the structure of the best tragedy should not be simple but complex and one that represents incidents arousing fear and pity—for that is peculiar to this form of art.This reversal of fortune must be caused by the tragic hero's hamartia, which is often translated as either a character flaw, or as a mistake.The misfortune is brought about not by [general] vice or depravity, but by some [particular] error or frailty."The reversal is the inevitable but unforeseen result of some action taken by the hero.