Proven

Concepts that have proven useful in ordering things easily achieve such authority over us that we forget their earthly origins and accept them as unalterable givens.

Degeneracy follows every autocratic system of violence, for violence inevitably attracts moral inferiors. Time has proven that illustrious tyrants are succeeded by scoundrels.

If my theory of relativity is proven successful, Germany will claim me as a German and France will declare me a citizen of the world. Should my theory prove untrue, France will say that I am a German, and Germany will declare that I am a Jew.

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.