Night is a kind of boundary. As a symbol of death, she is the boundary of a man s life, because the world sprang from darkness, she might be called a boundary to the universe, and of course, she demarcates a man s day. He feels he must accomplish his objective in one day. That daily sense of urgency is carried over into the Greek concept of a lifespan. That urgency, combined with a newfound sense of the futility of man s efforts when the end is inevitable, drives Achilles mad.
Night also bridges boundaries, specifically the boundary between life and death.
Darkness mimics Hades, and at night, the dead may visit the living. Just as the grieving Achilles finally drifts off to sleep on the beach of Ilion, Patroklos visits him in a dream. He begs Achilles to release him from his purgatory. Night is associated indirectly with Sleep and Dream, for without her they could not exist. Sleep and Dream, through Night, facilitate man s journey through life and into death.