An analysis of two heuristic strategies for the development of mechanistic models, illustrated with historical examples from the life sciences. In Discovering Complexity, William Bechtel and Robert Richardson examine two heuristics that guided the development of mechanistic models in the life sciences: decomposition and localization. Drawing on historical cases from disciplines including cell biology, cognitive neuroscience, and genetics, they identify a number of "choice points" that life scientists confront in developing mechanistic explanations and show how different choices result in divergent (...) explanatory models. Describing decomposition as the attempt to differentiate functional and structural components of a system and localization as the assignment of responsibility for specific functions to specific structures, Bechtel and Richardson examine the usefulness of these heuristics as well as their fallibility—the sometimes false assumption underlying them that nature is significantly decomposable and hierarchically organized. When Discovering Complexity was originally published in 1993, few philosophers of science perceived the centrality of seeking mechanisms to explain phenomena in biology, relying instead on the model of nomological explanation advanced by the logical positivists (a model Bechtel and Richardson found to be utterly inapplicable to the examples from the life sciences in their study). Since then, mechanism and mechanistic explanation have become widely discussed. In a substantive new introduction to this MIT Press edition of their book, Bechtel and Richardson examine both philosophical and scientific developments in research on mechanistic models since 1993. (shrink)

In this powerful work of conceptual and analytical originality, the author argues for the primacy of the material arrangements of the laboratory in the dynamics of modern molecular biology. In a post-Kuhnian move away from the hegemony of theory, he develops a new epistemology of experimentation in which research is treated as a process for producing epistemic things. A central concern of the book is the basic question of how novelty is generated in the empirical sciences. In addressing this question, (...) the author brings French poststructuralist thinking—notably Jacques Derrida’s concepts of “différance” and “historiality”—to bear on the construction of epistemic things. Historiographical perspective shifts from the actors’ minds to their objects of manipulation. These epistemological and historical issues are illuminated in a detailed case study of a particular laboratory, that of the oncologist and biochemist Paul C. Zamecnik and his colleagues, located in a specific setting—the Collis P. Huntington Memorial Hospital of Harvard University at the Massachusetts General Hospital of Boston. The author traces how, between 1945 and 1965, this group developed an experimental system for synthesizing proteins in the test tube that put Zamecnik’s research team at the forefront of those who led biochemistry into the era of molecular biology. (shrink)

We argue that intelligible appeals to interlevel causes (top-down and bottom-up) can be understood, without remainder, as appeals to mechanistically mediated effects. Mechanistically mediated effects are hybrids of causal and constitutive relations, where the causal relations are exclusively intralevel. The idea of causation would have to stretch to the breaking point to accommodate interlevel causes. The notion of a mechanistically mediated effect is preferable because it can do all of the required work without appealing to mysterious interlevel causes. When interlevel (...) causes can be translated into mechanistically mediated effects, the posited relationship is intelligible and should raise no special philosophical objections. When they cannot, they are suspect. (shrink)

The concept of mechanism is analyzed in terms of entities and activities, organized such that they are productive of regular changes. Examples show how mechanisms work in neurobiology and molecular biology. Thinking in terms of mechanisms provides a new framework for addressing many traditional philosophical issues: causality, laws, explanation, reduction, and scientific change.

Philosophers of science typically associate the causal-mechanical view of scientific explanation with the work of Railton and Salmon. In this paper I shall argue that the defects of this view arise from an inadequate analysis of the concept of mechanism. I contrast Salmon's account of mechanisms in terms of the causal nexus with my own account of mechanisms, in which mechanisms are viewed as complex systems. After describing these two concepts of mechanism, I show how the complex-systems approach avoids certain (...) objections to Salmon's account of causal-mechanical explanation. I conclude by discussing how mechanistic explanations can provide understanding by unification. (shrink)

