Beliefs require observations
To form accurate beliefs about something, you really do have to observe it. This can be viewed as a special case of the second law of thermodynamics, in fact, since "knowledge" is correlation of belief with reality, which is mutual information, which is a form of negentropy.
- The Second Law of Thermodynamics, and Engines of Cognition by Eliezer Yudkowsky
- The Parable of the Dagger by Eliezer Yudkowsky