I believe that it is difficult to kill an idea because ideas are invisible and contagious, and they move fast.
I believe that you can set your own ideas against ideas you dislike. That you should be free to argue, explain, clarify, debate, offend, insult, rage, mock, sing, dramatize, and deny.
I do not believe that burning, murdering, exploding people, smashing their heads with rocks (to let the bad ideas out), drowning them or even defeating them will work to contain ideas you do not like. Ideas spring up where you do not expect them, like weeds, and are as difficult to control.
I believe that repressing ideas spreads ideas.
Neil Gaiman, The View from the Cheap Seats