Defense Laboratory / Is faith irrational?
1. The objection
“Faith means believing something without sufficient evidence. In every other part of life we know that is a mistake. No one would accept a medical treatment, a financial claim or a legal verdict on faith. Religious people say they have faith precisely when the evidence runs out, and they praise believing anyway. That is the opposite of how a rational person proceeds. If you want to know whether something is true, you ask for evidence and follow it. Faith is a refusal to do that.
2. Investigation
Assumptions
- That faith, as Christians use the word, means belief held against or without evidence.
- That rational belief always requires proof or evidence that the believer can state.
- That trust in a person, which is a large part of what the Bible calls faith, is the same kind of thing as belief in a scientific claim.
- That we have no good reasons for trusting anything else we cannot check for ourselves, such as history, other minds or the testimony of experts.
- That religious believers do not have, or do not offer, reasons for what they believe.
Evidence and historical claims
- What does Hebrews 11:1 say faith is, and how does the chapter go on to describe the faith of the people it names?
- What does the Greek word pistis, translated faith, mean in the New Testament, and how does it relate to trust and faithfulness as well as belief?
- How do Thomas Aquinas and the Catholic tradition distinguish faith from knowledge and from opinion, and what do they say about reasons that make belief credible?
- What did William Clifford argue in the nineteenth century about believing on insufficient evidence, and how did William James answer him?
- What do Luke 24 and 1 Corinthians 15:3-8 say about appeals to witnesses and evidence, and how do historians assess such claims?
- How do Jewish thinkers describe emunah, and how does it compare to Christian faith?
Philosophical and theological claims
- What is the difference between believing a proposition and trusting a person?
- Does rationality require that every belief be justified by evidence, or only that beliefs not be held against evidence?
- Can a belief be reasonable for one person, given that person’s experience and circumstances, and unreasonable for another?
Logical structure
- Premise 1: A rational belief is one held on sufficient evidence.
- Premise 2: Faith is belief held without sufficient evidence.
- Conclusion: Therefore faith is irrational.
- Test each premise. Ask whether Premise 2 describes faith as the traditions understand it, and whether Premise 1 can itself be met for all the beliefs a reasonable person holds.
3. Christian responses
Response A: Faith rests on reasons but goes beyond them (Catholic teaching)
The First Vatican Council (1870) taught that faith is a reasonable assent, supported by external signs such as miracles and prophecy (called motives of credibility), and that it is also a gift of grace. Pope John Paul II, in the encyclical Fides et Ratio (1998), described faith and reason as two wings by which the human spirit rises to the truth. Aquinas held that faith is a form of knowing by trust in a witness, and that its object, God, goes beyond what reason can fully grasp.
On this view, faith is not opposed to reason, and reason without faith is not complete. The tradition rejects both a faith that refuses reasons and a reason that refuses to consider revelation.
Response B: Faith is trust and participation, not a conclusion (Orthodox emphasis)
Orthodox theology tends to describe faith as trust in a person and as a way of knowing that involves the whole of a person, not only the reasoning mind. The tradition speaks of the nous, the faculty by which the heart perceives spiritual realities, and treats the intellect and the life of prayer as belonging together. Faith is not seen as a leap in the dark, but as a response to someone who has been met.
Orthodox writers do not despise argument. They hold that argument takes its place within a life of worship and cannot replace it.
Response C: Faith is rational, and some think it needs no outside proof (Protestant views)
Protestants differ. Some follow an evidential approach, arguing that the historical case for Jesus and the resurrection is strong enough to make Christian belief reasonable. Others, in the Reformed tradition, hold with Alvin Plantinga that belief in God can be rational without being inferred from other beliefs, as is true of belief in other minds, and that rationality means beliefs formed by faculties working as they ought. A third strand, associated with Soren Kierkegaard, emphasizes that the highest truths cannot be reached by proof alone and that faith involves a commitment that reason cannot secure.
Luther spoke sharply of reason at times when it set itself against the gospel, but he used it freely in ordinary life. Most Protestants today do not hold that faith contradicts reason.
Response D: Reasonable trust is not what the objection describes (Jewish and philosophical views)
In Jewish thought the word emunah is closer to faithfulness and steady trust than to belief in a proposition without evidence. Jewish philosophers such as Maimonides in the Middle Ages sought to show that revelation and reason agree, while others have emphasized covenant and practice over argument.
Many philosophers, whether or not they are religious, also point out that we rely on trust constantly. We accept what we cannot test ourselves, such as history and the findings of experts, and we act on commitments that outrun our evidence. The question, they say, is not whether to trust but whether a particular trust is well placed.
4. The strongest counterargument
The strongest reply to Responses A through D is that the analogy to ordinary trust only goes so far. We trust experts because we can check their record, because they can be tested and corrected, and because other experts would expose their errors. Religious claims are often about matters that cannot be tested in that way, and religious traditions disagree with each other, so that trust placed in one tradition has no clearer warrant than trust placed in another. Critics also observe that people often describe faith as a virtue precisely because it persists when the evidence seems to weigh against it, which looks like a willingness to hold a belief regardless of what comes.
The strongest reply to the objection is that it assumes a standard of evidence that most of our beliefs, including the belief that this standard is correct, cannot meet. Defenders also argue that the objection describes only one meaning of the word faith, and that in Scripture, in the councils and in the great theologians the word means trust in a person who has shown himself reliable, which can be reasoned about like any other trust. Whether the grounds for trusting God are in fact good enough remains the point at issue, and that is a question about evidence, not about the nature of faith.
5. Your independent defense
- Write the objection in one sentence in your own words.
- Write a definition of faith as you think the objector uses the word, and then a definition as Hebrews 11:1 and one theologian of your choice use it. Note where they differ.
- Read Hebrews 11:1-6 in the King James Version. Write three sentences on what the author says faith is, and what it is based on.
- List five things you believe without having checked them yourself. For each, write what reasons you have for trusting the source. Decide what this shows and what it does not.
- Read one statement from Clifford or a similar critic of belief on insufficient evidence, and one reply from a believer. Summarize each in a paragraph its author would accept as fair.
- Choose your own position and write 300 to 500 words defending it. State what you mean by faith, what reasons you give for your trust, and where you think your reasons run out.
- Write the strongest objection to your own position. Make it as strong as you can, then answer it.
- Write one sentence on what would change your mind.
- Keep this in your own notebook or document. Do not send it anywhere.