When the fact doesn't meet the theory then let go the theory.

He was very much a man of moods, possibly owing to what is styled the artistic temperment. I have never seen, myself, why the possession of artistic ability should be supposed to excuse a man from a decent exercise of self-control.

The supernatural is only the natural of which the laws are not yet understood.

Doctors can do almost anything nowadays, can't they, unless they kill you while they're trying to cure you.

With thought, all problems can be resolved.

Sometimes I feel sure he is as mad as a hatter and then, just as he is at his maddest, I find there is a method in his madness.

Hercule Poirot: I am an imbecile. I see only half of the picture. Miss Lemon: I don't even see that.