Program / Course 19: Modern Challenges / Lesson 1.4
What you will learn
- Summarize the main Christian arguments against philosophical naturalism.
- Explain Plantinga’s argument about naturalism and the reliability of reason, and the replies to it.
- Describe how Catholic, Orthodox and Protestant thinkers differ in their approach.
- Distinguish a good argument from a conclusion that has been proved.
The big idea
Christian thinkers have answered naturalism and humanism in several ways. Some argue that the existence of the universe, its order, consciousness and moral truth are better explained by God. Some argue that naturalism undermines the reliability of reason itself. Others say that the demand for proof is the wrong demand, and that belief in God can be rational without it. None of these answers is accepted by every Christian, and none has convinced every critic. Each is best understood as an argument with strengths and open questions, not as a final proof.
Key terms
- Natural theology
- The attempt to reach knowledge of God by reason from the world, without relying on a revelation such as Scripture.
- Cumulative case
- An argument that gathers many pieces of evidence, none decisive alone, to show that one explanation is the best.
- Properly basic belief
- Plantinga’s term for a belief that can be rational without being based on other beliefs, as with memory or the existence of other minds.
- Evidentialism
- The view that a belief is rational only if supported by evidence.
- Fideism
- The view that faith stands on its own, apart from or against reason. Few Christian traditions teach it in a pure form.
- Apologetics
- The reasoned defense of the faith, from a Greek word meaning a defense. It is commanded in 1 Peter 3:15.
- Transcendental argument
- An argument that something must be true as a condition for some other thing that everyone accepts, such as knowledge or morality.
Background
Christians have defended their faith in argument since the apostles. Paul reasoned with philosophers in Athens (Acts 17). The second century writer Justin Martyr and the third century writer Origen answered pagan critics. Augustine, Anselm and Aquinas built arguments for God’s existence. In the eighteenth century the Anglican bishop Joseph Butler and later William Paley argued from nature and probability. These arguments are often called classical apologetics, and they are studied in the courses on arguments for God.
In the twentieth century Christian philosophy revived. C. S. Lewis made a popular case from morality and desire. Alvin Plantinga, Richard Swinburne, William Lane Craig and others, working in analytic philosophy, defended a range of arguments, and Plantinga also argued that belief in God does not need such arguments to be rational. At the same time, Catholic and Orthodox thinkers such as Etienne Gilson, Edith Stein and David Bentley Hart developed responses rooted in the older metaphysics of being.
Step-by-step explanation
Step 1: Arguments from the world
Cosmological arguments ask why there is something rather than nothing. If the universe exists, what explains that it exists at all? Aquinas offered the argument in several forms. Contemporary versions claim that a necessary being, which cannot fail to exist, is the best explanation. Naturalists reply that the universe itself might be a brute fact, needing no explanation, or that the question may be badly formed.
Teleological arguments (from design) point to the order of nature and to the fine-tuning of physical constants for life. Critics reply that multiverse theories or an unknown deeper law could account for it, or that the apparent tuning is a selection effect. These arguments are discussed in the courses on arguments for God and need not be repeated here. The point is that they are arguments, with real objections.
Step 2: Arguments from mind and morality
Lewis argued that all people feel the pull of right and wrong, and that this moral law is not just a habit or a feeling. If moral truths are real, he reasoned, they point to a mind behind the world. Moral arguments of this kind have many forms and many critics. Some atheist philosophers hold that moral facts exist without God, a position called moral realism, and accept the objectivity but not the theistic explanation.
A related argument concerns reason itself. Plantinga argues that if human beings are products of unguided evolution, there is reason to doubt that human faculties aim at truth, since natural selection rewards survival and not true belief. If so, he concludes, naturalism undermines itself. Naturalist replies are that survival usually does favor true beliefs about the environment, and that the argument depends on a contested estimate of probabilities. The debate is active.
Step 3: Reformed epistemology
A different reply asks whether the demand for proof is the right standard. Plantinga and others argue that many of the most sure beliefs, such as that the past is real or that other people have minds, cannot be proved from simpler beliefs. They are held rightly all the same. Belief in God, they say, may be like these, a natural conviction in the right conditions, which does not need argument to be rational.
Critics say that this makes faith too easy to defend, since almost any belief could claim to be basic. Plantinga replies that a belief can be tested for coherence and can be defeated by evidence, so it is not immune. This approach was influential in Protestant circles and is still debated.
Step 4: Where traditions differ
Catholics have formally taught that human reason can know God’s existence (Vatican I). Many Protestants, following Calvin, believe in a natural sense of the divine but stress that sin darkens it, and some, following Barth, distrust natural theology. Orthodox thinkers often prefer experience and worship to proof, while still using philosophical argument when needed.
On all sides, many Christians add that arguments are not the whole of faith. Pascal wrote that the heart has its reasons, and Augustine described a restless heart that finds rest in God.
- Is this an argument for God, or an argument against a specific form of naturalism?
- What is the strongest objection to it, and has it been answered?
- If the argument works, how far does it go: to a creator, to a mind, or to the Christian God?
- Does the argument fit the way I actually came to believe or doubt?
- Would I accept an argument of the same form if it supported a conclusion I disliked?
- What does the argument leave unexplained?
