Dr. 'Doc' Daneeka: There's a CATCH

Yossarian: A catch?

Dr. 'Doc' Daneeka: Sure. Catch-22. Anyone who wants to get out of combat isn't really crazy, so I can't ground him.

Yossarian: Ok, let me see if I've got this straight. In order to be grounded, I've got to be crazy. And I must be crazy to keep flying. But if I ask to be grounded, that means I'm not crazy anymore, and I have to keep flying.

Dr. 'Doc' Daneeka: You got it, that's Catch-22.

Yossarian: Whoo... That's some catch, that Catch-22.

Dr. 'Doc' Daneeka: It's the best there is.