Paul Graham, co-founder of Y Combinator, on his blog:

There are two reasons why we need to be able to discuss even "bad" ideas. The first is that any process for deciding which ideas to ban is bound to make mistakes. All the more so because no one intelligent wants to undertake that kind of work, so it ends up being done by the stupid.

I’m not sure I’m on 100% board with Graham’s “quadrants of conformism,” but the article is still a great read.