This study aims to investigate how Keats’s “Negative Capability” affected Keats’s anxiety over his identity and shaped his concept of a poet-healer’s role. I try to focus on receptive sympathy ability, rather than the submission of the self and the extinction of identity, in the Negative Capability theory. Keats saw poetry as a potentially healing agent and a poet as a type of healer to humankind after he agonized over his own difficult problems and the sufferings of the world. He gave up the practice of medicine for poetry shortly after he gained licensure as an apothecary. However, he continued to see the poet and the medical worker as related. His medical experience helped to shape his concept of the poet’s role as a healer. Apollo the god embodied the hope of healing by sympathetic power in Hyperion. However, Keats couldn’t finish the poem because of the limited capacity of a god-hero to experience the suffering of humans. He was forced to find an alternative hero in the poet-healer of The Fall of Hyperion and expressed the role of a poet as a sage, a humanist, a physician to all men. Keats was able to reach deeper sympathy in uncertainty and extend the role of sympathy and healing into a poet as well as a physician through his private medical experience.