Abstract

I raise two challenges for scientific realists. The first is a pessimistic meta-induction, but not of the more common type, which focuses on rejected theories and abandoned entities. Rather, the PMI I have in mind departs from conceptual change, which is ubiquitous in science. Scientific concepts change over time, often to a degree that is difficult to square with the stability of their referents, a sine qua non for realists. The second challenge is to make sense of successful scientific practice that was centered on entities that have turned out to be fictitious.