Abstract

Kyle Stanford (2006) argues that the most serious and powerful challenge to scientific realism has been neglected. The problem of unconceived alternatives (PUA), as he calls it, holds that throughout history scientists have failed to conceive alternative theories roughly equally wellconfirmed (by the available evidence) to the theories of the day and, crucially, that such alternatives eventually were conceived and adopted by some section of the scientific community. PUA is a version of the argument from the underdetermination of theories by evidence (UTE) but departs from it in two significant ways: (i) there is a shift from artificially produced rival theories - of the kind typically talked about in the underdetermination debate - to actual rivals and (ii) there is a shift from empirically equivalent rivals to rivals that are equally well-confirmed by the available evidence at a given point in time. In this talk I will argue that by these shifts Stanford successfully manages to find more historical evidence for PUA (than do proponents of UTE), but only at the expense of making his thesis ineffectual.