and argued for the necessity of a commonsense-conform physics. However, in contrast to the Soviet critics of relativity theory of the Stalinist period, Jánossy never used ideology to destroy the scientific authenticity of Einstein‘s theory, but, accepting the Einsteinian-Lorentzian mathematics as one of the great achievements of the history of physics, he announced and successfully implemented a positive program of a commonsense- conform, non-positivist, Lorentz-based reformulation of the theory. The socialcultural background of Jánossy‘s reformulation of relativity theory is characterised by the strain of two contradictory elements: on the one hand, his left wing, Marxist commitment, on the other, his socialization in Western, „bourgeois“ science and culture. Through a Marxist, „dialectical materialist“ criticism of the positivist, Machian aspects of Einstein‘s theory as well as through his work for a commonsense–conform physics, Jánossy defended not only Marxism but also the classical tradition of scientific rationalism as an essential element of European culture.

Freie Beiträge

Jürgen Teichmann
Eine neue „Landschaft“ des Unsichtbaren
Dunkle Linien im Spektrum der Sterne
Seite 273–325

Abstract
Die dunklen Linien im Spektrum der Sonne und Fixsterne, entdeckt ab 1802 durch William Hyde Wollaston, Joseph Fraunhofer und Johann Lamont, veränderten die Astronomie als Wissenschaft radikal – allerdings erst ab 1859. Kann man diese Entdeckung einer neuen Himmels-“Landschaft“ trotzdem schon parallel zu anderen kulturgeschichtlichen Ereignissen der 1. Hälfte des 19. Jhts interpretieren? Wollastons vereinfachende Schwarz-Weiß Radierung von 1802 ist eine Entschärfung und Verkleinerung des Phänomens. Er sieht vier scharf getrennte Grundfarben, die durch einzelne dunkle Linien voneinander getrennt sind. Fraunhofers berühmte kolorierte Radierung von ca. 1817 ist eine akribisch genaue Darstellung von ästhetischem Anspruch. Sie enthält hunderte dunkler Linien in einem farblich sich kontinuierlich verändernden Spektrum von rot bis violett. Lamonts Fixsternspektren von 1836 sind Bleistiftskizzen aus Beobachtungsbüchern, die die „Merkwürdigkeit“, das heißt das Chaos unterschiedlicher Linienerscheinungen bei verschiedenen Sternen betonen. Allen gemeinsam ist der tastende Versuch, etwas visuell völlig Neues, Unbegreifliches als wissenschaftliches Thema zu etablieren. Sie trafen damit vorbereitetes Terrain in anderen Denkbereichen – bei Alexander von Humboldts Naturverständnis, bei Johann Wolfgang von Goethes Interesse an Licht und Figuren. Zwar wurde Neues, „Unsichtbares“, auch in der etablierten Astronomie immer stärker thematisiert. Spektroskopische Wirklichkeit erforderte aber radikal anderes Sehen, weg vom unmittelbar visuell erfassbaren Bild des Himmels. Das war ein Hauptgrund für die Verzögerung der historischen Entwicklung bis 1859 und der Hauptgrund für die letztlich fehlende geistesgeschichtliche Reflexion bis in das 20. Jahrhundert.