The figure known for descending into the underworld in search of knowledge is Orpheus from Greek mythology. Orpheus, a legendary musician, sought to retrieve his beloved wife, Eurydice, from Hades after her untimely death. His journey signifies the lengths one might go for love and the pursuit of understanding the afterlife. Orpheus's descent reflects the human desire to challenge fate, revealing deep emotional connections to life, death, and the quest for ultimate truth across various mythologies beyond Greece.