Reformed epistemology is the philosophical position that the belief in God is justified on the basis that the belief in God is properly basic and, as such, does not need to be justified by the truth of any premises through a deductively valid argument. This argument has been advanced particularly strongly by the philosopher and apologist Alvin Plantinga.
The argument hinges on a very particular interpretation of the practical understanding of the justified true belief model of knowledge. Even thought, the argument goes, the belief can only be viewed as inferable (rather than provable) from other truths, the view is justified on the basis that there are some epistemological systems in which the belief in God properly basic, where it is reasonable to accept it as a premise absent other evidence. Plantinga invokes the existence of other minds as a potential analogue:
- Alvin Plantinga: If we are justified, without other premises, in accepting the existence of other minds, we may be similarly justified in accepting the existence of a God. The claim "I am justified in believing that other minds exist" can be found to be true without any other premises. This claim is an instantiated claim. If we are permitted to treat an instantiated claim as properly basic, then there is some epistemological system in which the claim "I am justified in believing that there is a God" is true.
- Moreover, because my access to objective knowledge of true propositions is limited, that the proposition is justified is the only reasonable qualifier for whether a belief constitutes knowledge.
There are two major moves in this argument; both are fundamentally Cartesian. The first is the move about whether or not the move to the existence of other minds is actually properly basic. The second is the move concerning pragmatic acceptance of propositions where we must hold some degree of skepticism, based on an inability to gain "objective knowledge" and whether or not that move is a good one.