ABSTRACT An overview of some of the main modes of making images of natural objects and processes, as they have appeared in the history of science, leads to two main conclusions. First, the dichotomies that have traditionally distinguished, for example, art from science, museums from laboratories, and geometrical from algebraic methods have produced a poverty of understanding of visualization. It is at the intersections of these dichotomies where much of the creative work of science occurs, and it is into those (...) intersections that this Focus section leads us. Second, the section suggests that we need to understand images as arguments. Generalizing, we need to develop a “materialized epistemology” that reunites sensual with ideational knowing. Recent work in the history of science is already pointing the way and producing a dramatically new historiography. (shrink)

ArgumentThe question, how organisms obtain their specific complex and functional forms, was widely discussed during the eighteenth century. The theory of preformation, which was the dominant theory of generation, was challenged by different alternative epigenetic theories. By the end of the century it was the vitalist approach most famously advocated by Johann Friedrich Blumenbach that prevailed. Yet the alternative theory of generation brought forward by Caspar Friedrich Wolff was an important contribution to the treatment of this question. He turned his (...) attention from the properties of matter and the forces acting on it towards the level of the processes of generation in order to explain the constitution of organismic forms. By regarding organic structures and forms to be the result of the lawfulness of ongoing processes, he opened up the possibility of a functional but non-teleological explanation of generation, and thereby provided an important complement to materialist and vitalist approaches. (shrink)

In 1828 Karl Ernst von Baer (1792-1876) published his seminal Über Entwickelungsgeschichte der Thiere. Beobachtung und Reflexion. In the preface he announced that a second volume with one copper plate would be finished 'in a few weeks'. However, it took nine years until the unfinished second volume was released, with four copperplates. In his 'Autobiography', von Baer did not clarify the reasons why he did not finish his research program of comparative embryology. The paper attempts to elucidate them, furnished by (...) archival documents and von Baer's unpublished embryological drawings. Our sketch of a few figures will show that (1) von Baer searched for 'analogies' (homologies) as a unifying principle and (2) explained the mechanisms of embryogenesis by physiological reasoning (electromagnetism). The main objective is to show that technical problems in illustrating and conceptual difficulties impeded von Baer's ambitious research program. (shrink)