In The Use of Poetry (1933), T. S. Eliot referred to the letters of John Keats (keets) as “the most notable and the most important ever written by any English poet,” primarily because “there is hardly one statement of Keats about poetry, which . . . will not be found to be true.” The letters also offer an important gloss on specific poems and have thus become important for understanding Keats. Besides many passing comments of brilliance, the central concept of the letters is “negative capability.” As defined by Keats, it is the capability to remain “in uncertainties, Mysteries, doubts, without any irritable reaching after fact & reason,” which implies a disinterestedness that permits even competing ideas full play to reach their potential. In his letters, Keats often carried an idea to its extreme with extraordinary intellectual flexibility; another day, its opposite will surface to be worked out, as all things “end in speculation.” The concept is also taken to include Keats’s understanding of the poetical character, or the ability to surrender one’s personal self to create characters and objects with independent life. Keats believed that the artist’s first responsibility was to create beauty, which implies that the artist’s personally held ideas and beliefs should be temporarily suspended or treated only partially so as to realize fully the work’s aesthetic potential. Through the use of sympathetic imagination, Keats attempted to become the thing he was creating, to intensely identify with its life, not to find his personal life reflected in it. The standard edition of Keats’s letters is The Letters of John Keats, 1814-1821 (2 volumes; 1958, Hyder Edward Rollins, editor). Text citations are to that edition.