Examples
A cumulative case
A student lists five facts: the universe exists, it is ordered, it has produced minds, morality seems real, and many people report encounters with God. No one fact proves God. She argues that together they are better explained by God than by chance. A skeptical friend says they are better explained by natural causes. They agree on the facts and disagree on the weighing. (A constructed example.)
A basic belief
A man says he cannot prove that the world was not created five minutes ago with false memories. He knows it anyway. He says he knows God in a similar way, from long experience of prayer, and he does not claim that his argument would persuade a stranger. (A constructed example of Reformed epistemology.)
Different perspectives
Catholic
Catholic teaching, from Vatican I and the Catechism, holds that God can be known with certainty by the natural light of human reason from created things. Catholics usually prize Aquinas’s five ways and the harmony of faith and reason. They also teach that faith is a gift of grace, so that proofs prepare the way without producing faith by themselves.
Orthodox
Orthodox theologians often stress that God is beyond concepts and is known by experience. Vladimir Lossky wrote that the way of knowing God is partly apophatic, which means that it proceeds by saying what God is not. Arguments may remove obstacles, but they cannot replace participation in the life of the church. Hart nevertheless gives a sustained philosophical argument from the experience of being and consciousness.
Protestant
Protestants range from those who build arguments, such as Swinburne and Craig, to those who think that the Holy Spirit’s inward testimony is the ground of faith, as Calvin taught. Plantinga’s approach lies between the two. Barth and his followers doubted that natural theology could succeed without Christ.
Secular and scholarly views
Many philosophers reply that arguments for God fail on their own terms, or that they establish at most a vague first cause. They say that the Christian side cannot claim a settled victory. Others, including some atheists, admit that arguments such as the cosmological and moral arguments raise real puzzles that naturalism has not fully answered.
Why it matters
A Christian who thinks arguments prove everything will be shaken at the first good objection. One who thinks arguments are useless will have nothing to say to an honest questioner. The calm position is to treat arguments as contributions to a larger case, to admit their limits, and to remember that faith is more than a conclusion.
Common misunderstandings
Misunderstanding: Christianity can be proved like a theorem.
Correction: Most Christian philosophers argue that their case is reasonable and better than rivals, not that it has the certainty of mathematics. Faith also involves trust and commitment.
Misunderstanding: Arguments for God are all bad.
Correction: Several are taken seriously by philosophers who do not share the faith. A fair statement is that they are contested, not that they are refuted.
Misunderstanding: Plantinga says that faith needs no reasons.
Correction: He says belief in God can be rational without proof from other beliefs. He also gives arguments and accepts that beliefs can be defeated by evidence.
Misunderstanding: The Christian traditions agree on how to defend the faith.
Correction: They differ on the weight of natural theology, the role of experience and the effects of sin on reason.
Knowledge check
What is Plantinga’s argument that naturalism undermines itself?
He argues that if human minds arose by unguided natural selection, which rewards survival and not truth, there is little reason to trust that human reasoning is reliable. That includes the reasoning that led to naturalism. Critics reply that survival usually depends on accurate beliefs, so the probability is higher than he allows. The argument is still discussed.
What does it mean to say a belief is properly basic?
It means the belief can be rational without being derived from other beliefs. Memory, perception and the existence of other minds are common examples. Plantinga holds that belief in God can be in the same category under the right conditions. Critics worry that this makes any belief easy to defend, and he replies that basic beliefs can still be challenged.
How do traditions differ in their use of natural theology?
Catholic teaching holds that reason can know God’s existence and values the arguments of Aquinas. Many Protestants stress the inward witness of the Spirit and, following Barth, some doubt natural theology. Orthodox writers stress experience, worship and apophatic knowing, though they also use argument. All agree that faith is more than reasoning.
Why should a Christian say what remains open?
Because honesty requires it, and because claims that outrun the evidence give critics an easy target. Scripture asks believers to give a reason for their hope with gentleness and respect (1 Peter 3:15). Admitting where an argument ends is consistent with that, and often makes the rest of the case more credible.
Think it through
- Which argument in this lesson do you find most convincing, and which least?
- What reasons do you have for belief that are not arguments?
- How would you respond to someone who says faith requires no reasons at all?
- What would it mean to give an answer with gentleness and respect to an honest skeptic?
Independent assignment
One argument, one objection
In your notebook, choose one argument from this lesson. Write 400 to 600 words that state it as its defenders would, then state the strongest objection as its holders would, and then say honestly whether the reply is sufficient. End with one sentence saying what you still do not know. Do not send it.
Further study
- Alvin Plantinga, Warranted Christian Belief Read selectively for reformed epistemology and the evolutionary argument.
- Richard Swinburne, The Existence of God Read selectively for the cumulative case.
- William Lane Craig, Reasonable Faith: Christian Truth and Apologetics Read for a leading evangelical apologist’s approach.
- C. S. Lewis, Mere Christianity Read book one on the moral law.
- Stanford Encyclopedia of Philosophy, Moral Arguments for the Existence of God Read for versions of the moral argument and objections.
- 1 Peter 3:15 Be ready to give a reason for the hope that is in you, with meekness and fear.
- Acts 17:22 Paul speaks on Mars’ hill.