The Conscious Mind: In Search of a Fundamental Theory (Philosophy of Mind)

by David J. Chalmers

A reductive explanation of a phenomenon need not require a reduction of that phenomenon, at least in some senses of that ambiguous term. In a certain sense, phenomena that can be realized in many different physical substrates—learning, for example—might not be reducible in that we cannot identify learning with any specific lower-level phenomenon. But this multiple realizability does not stand in the way of reductively explaining any instance of learning in terms of lower-level phenomena.20 Reductive explanation of a phenomenon should also not be confused with a reduction of a high-level theory. Sometimes a reductive explanation of a phenomenon will provide a reduction of a preexisting high-level theory, but other times it will show such theories to be on the wrong track. Often there might not even be a high-level theory to reduce.