This chapter develops a normatively adequate mechanistic model of constitutive explanation (henceforth, mechanistic explanation). The account satisfies two goals: first, to provide an alternative to classical reduction for thinking about constitutive explanation, and second, to show how the systems tradition will have to be amended and revised if it is to offer a normatively adequate account of constitutive mechanistic explanation. The chapter considers the discovery of the mechanism of the action potential and the diverse kinds of experiment required to show that a component is relevant to such a mechanism. The resulting view is a causal-mechanical competitor to reduction as a way of understanding interlevel relationships in neuroscience and beyond.
Keywords: mechanistic model, constitutive explanation, action potential, classical reduction,