Addressing the Vitalist’s Challenge to Mechanistic Science: Dynamic Mechanistic Explanation

Abstract

Vitalists, especially in the nineteenth century, correctly objected that mechanists’ explanations in biology lacked the resources to explain important features of biological phenomena. As some mechanists, especially Claude Bernard, recognized, the key to addressing these objections was to incorporate in mechanistic explanations the contribution of organization found in living systems. In particular, it is necessary to understand how non-sequential organization (combined with nonlinear operations) enables mechanisms to exhibit the sort of complex behavior, including endogenously generated behavior, exhibited by living organisms. Non-sequential organization poses a serious problem for human understanding, which characterizes the functioning of mechanisms qualitatively in a step-by-step manner. To understand the effects of non-sequential organization between nonlinear operations requires developing mathematical equations to represent the operations and computational simulations using these equations to determine how various components of the mechanism change depending on their own state and those of other components of the mechanism. Further, analyzing the results of these simulations requires appropriate representations such as the phase-space representations employed in dynamical systems theory. Fortunately, mechanistic science can be coupled with dynamical modeling to yield dynamic mechanistic explanations such as those being proposed in systems biology. These hold the promise of explaining the features of biological phenomena on which the vitalists appropriately focused attention.