Viktor Hamburger was a developmental biologist interested in the ontogenesis of the vertebrate nervous system. A student of Hans Spemann at Freiburg in the 1920s, Hamburger picked up a holistic view of the embryo that precluded him from treating it in a reductionist way; at the same time, he was committed to a materialist and analytical approach that eschewed any form of vitalism or metaphysics. This paper explores how Hamburger walked this thin line between mechanistic reductionism and metaphysical vitalism in (...) light of his work on the factors influencing growth of neurons into limb buds, and the discovery of nerve growth factor, work carried out with Rita Levi-Montalcini and Stanley Cohen. (shrink)

This paper aims to provide a fresh historical perspective on the debates on vitalism and holism in Germany by analyzing the work of the zoologist Hans Spemann (1869–1941) in the interwar period. Following up previous historical studies, it takes the controversial question about Spemann’s affinity to vitalistic approaches as a starting point. The focus is on Spemann’s holistic research style, and on the shifting meanings of Spemann’s concept of an organizer. It is argued that the organizer concept unfolded multiple layers (...) of meanings (biological, philosophical, and popular) during the 1920s and early 1930s. A detailed analysis of the metaphorical dynamics in Spemann’s writings sheds light on the subtle vitalistic connotations of his experimental work. How Spemann’s work was received by contemporary scientists and philosophers is analyzed briefly, and Spemann’s holism is explored in the broader historical context of the various issues about reductionism and holism and related methodological questions that were so prominently discussed not only in Germany in the 1920s. (shrink)

This article explores the collaborative research of the Nobel laureate Hans Spemann (1869–1941) and the Swiss zoologist Fritz Baltzer (1884–1974) on problems at the intersection of development and heredity and raises more general questions concerning science and politics in Germany in the interwar period. It argues that Spemann and Baltzer’s collaborative work made a significant contribution to the then ongoing debates about the relation between developmental physiology and hereditary studies, although Spemann distanced himself from _Drosophila_ genetics because of his anti-reductionist (...) position. The article analyzes how Spemann framed the issues of heredity in terms of an epigenetic principle in the context of his work on the “organizer,” and it explores the experimental dynamics of research on newt merogones carried out by Baltzer in a methodological development of Spemann’s constriction experiments. Finally, these research attempts are discussed as part of a broader “prehistory” of the mid-twentieth century cell nuclear transplantation experiments, which provided the basis for later animal cloning. (shrink)

The term ‘mechanism’ has been used in two quite different ways in the history of biology. Operative, or explanatory mechanism refers to the step-by-step description or explanation of how components in a system interact to yield a particular outcome . Philosophical Mechanism, on the other hand, refers to a broad view of organisms as material entities, functioning in ways similar to machines — that is, carrying out a variety of activities based on known chemical and physical processes. In the early (...) twentieth century philosophical Mechanism became the foundation of a ‘new biology’ that sought to establish the life sciences on the same solid and rigorous foundation as the physical sciences, including a strong emphasis on experimentation. In the context of the times this campaign was particularly aimed at combating the reintroduction of more holistic, non-mechanical approaches into the life sciences . In so doing, Mechanists failed to see some of the strong points of non-vitalistic holistic thinking. The two approaches are illustrated in the work of Jacques Loeb and Hans Spemann. (shrink)