The properly basic beliefs argument holds that belief in God can be rational without requiring evidence or argumentation, as it belongs to a special class of beliefs that are justified non-inferentially. According to this view, just as perceptual beliefs ("I see a tree"), memory beliefs ("I had breakfast this morning"), and beliefs about other minds ("she is in pain") are typically accepted without argument, belief in God can similarly arise from direct religious experience or a sensus divinitatis. The argument challenges classical foundationalism's restrictive criteria for basic beliefs, proposing instead that a belief is properly basic if it arises from properly functioning cognitive faculties in appropriate circumstances, even if it cannot be proven through argument or reduced to self-evident truths.
This position emerged prominently through Alvin Plantinga's work in the 1980s, particularly in "Reason and Belief in God" (1983) and developed further in his Warranted Christian Belief (2000). While Plantinga is the primary architect, the view builds on Reformed theology, especially Calvin's notion of the sensus divinitatis. Nicholas Wolterstorff contributed significantly in Reason Within the Bounds of Religion (1976), and William Alston's Perceiving God (1991) developed parallel ideas about religious perception. The historical roots trace back to Thomas Reid's common sense philosophy and, more distantly, to Augustine's emphasis on divine illumination. Contemporary defenders include Michael Bergmann, Michael Rea, and Kelly James Clark.
Critics raise several objections. The "Great Pumpkin objection" (originally from Michael Martin) argues that if belief in God can be properly basic, then any belief could claim this status, including belief in the Great Pumpkin. Defenders respond that not just any belief meets the criteria—properly basic beliefs must arise from reliable cognitive faculties operating in appropriate circumstances. Philip Quinn argues that for educated adults aware of religious diversity, belief in God requires evidential support. Reformed epistemologists counter that awareness of disagreement doesn't automatically defeat proper basicality, just as disagreement about perceptual beliefs doesn't undermine their basic status. Some argue the position is fideistic or irrational; proponents reply that it expands rather than abandons rationality by recognizing multiple legitimate sources of justified belief.
This formulation differs from related positions in reformed epistemology. While Alvin Plantinga's Model encompasses the entire epistemological framework including the A/C model and extended A/C model, properly basic beliefs focuses specifically on the foundational claim about non-inferential justification. Unlike the Great Pumpkin Objection, which is a critique rather than a positive position, this formulation defends the coherence of taking theistic belief as properly basic. It also differs from Warrant and Proper Function, which provides the broader theory of knowledge underlying properly basic beliefs but extends beyond religious epistemology to general epistemic concerns.