This study, originally from 1964, is in effect a biographical study of one aspect of Keats' life of the imagination. It suggests why he became a poet, shows how his attitude to his poetry changed, how in Jungian terms he first met his 'shadow', rejected it, then came to accept it, and how this affected his poetry. An intimate relationship between his letters and the poems is shown, along with a fresh interpretation of Endymion and of aspects of the two versions of Hyperion, Lamia, The Eve of St Agnes, and the other great odes.