“By physical liberty I mean the right to do anything which does not interfere with the happiness of another. By intellectual liberty I mean the right to think and the right to think wrong.”

Very good! I just wish that governments and citizens in general would remember this.

A great quote from one of my favorite free thinkers.

I think it is useless. What he should have said is "By intellectual liberty I mean the right to think wrongly and the right to teach others wrong things." In the Soviet Union it was never against the law to believe in capitalism. It was only illegal to teach a belief in capitalism.