Washing-Out Principle

Canonical definition

The Washing-Out Principle is the result that Individuals who begin from different Priors come to share a Posterior that concentrates on the true Hypothesis as Evidence accumulates, so that where a Belief began ceases to matter. It holds under four conditions: the true Hypothesis is in the Hypothesis Space with a Prior above zero; the Evidence is generated by the Referent rather than by the Beliefs under test; items of Evidence are independent of one another and of what other Individuals believe; and Evidence from the Referent goes on arriving in sufficient quantity. Where a condition fails, the Posterior still converges, but on what the process generating the Evidence supports, which need not be Truth. Explanation. Each condition is a separate way the guarantee fails, with its own signature. A missing Hypothesis leaves the Posterior on the best-fitting wrong one. Evidence generated by the Belief confirms whatever is held (Endogenous Feedback). Correlated Evidence counts one source many times. A Referent that does not make contact leaves nothing to wash the Prior out. Attribution of the source of a want is the case in which all four fail at once. Source Opacity removes the Evidence that would discriminate source, Confabulation generates the Evidence from the Belief under test, and social transmission correlates it across Individuals. The behavioural Evidence that could still discriminate source arrives only where conditions move one source and not the others, which ordinary life seldom arranges.