The Biographia Literaria has long been recognised as one of the central prose texts of the Romantic period, both for its value as a piece of elevated prose writing and for the insights into poetry, criticism and the faculties of the mind that it offers. It seeks to reunify philosophical thought and aesthetic feeling in the belief that genuine knowledge emerges from only such a synthesis. Dr Wheeler's analysis proceeds from a number of points of view. The gradual growth of the Biographia Literaria is illuminated by notebooks and letters that show Coleridge wrestling with the work over a period of fifteen years. The aesthetic and metaphysical thought informing the Biographia is also discussed in order to elucidate the methods and purposes of the work, in which Coleridge's use of metaphor and irony constitutes both the structure and the point of engagement with the reader.