But if you define rationality as either "obtaining beliefs that correspond to reality as closely as possible" or "achieving your values", it seems that the sighted man has been more successful. I guess "believing, and updating on evidence, so as to systematically improve the correspondence between your map and the territory" is better, since the blind man has less evidence. I think the question now, though, is when a person "has" a given piece of evidence. What if I fail to recognize that a certain fact is evidence for a certain hypothesis? What if I do recognize this, but don't have the time to apply Bayes' law?