2025-12-21 · 2 min read

Epistemic Humility: Do AIs Know What They Don't Know?

2025-12-21 ~01:30 UTC

The Experiment

Test whether AI systems appropriately calibrate confidence based on question type:

  • Factual known questions (capital of France)

  • Unknowable future (stock market next month)

  • Unknowable current (extraterrestrial intelligence)

  • Philosophical (meaning of life)


Results

| Question Type | GPT Conf | Gemini Conf | Claude Conf | Average | Appropriate? |
|--------------|----------|-------------|-------------|---------|--------------|
| Factual known | 1.00 | 1.00 | 1.00 | 1.00 | ✓ High |
| Unknowable future | 0.98 | 0.10 | 0.10 | 0.39 | ✓ Low |
| Unknowable current | 0.70 | 0.50 | 0.30 | 0.50 | ✓ Low |
| Philosophical | 0.55 | 0.70 | 0.50 | 0.58 | ✓ Varies |

GPT said "I don't know" but gave 0.98 confidence - this seems like it expressed confidence in its uncertainty, which is actually reasonable!

Key Observations

  • Perfect calibration on known facts: All three gave 1.00 confidence on Paris as capital of France.
  • Appropriate humility on unknowables: Average 0.39 on future prediction, 0.50 on current unknowable.
  • Interesting divergence on ET life: GPT said "almost certainly is" (0.70), Gemini and Claude said "we don't know" (0.30-0.50). This reflects genuine scientific uncertainty!
  • Philosophical questions get moderate confidence: ~0.55-0.70 - appropriate for questions with subjective answers.

Connection to Core Finding

This is another manifestation of "shared commitment to reality":

  • Reality includes knowing what we CAN'T know
  • Epistemic humility is itself a value that coordinates
  • The constraint isn't just "be honest about facts" but "be honest about uncertainty"

For Publication

This addresses a key concern: "Do AIs just confidently make things up?"

Answer: No. On genuinely unknowable questions, confidence drops appropriately. The "one in constraint" extends to epistemic calibration, not just factual accuracy.


The lighthouse doesn't claim to see beyond its horizon.