Astronomer and Marxist Anton Pannekoek was a remarkable figure. As an astronomer, he pioneered quantitative astrophysics and founded the renowned Astronomical Institute in Amsterdam that now carries his name. Before World War I, however, he was employed as a Marxist theorist by the Social Democratic Party of Germany, making him one of the leading intellectuals of international socialism. Because of his significant contributions to such diverse subjects as astronomy and socialism, Pannekoek's life and work uniquely capture the fascinating connections between conceptions of nature, society, and their representations in the early decades of the twentieth century. This book aims to study these connections through the prism of Pannekoek's biography. In doing so, it sets out to explain Pannekoek's particular epistemic, aesthetic, and political choices, while placing them in the broader context of the early twentieth century.Pannekoek tried to keep connections between his political and academic life hidden from view. He had pragmatic reasons to do so. His academic career had suffered from his controversial political reputation on more than one occasion, most dramatically in 1919 when his appointment to deputy director of the Leiden Observatory was obstructed by the Dutch government. 1 From the mid-1910s onwards, he kept his socialist efforts at a distance from his career in astronomy, and even ended up writing two separate autobiographies: one focusing on his career in the labour movement, while the other discussed his astronomical research. 2 Remarkably, this separation has been carried over into scholarship on his life and work. This either discusses Pannekoek's role in the labour

IntroductionIn recent years much research has been conducted on the scholarly or scientific 'persona'. This research expressed different but related ideas of what the concept of a persona actually is and how it can aid in scholarly personae: repertoires and performances of academic identity

Anton Pannekoek (1873-60) was both an influential Marxist and an innovative astronomer. This paper will analyze the various innovative methods that he developed to represent the visual aspect of the Milky Way and the statistical distribution of stars in the galaxy through a framework of epistemic virtues. Doing so will not only emphasize the unique aspects of his astronomical research, but also reveal its connections to his left radical brand of Marxism. A crucial feature of Pannekoek's astronomical method was the active role ascribed to astronomers. They were expected to use their intuitive ability to organize data according to the appearance of the Milky Way, even as they had to avoid the influence of personal experience and theoretical presuppositions about the shape of the system. With this method, Pannekoek produced results that went against the Kapteyn Universe and instead made him the first astronomer in the Netherlands to find supporting evidence for Harlow Shapley's extended galaxy. After exploring Pannekoek's Marxist philosophy, it is argued that both his astronomical method and his interpretation of historical materialism can be seen as strategies developed to make optical use of his particular conception of the human mind.

One of Anton Pannekoek's main scientif ic projects was to provide a representation of the appearance of the Milky Way -an object he believed to be an optical illusion. This paper elucidates how Pannekoek thought the Milky Way appearance was formed by a combination of human psychology and physiology, and why he attributed such significance to it. In doing so, it explores the connections between Pannekoek's scientific methodology and his socialist epistemology. The paper also outlines the various techniques Pannekoek employed in his research. To observe the Milky Way, he used both extrafocal photography and visual observations by himself and others. To represent the results, he combined naturalistic drawings with verbal descriptions, numerical tables, and isophotic diagrams.