--Why are we fighting them? ...

--Why are we fighting them? --They're mad. We're sane. --How do we know? --That we're sane? --Yes. --Am I sane? --To all appearances. --And you, do you consider yourself sane? --I do. --Well, there you have it. --But don't they also consider themselves sane? --I think they know. Deep down. That they're not sane. --How must that make them feel? --Terrible, I should think. They must fight ever more fiercely, in order to deny what they know to be true. That they are not sane.
 Donald Barthelme

Quotes from the same author

My mother studied English and drama at the University of Pennsylvania, where my father studied architecture. She was a great influence in all sorts of ways, a wicked wit.
 Donald Barthelme
Now it is necessary to court her, and win her, and put on this clean dressing gown, and cut my various nails, and drink something that will kill the millions of germs in my mouth, and say something flattering, and be witty and bonny, and hale and kinky, all just to ease this wrinkle in the groin. It seems a high price.
 Donald Barthelme
Now, here is the point about the self: it is insatiable. It is always, always hankering. It is what you might call rapacious to a fault. The great flaming mouth to the thing is never in this world going to be stuff full.
 Donald Barthelme
I don't think you can talk about progress in art - movement, but not progress. You can speak of a point on a line for the purpose of locating things, but it's a horizontal line, not a vertical one.
 Donald Barthelme
Yes, success is everything. Failure is more common. Most achieve a sort of middling thing, but fortunately one's situation is always blurred, you never know absolutely quite where you are.
 Donald Barthelme