The Clairvoyant Case
A woman has a perfectly reliable clairvoyant faculty she doesn't know she has. She forms true beliefs through it but has no justification for trusting it. Does she know?
Laurence BonJour introduced this case in 1980 as a direct objection to reliabilist theories of knowledge. The case is designed to show that reliable belief-formation is not sufficient for knowledge or justification, because something about the believer's own perspective must also be in order.
BonJour, L. (1980). Externalist Theories of Empirical Knowledge. Midwest Studies in Philosophy, 5(1), 53–73.
The scenario
Maude has a clairvoyant faculty she knows nothing about. It reliably produces true beliefs about distant events. When the president is in New York, she forms the belief "the president is in New York." She is always right.
She has no evidence that she has this faculty. She has never tested it, verified it, or traced its outputs to any reliable source. She also has strong background reasons to think clairvoyance is impossible. By the lights of her own evidence, the belief has no justification at all.
But the belief is true, and it was produced by a perfectly reliable process.
The reliabilist answer and BonJour's objection
Reliabilism says that a belief counts as knowledge when it is produced by a reliable cognitive process. Maude's belief satisfies this condition. The process works. By reliabilist standards, she knows.
BonJour found this conclusion unacceptable. Maude, as he put it, is being epistemically irresponsible. She has grounds to distrust the belief, no grounds to trust it, and yet she holds it. From her own perspective, she is simply accepting a belief that appears from nowhere and contradicts her evidence. That she happens to be right seems like the wrong kind of luck to generate knowledge.
The case targets a deep feature of reliabilism: it is entirely externalist. The epistemic standing of a belief depends on facts outside the believer's perspective. Whether the process is reliable is a fact about the world, not about what the believer can access or reason about.
What the case argues
BonJour's point is that internalist requirements matter. Justification is not just about how a belief was caused. It is about whether the believer has access to reasons that support the belief from within their own perspective.
If Maude has no way to assess the source of her belief, she has no justification for holding it, regardless of how reliable the source actually is. Knowledge may require not just that you be connected to the truth, but that you have some grip on why you should believe you are.
The clairvoyant case remains one of the most-discussed objections to reliabilism, partly because it is so simple. It does not invoke skeptical scenarios or exotic metaphysics. It just asks whether being right, in a sufficiently reliable way, is enough.
Discussion questions
- Would you trust a doctor who always gave correct diagnoses but could not explain how they arrived at them?
- Is being reliably right enough for knowledge, or do you have to understand why you are right?
- Think of something you believe but cannot fully justify. Does that make it not knowledge?
Take it to the dinner table.
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