Reformed Epistemology (RE) is roughly "the thesis that religious belief can be rational without arguments." 1 To a large extent RE is centered upon a rejection of the evidentialist objection to theism.Let the evidentialist objection be the thesis that one can only hold proposition p, namely that God exists, justifiably if and only if one supplies evidence E in support of p. Assuming one does not have E, it follows that one would be unjustified in upholding p. Advocates of RE, against to this objection, hold that belief in God can be justified without recourse to propositional evidence.Alvin Plantinga, RE's prime proponent, has argued on the basis of what he coins the Aquinas-Calvin (or A/C) model that theistic belief can be properly basic with respect to warrant.Plantinga's account of RE is a form of epistemic externalism. Externalism is regarded as simply the denial of internalism, which is roughly the thesis that "the justifying reason for a basic belief, or indeed for any belief, must somehow be cognitively available to the believer himself". 2 Externalists generally hold that although "there must in a sense be a reason why a basic belief is likely to be true, the person for whom such a belief is basic need not have any cognitive grasp of this reason." 3 In other words, a belief can result from "factors external to the consciousness of the believer: factors involving how that belief is caused, or how well it tracks the facts, or how reliably it is formed" and still be warranted. 4 Plantinga uses the term warrant to denote "that quantity, enough of which is what distinguishes knowledge from mere true belief". 5 He sets out to construct an account of warrant which is coined 'proper functionalism'. 6 He argues that a particular belief can have warrant if and only if it arises in the following way: 71. The belief is produced within a subject from cognitive faculties that are functioni ng properly, according to how they have been designed to operate. 8 2. Those cognitive faculties are functioning in an epistemic environment for which t hey were designed to function properly.3. The design plan of those cognitive faculties is such that they are aimed toward the acquisition of true belief. 4. The design plan of those cognitive faculties aims successfully at acquiring true beliefs. The design plan is a "good one" to the extent that there is a high probability that beliefs produced by such cognitive faculties will be true.