John Dickson Carr

It__ all very well to have your eight suspects parading in their endless ring-around-the-rosebush outside the library. That__ fine. But give some sensible reason why they were there. If you must shower the room with bus tickets, provide a reason for that too. In other words, construct your story. Your present problem is not to explain the villainy of the guilty: it__ to explain the stupidity of the innocent.

Alan Campbell opened one eye.From somewhere in remote distances, muffled beyond sight or sound, his soul crawled back painfully, through subterranean corridors, up into his body again. Toward the last it moved to a cacophony of hammers and lights. Then he was awake.The first eye was bad enough. But, when he opened his second eye, such as rush of anguish flowed through his brain that he hastily closed them again.

The poor fool hadn't realized that if all mankind shares a folly or an illusion, and likes to share it even knowing what it is, then the illusion is much more valuable and fine a kind of thing than the ass who wants to upset it.