From Hesiod's Works and Days,
But [Pandora] took off the great lid of the jar with her hands and scattered all these and her thought caused sorrow and mischief to men. Only Hope remained there in an unbreakable home within under the rim of the great jar, and did not fly out at the door; for ere that, the lid of the jar stopped her, by the will of Aegis-holding Zeus who gathers the clouds. But the rest, countless plagues, wander amongst men; for earth is full of evils and the sea is full. Of themselves diseases come upon men continually by day and by night, bringing mischief to mortals silently; for wise Zeus took away speech from them.
Sometimes it would be nice to reopen the jar.