Kincaid argues that molecular biology provides little support for the reductionist program, that biochemistry does not reveal common mechanisms, indeed that biochemical theory obstructs discovery. These assertions clash with biologists' stated advocacy of reductionist programs and their claims about the consequent unity of experimental biology. This striking disagreement goes beyond differences in meaning granted to the terms. More significant is Kincaid's misunderstanding of what biochemists do, for a closer look at scientific practice-- and one of Kincaid's examples--reveals substantial progress toward (...) explaining biological function with biochemical models. With the molecular detail emerge unifying generalizations as well as further aspects of the functional processes. (shrink)

Advances in molecular biology have generally been taken to support the claim that biology is reducible to chemistry. I argue against that claim by looking in detail at a number of central results from molecular biology and showing that none of them supports reduction because (1) their basic predicates have multiple realizations, (2) their chemical realization is context-sensitive and (3) their explanations often presuppose biological facts rather than eliminate them. I then consider the heuristic and confirmational implications of irreducibility and (...) argue that purely biochemical approaches are likely to be unsound and to be unable to confirm an important range of statements. I conclude by sketching criteria for scientific unity that do not entail reducibility and yet leave an important place for identifying underlying mechanisms. Molecular biology, properly understood, provides an excellent paradigm of non-reductive unity between different explanatory levels. (shrink)