The social contract.

"Doesn't it bother you, that we have no social contract?"

"My whole life is one big compromise. I tiptoed around everyone like they were made of china. I spent all my time analysing what the effect would be if I said something. And then there was you. You're a reality junkie. If I offered you a comforting lie, you'd smack me over the head with it. Let's not change that."

"Okay."

House Season 5 Episode 17 - "The Social Contract"