I know many books that have bored their readers, but I know of none which has done real evil.
[Voltaire was wrong. This is not to take issue with Voltaire’s primary message of strong civil liberties in general or even free speech in particular.
Voltaire should have known of the tens or hundreds of thousands kill because some religious book said followers should kill, maim, or enslave non-believers. But he didn’t live at a time to have seen the hundreds of millions dead due, in large part, to Karl Marx‘s The Communist Manifesto. One can use the same arguments used in defense of the First Amendment in defense the Second Amendment. People that claim free speech doesn’t harm people like guns do only have to shown the millions and millions of dead in the Soviet Union, China, and other “people’s paradises”. And the sad part is that private weapons ownership would have prevented most of those deaths.