Descriptive realism holds that T is true, while normative realism holds that T is warranted. Descriptive pessimism holds that T is false, while normative pessimism holds that T is unwarranted. We should distinguish between descriptive and normative realism because some arguments against scientific realism require that scientific realism be interpreted as descriptive realism, and because scientific realists can retreat from descriptive to normative realism when descriptive realism is under attack. We should also distinguish between descriptive and normative pessimism because some (...) arguments against scientific pessimism require that it be interpreted as descriptive pessimism, and because scientific pessimists can retreat from descriptive to normative pessimism when descriptive pessimism is under attack. -/- . (shrink)

Evolutionary theory coheres with its neighboring theories, such as the theory of plate tectonics, molecular biology, electromagnetic theory, and the germ theory of disease. These neighboring theories were previously unconceived, but they were later conceived, and then they cohered with evolutionary theory. Since evolutionary theory has been strengthened by its several neighboring theories that were previously unconceived, it will be strengthened by infinitely many hitherto unconceived neighboring theories. This argument for evolutionary theory echoes the problem of unconceived alternatives. Ironically, however, (...) the former recommends that we take the realist attitude toward evolutionary theory, while the latter recommends that we take the antirealist attitude toward it. (shrink)

Nickles (2016, 2017, forthcoming) raises many original objections against scientific realism. One of them holds that scientific realism originates from the end of history illusion. I reply that this objection is self-defeating and commits the genetic fallacy. Another objection is that it is unknowable whether our descendants will regard our current mature theories as true or false. I reply that this objection entails skepticism about induction, leading to skepticism about the world, which is inconsistent with the appeal to the end (...) of history illusion. Finally, I argue that we have an inductive rationale for thinking that our descendants will regard our current mature theories as true. (shrink)

The problem of unconceived alternatives can be undermined, regardless of whether the possibility space of alternatives is bounded or unbounded. If it is bounded, pessimists need to justify their assumption that the probability that scientists have not yet eliminated enough false alternatives is higher than the probability that scientists have already eliminated enough false alternatives. If it is unbounded, pessimists need to justify their assumption that the probability that scientists have not yet moved from the possibility space of false alternatives (...) to the possibility space of true alternatives is higher than the probability that scientists have already moved from the former to the latter space. (shrink)