Alvin Plantinga's Warranted Christian Belief (2000), the third volume of his epistemology trilogy (preceded by Warrant: The Current Debate and Warrant and Proper Function, both 1993), is the most important work in the epistemology of religious belief written in the twentieth century. It argues that Christian belief - specifically, belief in the personal, providential God of the Bible, in the incarnation of Christ, in the atonement, and in the resurrection - can be epistemically warranted (the property that makes true belief into knowledge) even without philosophical argument or evidence. Drawing on Calvin's concept of the sensus divinitatis and on a Reformed account of the internal witness of the Holy Spirit (testimonium Spiritus Sancti internum), Plantinga develops what he calls the 'Aquinas/Calvin model' of how belief in the God of Scripture can be 'properly basic' - rational, warranted, and justified without being inferred from other beliefs.
The Thinker and His Work
Alvin Plantinga (born 1932), emeritus professor at the University of Notre Dame, is the most influential philosopher of religion in the analytic tradition. His earlier work on the ontological argument (The Ontological Argument, 1965) and on free will and the problem of evil (God, Freedom, and Evil, 1974) established him as a major philosopher; his modal ontological argument was regarded as technically valid even by many who rejected its premises. God and Other Minds (1967) argued that the evidence for the existence of other minds was exactly parallel to the evidence for the existence of God - making the rationality of theism on a par with beliefs universally regarded as rational. Warranted Christian Belief completed this project by providing a comprehensive epistemological framework within which distinctively Christian (not merely theistic) belief could be defended as rational.
Biblical Texts Engaged
Romans 1:19-20 - 'For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made' - is the Pauline testimony to the sensus divinitatis that Plantinga takes as his starting point. Paul's claim that all human beings have direct cognitive access to knowledge of God through the created world - not through argument from the created world but through the created world directly - is, for Plantinga, a phenomenological description of the sensus divinitatis: the cognitive faculty that, when functioning properly in the right conditions, produces immediate, non-inferential belief in God.
John 17:3 - 'And this is eternal life, that they know you, the only true God, and Jesus Christ whom you have sent' - grounds the specifically Christian content of the warranted belief Plantinga describes. The sensus divinitatis produces belief in God; the extended Aquinas/Calvin model describes how the internal witness of the Holy Spirit produces warranted belief in specifically Christian claims - the truths of the Gospel as presented in Scripture. Knowledge of God, in the biblical sense, is personal and salvific, not merely theoretical.
Core Argument
Plantinga's epistemological framework distinguishes between being rational (not violating any epistemic duties), being justified (having the right to hold a belief), and being warranted (having the property that converts true belief into knowledge). He argues that warrant is a matter of proper function: a belief is warranted if it is produced by cognitive faculties functioning properly in the right environment, according to a design plan aimed at truth. The interesting question for Christian belief is not whether it is internally rational (believers are not violating any epistemic duties in holding it) but whether it has warrant.
The 'de jure objection' to Christian belief - the claim that Christian belief is irrational, unwarranted, or epistemically improper regardless of whether Christianity is true - is Plantinga's target. His argument is that the de jure objection cannot be sustained independently of the de facto objection (whether Christianity is actually true). If the Aquinas/Calvin model is true - if God exists and has created human beings with a sensus divinitatis and has sent the Holy Spirit to produce belief in the Gospel - then Christian belief is warranted in exactly the way the model describes. The epistemic question depends on the theological question; one cannot establish that Christian belief is unwarranted without first establishing that Christianity is false.
Intellectual Context
Plantinga developed Warranted Christian Belief in the context of 'Reformed epistemology' - a movement he had initiated with his paper 'Is Belief in God Rational?' (1981) and developed with Nicholas Wolterstorff in Faith and Rationality (1983). Reformed epistemology challenged the 'evidentialist objection' to religious belief (the claim that belief is rational only if based on sufficient evidence) by arguing that the evidentialist principle is itself unwarranted - that there are many properly basic beliefs (beliefs about other minds, the past, the external world) that are rational without being based on argument.
Reception and Critique
John Schellenberg's Divine Hiddenness and Human Reason (1993) offers the most sustained response from within analytic philosophy: if the sensus divinitatis were functioning as Plantinga describes, why do so many sincere, open-minded people fail to believe in God? The 'divine hiddenness' objection argues that the non-belief of sincere seekers is incompatible with the existence of a perfectly loving God who desires relationship with all.
John Mackie argued in The Miracle of Theism (1982) that Plantinga's defense of basic belief was too permissive - by the same standards, any belief (in ghosts, in astrology, in any religious tradition whatsoever) could be declared properly basic. Plantinga's response was that proper basicality is established by the phenomenology of particular belief-forming processes, not by a general policy, and that the sensus divinitatis has a specific phenomenological character that distinguishes it from mere credulity.
Legacy
Plantinga's work transformed the epistemology of religious belief in analytic philosophy, making it intellectually respectable to hold distinctively Christian beliefs without apologetic argument. His arguments have been engaged at length by atheist philosophers (Mackie, Draper, Schellenberg, Sosa) and by sympathetic critics within Christian philosophy. The tradition of Reformed epistemology he founded continues to be productive in analytic philosophy of religion.
Key Passages
'Christian belief, if true, has warrant... The conclusion to be drawn, I think, is that the de jure question cannot be settled prior to and independently of the de facto question. The objector can't sensibly claim that Christian belief is unreasonable or unwarranted or not rationally justified, without engaging the de facto question.' (Warranted Christian Belief, ch. 6)
Contemporary Relevance
Plantinga's epistemology addresses the standard assumption that religious belief - unlike scientific belief - requires justification through public evidence and argument. His argument that the biblical teaching about the sensus divinitatis provides an epistemically respectable account of how direct, non-inferential belief in God can be warranted has implications for religious education, for the apologetics of interfaith dialogue, and for the self-understanding of religious communities. His insistence that the questions 'Is Christianity rational?' and 'Is Christianity true?' cannot be separated is one of the most philosophically important insights in contemporary philosophy of religion.