The concept of mechanism in biology has three distinct meanings. It may refer to a philosophical thesis about the nature of life and biology (i.e., ‘mechanicism’ or ‘mechanistic biology’), to the structure and internal workings of a machine-like system (i.e., ‘machine mechanism’), or to an epistemic device that facilitates the explanation of a phenomenon of interest (i.e., ‘causal mechanism’). In this talk I trace the conceptual evolution of ‘mechanism’ in the history of biological thought, and examine how the three meanings of this term have come to be featured in the philosophy of biology, situating the new ‘mechanismic program’ in this context. I argue that the leading advocates of the mechanismic program (e.g., Craver, Darden, Bechtel, etc.) inadvertently conflate the different senses of ´mechanism.´ Specifically, they all inappropriately endow causal mechanisms with the ontic status of machine mechanisms, and this invariably results in problematic accounts of the role played by ‘mechanism-talk’ in scientific practice. Ultimately, I suggest that for effective analyses of the concept of mechanism, causal mechanisms need to be distinguished from machine mechanisms, and the new mechanismic program in the philosophy of biology needs to be demarcated from the traditional concerns of mechanistic biology.
Daniel J. Nicholson is currently completing his PhD in the philosophy of biology at the University of Exeter. He holds MDs in the history and philosophy of science (University of Leeds) and molecular and cellular biology (University of Bath). His doctoral thesis presents a critical examination of various strains of mechanistic thinking in biology. Daniel has published on the history and philosophy of cell theory and is currently co-editing a special issue on normativity, teleology, and mechanism in biological explanation. His postdoctoral research plans involve using the critique of mechanistic biology developed in his thesis to articulate an organicist understanding of living systems that positively asserts their ontological distinctiveness (grounded in their intrinsically purposive autopoietic organization) and vindicates their central place in biological theory. Nicholson also has longstanding interests in the history of theoretical biology and in general philosophy of science..