The ArgumentIn this essay I will sketch a few instances of how, and a few forms in which, the “invisible” became an epistemic category in the development of the life sciences from the seventeenth century through the end of the nineteenth century. In contrast to most of the other papers in this issue, I do not so much focus on the visualization of various little entities, and the tools and contexts in which a visual representation of these things was realized. (...) I will be more concerned with the basic problem of introducing entities or structures that cannot be seen, as elements of an explanatory strategy. I will try to review the ways in which the invisibility of such entities moved from the unproblematic status of just being too small to be accessible to the naked or even the armed eye, to the problematic status of being invisible in principle and yet being indispensable within a given explanatory framework. The epistemological concern of the paper is thus to sketch the historical process of how the “unseen” became a problem in the modern life sciences. The coming into being of the invisible as a space full of paradoxes is itself the product of a historical development that still awaits proper reconstruction. (shrink)

The employment of the cell-concept is examined in the context of some selected cell-theories ; for these cases it is argued that the logical structures of their respective cell-concepts are strongly interrelated, e. g., in some respect the theory of Schwann is an inversion of that of Meyen. Nevertheless, Meyen's theory is distinguished by operating with an idealized cell-structure that is considered to compromise the necessary constituents for maintaining the diverse cell-functions, whereas in Schwann's theory this clear >cell-structure-to-cell-function< relationship is (...) preserved only for the very beginning of cell-formation; the remaining segments of the cell's life-cycle are modelled according to both a natural-historical and a physicochemical atomistic research programme; thus, this hybrid conception cannot be classified to be a pure cell-physiological one. Other cell-theories from between 1840 and about 1900 – among which are the theories of the »Energide« or the »Mikromer« – do not add to the beforehand elucidated logical structure of those earlier concepts. As a complement to all these cell-theoretical conceptions a more precise understanding of protoplasmatic theories may be obtained. Since, basically, they assumed the possibility of a substance endowed with morphogenetic functions they got into the historically well documented conflict with cell-theories relating structure to function. Finally, the four-fold mode of meaning of the cell-concept is summarized and its relevance for fundamental problems in the biological debate or for questions concerning the reality of biological objects is discussed. (shrink)

Although the cell is commonly addressed as the unit of life, historians and philosophers have devoted relatively little attention to this concept in comparison to other fundamental concepts of biology such as the gene or species. As a partial remedy to this neglect, we introduce the cell as a major point of connection between various disciplinary approaches, epistemic strategies, technological vectors and overarching biological processes such as metabolism, growth, reproduction and evolution. We suggest that the role of the cell as (...) a nexus forms the basis for a new philosophical and historical appreciation of cell biology. This perspective focuses less on the cell as a well-defined, stable object and places more emphasis on its role as a mediator of fundamental biological processes. (shrink)

In 1900, the physicist Henri Bénard exhibited the spontaneous formation of cells in a layer of liquid heated from below. Six or seven decades later, drastic reinterpretations of this experiment formed an important component of ‘chaos theory’. This paper therefore is an attempt at writing the history of this experiment, its long neglect and its rediscovery. It examines Bénard’s experiments from three different perspectives. First, his results are viewed in the light of the relation between experimental and mathematical approaches in (...) fluid mechanics, leading to a re-examination of the long-term reception of Bénard’s results among fluid dynamicists up to the chaos craze, whereby the traditional emphasis placed on mathematical physics is counterbalanced by greater attention to experimental approaches. Second, we focus on Bénard’s own way of using his results as analogies that could help grasp something about the reason why inorganic matter may structure itself in ways reminiscent of living forms. This is shown to resonate strongly with Prigogine’s work in the 1960s and 1970s. Third, Bénard’s adoption of the cinematograph as his preferred experimental instrument is interpreted as having reinforced his long-misunderstood belief that he had exhibited a form of self-organization essential to the understanding of life.Keywords: Bénard cells; Henri Poincaré; Chaos; Fluid mechanics; Cinematograph; Self-organization. (shrink)

In this study the notion of mechanistic entities is analyzed as it has been conceptualized by Hermann Lotze in his article Life. Vital Force (1842), the metaphysical foundation of which has recourse to his Metaphysik (1841) and Logik (1843). According to Lotze, explanations in the sciences are arguments which have a syntactic and a semantic structure—similar to that which became later known as the DN-model of explanation. The syntactic structure is delineated by ontological forms, the semantic by cosmological ones; the (...) latter comprise the preconditions for the construction of appearances in accord with the ontological forms. Mechanisms are embedded into this logical framework by representing the more complex spatio-temporal arrangements of cosmological entities. The coordinated model of a mechanism is a reductive type of explanation. This study also demonstrates how Lotze made use of his concept of mechanisms in order to explain law-like and probabilistic events in organic and inorganic nature, thereby establishing an original ‘oligomeric’ (i. e., a fraction of the parts of a system determines its development) variant of a preformative theory of ontogenesis which anticipates modern concepts of genetic determination. In this context, Lotze alludes to paradigms of dissipative structures. The relevance of these reflections for subsequent theories is shown by contrasting them with Schrödinger’s theory of organisms. Finally, a comparison of some aspects of Lotze’s concept of mechanisms with equivalent aspects of current normative approaches confirms that essential elements of the latter versions can be retrieved in the former one. Above that, Lotze employs the teleological aspect of ontological forms in order to determine the extent of the mechanistic system under consideration. He further differentiates three modal states of mechanisms and includes a concept to explain exceptions or irregularities. The concept of ‘activity’ is strictly excluded from his account and shown to be a metaphysical illusion. (shrink)

