naturalism and evolution is internally dubious or inconsistent. Responses Fitelson and Sober's response In a 1998 paper Branden Fitelson of the University of California, Berkeley and Elliott Sober of the University of Wisconsin–Madison set out to show that the arguments presented by Plantinga contain serious errors. Plantinga construed evolutionary naturalism as the conjunction of the idea that human cognitive faculties arose through evolutionary mechanisms, and naturalism which he equated to atheism. Plantinga tried to throw doubt on this conjunction with a preliminary argument that the conjunction is probably false, and a main argument that it is self-defeating; if you believe it you should stop believing it. First, they criticised Plantinga's use of a Bayesian framework in which he arbitrarily assigned initial probabilities without empirical evidence, predetermining the outcome in favor of traditional theism, and described this as a recipe for replacing any non-deterministic theory in the natural sciences, so that for example a probable outcome predicted by quantum mechanics would be seen as the outcome of God's will. Plantinga's use of R to mean that "the great bulk" of our beliefs are true fails to deal with the cumulative effect of adding beliefs which have variable reliability about different subjects. Plantinga asserted that the traditional theist believes being made in God's image includes a reflection of divine powers as a knower, but cognitive science finds human reasoning subject to biases and systematic error. Traditional theology is not shown to predict this varying reliability as well as science, and there is the theological problem of the omnipotent Creator producing such imperfection. They described how Plantinga set out various scenarios of belief affecting evolutionary success, but undercut the low probability he previously required when he suggested an "inscrutable" probability, and by ignoring availability of variants he fails to show that false beliefs will be equally adaptive as his claim of low probability assumes. Even if his claims of improbability were correct, that need not affect belief in evolution, and they considered it would be more sensible to accept that evolutionary processes sometimes have improbable outcomes. They assessed Plantinga's main argument—which asserts that since the reliability of evolutionary naturalism is low or of inscrutable value, those believing it should withhold assent from its reliability, and thus withhold assent from anything else they believe including evolutionary naturalism, which is therefore self-defeating—and found it unconvincing, having already disputed his argument that the reliability is low.