“It follows that before a theory can be considered true, it is virtually indispensable that there be perfect freedom to impugn it. Any limitation, even indirect and however remote, imposed on anyone choosing to contradict it is enough to cast suspicion upon it. Hence freedom to express one’s thought, even counter to the opinion of the majority or of all, even when it offends the sentiments of the few or of the many, even when it is generally reputed absurd or criminal, always proves favorable to the discovery of objective truth.”
