In his famous Preface to Lyrical Ballads (1800/1802), Wordsworth propounded his theory of Poetic Diction — arguing that poetry should use the real language of ordinary men, not the artificial, elevated 'poetic diction' of 18th-century verse. He defined poetry as 'the spontaneous overflow of powerful feelings' recollected in tranquility. The distinction between Fancy and Imagination was elaborated by Coleridge in Biographia Literaria.