One of the central tasks of the philosophy of religion is to provide an answer to the question Is belief in God justified? In recent decades, there has been a radical change in the way that many Christian philosophers approach this question.
Most discussion of this question presupposes an evidentialism, according to which belief in God is justified only if the balance of evidence suggests that such belief is true. The task of philosophers of religion is then seen as weighing the arguments for God’s existence against the arguments against God’s existence and determining which are the stronger.
Reformed epistemologists reject this evidentialist assumption, affirming that belief in God can be rational even in the absence of evidence for God’s existence. Reformed epistemology is thus a reaction against both evidentialism and classical foundationalism.
Foundationalism is a theory about how our beliefs are justified (epistemic justification). Foundationalists hold that there are two types of epistemic justification: inferential and non-inferential.
A belief is inferentially justified if it is inferred from other justified beliefs. If I believe with justification that my watch is accurate, and that my watch reads noon, then I can believe with justification that it is noon. I can infer that it is noon from other justified beliefs that I possess.
It can‘t be that all beliefs are justified inferentially. My belief that it is noon may be justified because it can be inferred from other justified beliefs, but what is it that makes those other beliefs justified? If it is that they can be inferred from still further justified beliefs, then the question returns again: what makes those beliefs justified?
The only way of halting this regress is to admit that there are some beliefs that are non-inferentially justified, i.e. that are epistemically justified but not because they can be inferred from other justified beliefs. Such beliefs are called properly basic or foundational beliefs, because, if the foundationalist is correct, all of our justification is ultimately derived from such beliefs; such beliefs are the foundation of all of our belief systems.
According to classical foundationalism, in order to be properly basic a belief must be either incorrigible or self-evident. A belief is incorrigible if it cannot possibly be found to be in error; belief in one’s own existence is thus an incorrigible belief. Self-evident beliefs include simple truths of mathematics and logic, such as 1+1=2 and the principle of non-contradiction.
Reformed epistemologists have criticised classical foundationalism as holding too narrow a view concerning which beliefs can be properly basic. Beliefs can be cited, such as belief in the existence of the past, or of the external world, that are clearly justified but cannot be either inferentially or non-inferentially justified on classical foundationalism. The existence of the past and the external world, are neither incorrigible nor self-evident, and cannot be inferred from beliefs that are incorrigible or self-evident. On classical foundationalism, then, belief in them cannot be justified.
Reformed epistemologists call for a more liberal view of proper basicality, and assert that belief in God can be properly basic. They therefore insist that it is improper to assume that belief in God is irrational unless evidence for God’s existence can be presented.