Biological atomism postulates that all life is composed of elementary and indivisible vital units. The activity of a living organism is thus conceived as the result of the activities and interactions of its elementary constituents, each of which individually already exhibits all the attributes proper to life. This paper surveys some of the key episodes in the history of biological atomism, and situates cell theory within this tradition. The atomistic foundations of cell theory are subsequently dissected and discussed, together with (...) the theory’s conceptual development and eventual consolidation. This paper then examines the major criticisms that have been waged against cell theory, and argues that these too can be interpreted through the prism of biological atomism as attempts to relocate the true biological atom away from the cell to a level of organization above or below it. Overall, biological atomism provides a useful perspective through which to examine the history and philosophy of cell theory, and it also opens up a new way of thinking about the epistemic decomposition of living organisms that significantly departs from the physicochemical reductionism of mechanistic biology. (shrink)

In this paper I offer an analysis of causation based upon a theory of mechanisms-complex systems whose internal parts interact to produce a system's external behavior. I argue that all but the fundamental laws of physics can be explained by reference to mechanisms. Mechanisms provide an epistemologically unproblematic way to explain the necessity which is often taken to distinguish laws from other generalizations. This account of necessity leads to a theory of causation according to which events are causally related when (...) there is a mechanism that connects them. I present reasons why the lack of an account of fundamental physical causation does not undermine the mechanical account. (shrink)

The cell is not only the structural, physiological, and developmental unit of life, but also the reproductive one. So far, however, this aspect of the cell has received little attention from historians and philosophers of biology. I will argue that cell theory had far-reaching consequences for how biologists conceptualized the reproductive relationships between germs and adult organisms. Cell theory, as formulated by Theodor Schwann in 1839, implied that this relationship was a specific and lawful one, that is, that germs of (...) a certain kind, all else being equal, would produce adult organisms of the same kind, and vice versa. Questions of preformation and epigenesis took on a new meaning under this presupposition. The question then became one of whether cells could be considered as autonomous agents producing adult organisms of a given species, or whether they were the product of external, organizing forces and thus only a stage in the development of the whole organism. This question became an important issue for nineteenth-century biology. As I will demonstrate, it was the view of cells as autonomous agents which helped both Charles Darwin and Gregor Mendel to think of inheritance as a lawful process. (shrink)

Research in many fields of biology has been extremely successful in decomposing biological mechanisms to discover their parts and operations. It often remains a significant challenge for scientists to recompose these mechanisms to understand how they function as wholes and interact with the environments around them. This is true of the eukaryotic cell. Although initially identified in nineteenth-century cell theory as the fundamental unit of organisms, researchers soon learned how to decompose it into its organelles and chemical constituents and have (...) been highly successful in understanding how these carry out many operations important to life. The emphasis on decomposition is particularly evident in modern cell biology, which for the most part has viewed the cell as merely a locus of the mechanisms responsible for vital phenomena. The cell, however, is also an integrated system and for some explanatory purposes it is essential to recompose it and understand it as an organized whole. I illustrate both the virtues of decomposition (treating the cell as a locus) and recomposition (treating the cell as an object) with recent work on circadian rhythms. Circadian researchers have both identified critical intracellular operations that maintain endogenous oscillations and have also addressed the integration of cells into multicellular systems in which cells constitute units. Ó 2010 Elsevier Ltd. All rights reserved. (shrink)

The term ‘cell’, in addition to designating fundamental units of life, has also been applied since the nineteenth century to technical apparatuses such as fuel and galvanic cells. This paper shows that such technologies, based on the electrical effects of chemical reactions taking place in containers, had a far-reaching impact on the concept of the biological cell. My argument revolves around the controversy over oxidative phosphorylation in bioenergetics between 1961 and 1977. In this scientific conflict, a two-level mingling of technological (...) culture, physical chemistry and biological research can be observed. First, Peter Mitchell explained the chemiosmotic hypothesis of energy generation by representing cellular membrane processes via an analogy to fuel cells. Second, in the associated experimental scrutiny of membranes, material cell models were devised that reassembled spatialized molecular processes in vitro. Cells were thus modelled both on paper and in the test tube not as morphological structures but as compartments able to perform physicochemical work. The story of cells and membranes in bioenergetics points out the role that theories and practices in physical chemistry had in the molecularization of life. These approaches model the cell as a ‘topology of molecular action’, as I will call it, and it involves concepts of spaces, surfaces and movements. They epitomize an engineer’s vision of the organism that has influenced diverse fields in today’s life sciences. (shrink)