W.K. Clifford once said that “it is wrong always and everywhere to believe something on insufficient evidence.” This is the heart of evidentialsim or theological rationalism. And it is precisely this view that Alvin Plantinga (AP) challenges with his reformed epistemology which develops a model of “warranted Christian belief”. He has two projects: one public and one Christian.

Public Project – Plantinga first distinguishes between de facto objections (aimed at showing the Christian faith to be false) and de jure objections (those aimed at undermining Christian belief even if true). Even though these can be distinguished, AP thinks argues that in the cases of Christian theistic belief there is no de jure objection independent of a de facto objection.

de jure to Theistic belief – According to the evidentialist, even if it is true that God exists, one is unjustified and irrational for believing this apart from evidence. Only beliefs that are properly basic (those that are self-evident or incorrigible) or inferred from properly basic beliefs do not require evidence. But AP wants to ask why belief in God can’t be a properly basic belief? For he sees no good reason to exclude this possibility. First, there are other things we believe without evidence that we seem entirely justified in doing so without appealing to evidence (i.e., the world is older than five minutes). Second, what evidence is there that only propositions that are self evident and incorrigible are properly basic? The theory fails its own test. So there is no reason to exclude the possibility of belief in God being Properly Basic.

AP argues that Christians are not only within their epistemic rights (Justification) in believing God exists, but also that they can know (Warranted) apart from evidence. The key to Plantinga’s Reformed Epistemology is warrant, “the property which turns mere true belief into knowledge when possessed in sufficient degree.” Justification, on AP’s view, is fairly easy to come by—it’s warrant that is important for knowledge. AP appropriates Calvin’s Sensus Divinitatis (or sense of the divine) in order describe the appropriate circumstances / faculty that form the belief that God exists in people. It is within this context that he offers his four criteria for warrant: 1) the cognitive faculties of the person are functioning properly 2) the cognitive environment is appropriate 3) the purpose of the epistemic faculty is aimed at producing true beliefs. 4) the objective probability of a beliefs being true is high. According to AP then, belief in God is properly basic with respect to warrant if God exists. But then the issue of God’s existence is no longer epistemic, but metaphysical or theological (enter arguments from Natural Theology). There is then no de jure objection to theistic belief.

de jure to Christianity – What about to specifically Christian Theism? AP expands his model to include the inner witness of the Holy Spirit. Due to humanity’s fall into sin, there have been disastrous cognitive and affective consequences. So if Christianity is true then belief in it is warranted in the same way mentioned above because belief is produced by the H.S.

Great Pumpkin Objections – the strongest objection to the public project is that it leads to radical relativism. For example, why could Linus’s belief in the Great Pumpkin not be properly basic for him? AP grants that Linus could be justified in his belief, but so what? He is still being lied to—so he possesses no warrant. Moreover, if Christian epistemologists can have belief in God be properly basic for them, then why not voodoo epistemologists? Again, AP will concede that they can within their epistemic rights (justified), but not warranted. So the Son of the Great Pumpkin Objection Fails. At most, all these objections show is that there is no de jure objection to theistic belief in general (e.g., Muslims). That will have to be settled dependent on how successful de facto arguments are against specific religious beliefs.

The Christian Project – while AP’s public project has been successful, his Christian project might need some modification. AP only offers thin evidence here, and his suggestion that if the Christian God exists, then he would want us to know him and would have provided a way for that to occur isn’t a statement that a Christian evidentialist would disagree with. So more insight from Scripture and experience is needed in order to explicate a Christian model of warranted Christian belief. Since the Sensus Divinitatis and the testimony of the H.S. are experientially indistinguishable, we ought to use the testimony of the H.S. (Rom. 8:16) because of Scripture. Also, the H.S. being described as a cognitive faculty outside of people that forms belief in them is off base. Rather, the H.S. is better seen as a form of testimony that provides the appropriate circumstances for a properly basic belief to be formed.

Overall, Alvin Plantinga’s Reformed Epistemology is a helpful (and many think successful) theory of explaining warranted Christian belief.

For more, see Warranted Christian Belief by Alvin Plantinga (Oxford University Press).