Yossarian looked at him soberly and tried another approach. 'Is Orr crazy?'
'He sure is,' Doc Daneeka said.
'Can you ground him?'
'I sure can. But first he has to ask me to. That's part of the rule?…
'And then you can ground him?' ?Yossarian asked.
'No. Then I can't ground him.'
'You mean there's a catch?'
'Sure there's a catch,' Doc Daneeka replied. 'Catch-22. Anyone who wants to get out of combat duty isn't really crazy.'
Orr is crazy, and can be grounded, but if he asks to be grounded he is sane - and he can only be grounded if he asks. Joseph Heller complained that the phrase 'a Catch-22 situation' was often used by people who did not fully understand what it meant. Given the mental contortions of the catch, this is not surprising.
In Catch-22 everything is doubled. Yossarian flies over the bridge at Ferrara twice; his food is poisoned twice; there is a chapter devoted to 'The Soldier who Saw Everything Twice'; the chaplain has the sensation of having experienced everything twice; Yossarian can name two things to be miserable about for every one to be thankful for; all Yossarian can say to the dying Snowden is 'There, there', and all Snowden can say is 'I'm cold, I'm cold'; Yossarian overhears a woman repeatedly begging 'please don't, please don't'; and Major Major is actually Major Major Major Major.(more from Telegraph)
The mad pairing reaches its apotheosis in the catch itself. As the novel says: 'Yossarian saw it clearly in all its spinning reasonableness. There was an elliptical precision about its perfect pairs of parts that was graceful and shocking, like good modern art, and at times Yossarian wasn't quite sure that he saw it at all, just the way he was never quite sure about good modern art…'