hamartia
the fatal misjudgment
Today this word meansThe error of judgment that carries the hero to ruin.
Originally an archery word: "missing the mark."
It is what Aristotle named as the reason a tragic hero falls.
Oedipus pressing his inquiry into the truth to the very end is the standard example.
Worth noting
Often rendered "tragic flaw," but the Greek means not a moral defect so much as **a judgment gone wide of the mark**. The point is that the hero falls not from wickedness but from knowing wrongly.