Reformed epistemology and the cumulative case

Rational without arguments

Many believers have never heard an argument for God's existence. Is their faith irrational? The American philosopher Alvin Plantinga, with Nicholas Wolterstorff, opened the road that answers no, and it is called Reformed epistemology. Much of what we believe is rational without being inferred from anything else: that other people have minds as we do, that we remember what we had for breakfast. No one proves these by argument first and believes them afterwards. Such beliefs are called basic, and a basic belief formed in the right circumstances is ‘properly basic’.

Belief in God, Plantinga argues, can be like this Alvin Plantinga, Warranted Christian Belief. Beholding the starry sky, sensing one's guilt, knowing oneself forgiven, a person comes to believe, without reasoning it out, that God made all this, or that God forgives them. So the psalmist, looking up, speaks straight to God:

When I behold Your heavens, the work of Your fingers, the moon and the stars, which You have set in place — what is man that You are mindful of him, or the son of man that You care for him?

Psalm 8:3-4

The root of this road is Calvin. As Faith and reason showed, Calvin taught that God has planted a sense of the divine in every heart, and that our certainty about Scripture comes from the witness of the Spirit. He calls that certainty "a conviction which asks not for reasons" and yet "a knowledge which accords with the highest reason" Calvin, Institutes 1.7.5. From these two teachings Plantinga argues that a belief produced by faculties God made, working as they should, has ‘warrant’. If Christianity is true, Christian belief is very likely warranted; so the question is not finally whether there are arguments but whether it is true.

One point needs care. ‘Without arguments’ does not mean ‘without grounds’. A basic belief arises from experience, and when it meets an objection it needs an answer. Plantinga himself valued many arguments for God, and answered the claim that God and evil cannot both exist with his free-will defence: God may have good reason to allow evil in a world of truly free creatures Alvin Plantinga, God, Freedom, and Evil. Reformed epistemology is not fideism, which bids us give up reason and simply believe. It defends the rationality of an ordinary believer's faith. That biblical faith is no leap in the dark is taken up in What is faith?

Plantinga raised the best-known objection himself, in a 1983 essay, and answered it Alvin Plantinga, Reason and Belief in God. If belief in God can be basic without argument, why not belief in the Great Pumpkin, for whom Linus waits every Halloween in the Peanuts comic strip? His answer: to say that some beliefs are properly basic is not to say that any belief is, just as the rationality of trusting memory does not make every fancy rational. A basic belief rests on the circumstances that give rise to it and on faculties made to aim at truth, and belief in the Great Pumpkin has no such ground. Human beings have a natural sense by which they perceive God; they have none for the Great Pumpkin.

Many clues together

The cumulative case walks a different road. It rests neither on one decisive proof nor on one immediate knowing, but gathers many kinds of evidence and argues that Christianity explains them all best: as a detective draws footprints, timing and motive together to point to one person, or as a court weighs witnesses who never met. The British philosopher Basil Mitchell argued that religious belief is justified in this way, as historians and judges choose between rival interpretations Basil Mitchell, The Justification of Religious Belief.

The clues are many: that there is a universe and that it began; an order of nature that seems finely set for life; the law of right and wrong that everyone knows; Jesus in history and the empty tomb; human longing and the experience of meeting God (Does God exist?). C. S. Lewis, in Mere Christianity, takes the moral law that all people know as a clue to the meaning of the universe C. S. Lewis, Mere Christianity, Book 1, and moves from there to the question of who Jesus is Mere Christianity 2.3. In a 1944 talk he likened Christianity to the sun, believed not only because it is seen but because by its light everything else is seen C. S. Lewis, Is Theology Poetry?. G. K. Chesterton wrote that the evidence for him lay not in this or that demonstration but in "an enormous accumulation of small but unanimous facts" G. K. Chesterton, Orthodoxy. Timothy Keller takes the doubters' common objections first, then sets out clues which are not proofs one by one, but which together carry weight Timothy Keller, The Reason for God.

The criticism of this road is that weak arguments do not add up to a strong one: ten leaking buckets, as the saying goes, hold no more water than one. The cumulative case replies that the picture fits only if each argument has no weight at all. If each clue has some weight and they arise independently, then when they point to one place the conclusion is far more likely than any one of them could make it. A court gives great weight to witnesses who never met yet agree, and a rope made of many thin strands is strong.

In conversation: the roads together

In real conversations Christians often draw on several roads at once. John Frame uses evidence within presuppositional apologetics; Timothy Keller asks doubters to examine the beliefs beneath their doubts, and also sets out his clues and the history of the resurrection. Paul too came to different people differently:

To the weak I became weak, to win the weak. I have become all things to all people so that by all possible means I might save some. I do all this for the sake of the gospel, so that I may share in its blessings.

1 Corinthians 9:22-23

John Wesley's note gives Paul's meaning: "Accommodating myself to all, so far as I could consistent with truth and sincerity" Wesley. The approaches differ; the gospel does not. One person asks about history, another about starting points. A believer may be ashamed that she knows no arguments, a friend may want to see the whole picture, and someone asking out of pain needs us beside them before any argument. Listen to the question first, then draw on what each road guards. Classical and evidential apologetics remind us that faith stands on public history; presuppositional apologetics, that God is Lord of our thinking; Reformed epistemology, that an ordinary believer's faith can be rational; the cumulative case, that we may ask what best explains the whole of life.

The five roads are not a ranking but many hands serving one gospel. The course's last lesson, Apologetics as conversation, returns to the conversation itself. The next lesson, The cosmological and design arguments, takes the arguments for God one by one.

Practice