Mechanism

Mechanism

As the brief history of molecular biology showed, molecular biologists discover and explain by identifying and elucidating mechanisms, such as DNA replication, protein synthesis, and the myriad mechanisms of gene expression. The phrase “theory of molecular biology” was not used and for good reason; general knowledge in the field is represented by diagrams of mechanisms. Discovering the mechanism that produces a phenomenon is an important accomplishment for several reasons. First, knowledge of a mechanism shows how something works: elucidated mechanisms provide intelligibility. In some cases, one can literally see how the mechanism works from beginning to end. One can run a simulation in the mind's eye. Second, knowing how a mechanism works allows predictions to be made based upon the regularity in mechanisms. One may be able to say how a mechanism would work, if another instance is encountered, or if conditions or inputs are changed. Thirdly, knowledge of mechanisms potentially allows one to intervene to change what the mechanism produces, to manipulate its parts to construct experimental tools, or to repair a broken, diseased mechanism. In short, knowledge of elucidated mechanisms provides understanding, prediction, and control. Given the general importance of mechanisms and the fact that mechanisms play such a central role in the field of molecular biology, it is not surprising that philosophers of biology pioneered analyzing the concept of mechanism.
The new mechanistic perspective in philosophy of science developed, in part, in philosophy of molecular biology (as well as in studies of cell biology and neuroscience). As early as the 1970s, William Wimsatt (1972, 67) said, “At least in biology, most scientists see their work as explaining types of phenomena by discovering mechanisms...” In their seminal book, Discovering Complexity, William Bechtel and Robert Richardson (1993) investigated the roles of decomposition and localization as strategies for discovering mechanisms. Richard Burian (1993, 389) noted that molecular biology “mainly studies molecular mechanisms,” and expanded this perspective in Burian (2005).