In the 1930s Warburg's spare prose and disciplined respect for the facts set the style for a new generation of biochemists who had not known the conceptual revolutions of earlier years. Led by Warburg, they rejected the excesses of the colloid school and the false starts of the teens and twenties. Talk of active structure virtually disappeared as chemists began to identify enzymes, coenzymes, vitamins, and hormones. In the gradual transformation of the Atmungsferment from an ironcolloid complex to a specific (...) haem-protein, the roots of Warburg's inspiration were readily forgotten-the richer and more varied intellectual currents of the early decades of biochemistry. Experimental cytology and pharmacology were important strands. Most of what Warburg was doing on narcosis from 1908 to 1912 was typical of this school. He was deeply influenced by Loeb and his theory of the fertilization membrane. In the period from 1900 to 1914 the ups and down of belief in Hofmeister's enzyme theory was an important trend which helped determine the style of biochemistry in later decades. Warburg's conception of the Atmungsferment was shaped by the general reaction c. 1910 against Buchner's optimistic view. Warburg's Heidelberg lecture was framed as an answer to Hofmeister's lecture of 1901 and turned out almost as an imitation or second edition of it. It was a style that was soon out of fashion. The affinity between the early concept of enzymes and the old concept idea of “living protein” should not be neglected in discussions of Warburg's distaste for “enzymology.” The colloid school is too easily dismissed as a mere impediment to the chemical triumphs of the 1930s. Warburg's Atmungsferment was obviously colored by the colloidal cast of biochemical thought in 1912. The Atmungsferment represented, in short, a hybrid transition from the romantic biochemistry of the period 1900–1925 to the mature, classical of the 1930s. It is fascinating precisely because it reflects, and refracts through a unique and powerful mind, the varied local traditions of the early history of modern biochemistry. (shrink)

The discovery that some B vitamins are constituents of respiratory coenzymes led to the development of an interfield theory of the kind discussed by Darden and Maull. In this paper it is shown that the development of a useful interfield connection was made possible by two reconceptualizations: a reconceptualization that united two then-distinct fields giving rise to the concept of vitamins as dietary substances; and another reconceptualization that united two approaches to respiratory metabolism producing the idea that coenzymes are transport (...) vehicles. (shrink)

In the 1950s–60s biochemists searched intensively for a series of high-energy molecules in the cell. Although we now believe that these molecules do not exist, biochemists claimed to have isolated or identified them on at least sixteen occasions. The episode parallels the familiar eighteenth-century case of phlogiston, in illustrating how error is not simply the loss of facts but, instead, must be actively constructed. In addition, the debates surrounding each case demonstrate how revolutionary-scale disagreement is sometimes resolved by differentiating or (...) partitioning empirical domains, rather than by replacement of one theory by another. (shrink)

Paul Boyer shared a Nobel Prize in 1997 for his work on the mechanism of ATP synthase. His earlier work, though (which contributed indirectly to his triumph), included major errors, both experimental and theoretical. Two benchmark cases offer insight into how scientists err and how they deal with error. Boyer's work also parallels and illustrates the emergence of bioenergetics in the second half of the twentieth century, rivaling achievements in evolution and molecular biology.

Between 1940 and 1970 pioneers in the new field of cell biology discovered the operative parts of cells and their contributions to cell life. They offered mechanistic accounts that explained cellular phenomena by identifying the relevant parts of cells, the biochemical operations they performed, and the way in which these parts and operations were organised to accomplish important functions. Cell biology was a revolutionary science but in this book it also provides fuel for yet another revolution, one that focuses on (...) the very conception of science itself. Laws have traditionally been regarded as the primary vehicle of explanation, but in the emerging philosophy of science it is mechanisms that do the explanatory work. Bechtel emphasises how mechanisms were discovered, focusing especially on the way in which new instruments made these inquiries possible. He also describes how new journals and societies provided institutional structure to this new enterprise. (shrink)

Mitchell's formulation of the chemiosmotic theory of oxidative phosphorylation in 1961 lacked any experimental support for its three central postulates. The path by which Mitchell reached this theory is explored. A major factor was the role of Mitchell's philosophical system conceived in his student days at Cambridge. This system appears to have become a tacit influence on his work in the sense that Polanyi understood all knowledge to be generated by an interaction between tacit and explicit knowing. Early in his (...) life Mitchell had evolved a simple philosophy based on fluctoids, fluctids and statids which was developed in a thesis submitted for the Ph.D. at the University of Cambridge, England. This aspect of his work was rejected by the examiners and became a tacit element in his intellectual development. It is argued from his various publications that this philosophy can be traced as an underlying theme behind much of Mitchell's theoretical writing in the 50's leading, through his notion of vectorial metabolism, to the formulation and amplification of the chemiosmotic theory in the sixties. This philosophy formed the basis for Mitchell of his understanding of biological systems and gave him his unique approach to cell biology. (shrink)