It matters not at all whether a modern play concerns itself with a grocer or a president if the intensity of the hero’s commitment to his course is less than the maximum possible. it matters not at all whether the hero falls from a great height or a small one, whether he is highly conscious or only dimly aware of what’s happening, whether his pride brings the fall or an unseen pattern written behind the clouds; if the intensity, the human passion to surpass his given bounds, the fanatic insistence upon his self-conceived role–if these are not present there can only be an outline of tragedy, but no living thing.
– Arthur Miller, from the introduction to his Collected Plays