In Greek mythology, hope was the one thing left inside Pandora’s jar after the evils escaped.
Hesiod’s Works and Days says that Pandora lifted the lid of the storage vessel, releasing the troubles that had previously been kept away from humans. Hope, called Elpis in Greek, remained inside because the lid was replaced before it could leave. The ending has generated extensive debate because the poem does not plainly explain whether hope is a comfort or another troubling force.
In later popular culture, the story is usually interpreted as saying that hope remained available to humanity after suffering entered the world. That optimistic reading is widespread, but scholars have noted that Hesiod’s presentation is more ambiguous and may not treat hope as unambiguously beneficial.
The common phrase “Pandora’s box” is also technically imprecise. Hesiod describes a pithos, or large jar, not a small box. “Box” became standard through later translation and retelling.