"It is therefore highly illogical to speak of 'verifying' (3.8 [the Bernoulli urn equation]) by performing experiments with the urn; that would be like trying to verify a boy's love for his dog by performing experiments on the dog." - E.T. Jaynes, Probability Theory
A monthly thread for posting rationality-related quotes you've seen recently (or had stored in your quotesfile for ages).