The founders of the United States well understood this and so freedom of speech, religion, and the press are incorporated into the Bill of Rights.
This post was prompted by this fragment from a recent Lumo post:
Pure science is studied because the human beings have an inherent desire to learn the truth.
As it happens, I would like to agree with the sentiment, but as I said in a comment on that post:
From where I sit it looks like most people are mainly interested in shoving their version of "the truth" down other peoples throats. That applies to Muslims, Christians, atheists, and some string theorists.
Dependable whack-a-mole that he is, Lumo promptly reinforced my point by deleting the comment.
So why is it that tyrants fear dissent? Because their rule is built on lies.
What I haven't quite figured out yet is why string theorists are so afraid of dissent.