If we cannot define stupidity, at least we can trace most human misfortunes and weaknesses to it. Its manifestations are legion, its symptoms are endless.
Richard ArmourShakespeare, who never could think up a plot by himself, found this one [Macbeth] in Holinshed's Chronicles, changing it just enough so that no one would recognize the source. He didn't count on the resourcefulness of modern scholars, who have to discover things like this to become associate professors.
Richard Armour