By Mathew Goldstein
In his book God in the Age of Science? A critique of religious reason, Herman Philipse tackles a question at the core of philosophy of religion: Are there good reasons for thinking that some specific subset of religious beliefs makes sense and is true? In particular, is the defense of bare theism by philosopher Richard Swinburne, which relies on Bayesian estimates of probabilities, successful? This book is too academic, and too expensive, to become a best seller, but the overall argument is easy to follow and understand.
Philipse reaches three conclusions that support atheism. First, traditional notions of gods are self-contradictory and dependent on analogy and metaphor, therefore it is an ill-defined concept. Second, theism lacks predictive power concerning existing evidence, undermining the integrity of Bayesian arguments deployed in its defense. Furthermore, the truth of theism is improbable given the scientific background knowledge concerning the dependence of mental life on brain processes. Third, the empirical arguments against theism outweigh the arguments that support, so insofar as Bayesian cumulative case strategy does work we should conclude that atheism is more probable than theism.
Philipse categorizes arguments for theism according to which of three possible pairs of opposing strategic decisions are utilized. We start with deciding whether theism is a cognitive, and thus a factual, claim. If it is non-cognitive, an approach favored by people such as Wittgenstein, then it isn't asserting anything of substance that merits being taken seriously, so that is a self-defeating strategy for defending theism.
Having selected the cognitive option, we next need to decide whether or not reasons and evidences are needed to justify theism. Alvin Plantinga is cited as an example of someone who defends the notion that no further reasons are needed for (his particular) religious beliefs to be warranted. However, theism, like all other existence beliefs, is reasonable or warranted only when there are good positive reasons to justify the conclusion that the belief is true.
Having concluded that we need good positive reasons to justify theism, our final decision is selecting the methods that provide us with good positive reasons. Either we employ the same methods that we generally rely on when investigating a factual hypothesis of existence, or we don't. If we opt to employ different methods then a public and persuasive validation is lacking, resulting in a credibility problem for theism. The outcome for theism is just as bad when we turn to the reliable methods of skeptical empiricism which refute and disconfirm theism. Page 343 summarizes the conclusion in one sentence: "Either religious believers have not succeeded in providing a meaningful characterization of their god(s), or the existence of this god or these gods is improbable given our scientific and scholarly background knowledge."