Perhaps, John Keats answers this question himself with his famous lines from "Ode to a Grecian Urn,"
A thing of beauty is a joy forever.
Beauty is truth, truth beauty.
This poetical character, which is the capability of subsuming one's personal self to the art, is what imbues objects with independent life. Keats held that the artist's personal ideas and beliefs should be suspended in order for the aesthetic potential of the work can be attained. And, in this act of suspension of the self into the art, Keats has found in this "vale of soul-making" the potential of attaining identity. Therefore, by immersing himself in his art in which he can experience beauty and truth, the physical pain of the body is transcended. This joy of beauty given to the mind and soul thus alleviates physical pain.