Likelihoods

The Discrimination Question

A likelihood asks: if this hypothesis were true, how expected would this evidence be? Evidence is powerful when it discriminates among hypotheses. If the evidence is equally expected whether a claim is true or false, it should not move confidence much.

This is a central reason vividness misleads. Vivid evidence can feel important while failing to distinguish between competing explanations.

Comparative Thinking

Likelihoods are comparative. A symptom, document, behavior, experiment, or testimony must be compared across live possibilities. How likely is it under H1? Under H2? Under mundane alternatives? Under error, fraud, noise, coincidence, or selection effects?

Good reasoning often improves simply by adding the missing comparison class.

Likelihoods in Credencing

Likelihood reasoning improves Deep Rationality because it sharpens the path from E0 to EP. It helps the agent perceive what the evidence actually supports rather than merely noticing that something happened.

Adjacent References

These are starting points rather than exhaustive citations. They connect this page to nearby work in probability, calibration, cognitive bias, and social epistemology.

• |Thomas Bayes, "An Essay towards solving a Problem in the Doctrine of Chances" (1763).
• |E. T. Jaynes, Probability Theory: The Logic of Science (2003).