Samuel Taylor Coleridge (21 October 1772 - 25 July 1834) was an English poet, literary critic and philosopher who, with his friend William Wordsworth, was a founder of the Romantic Movement in England and a member of the Lake Poets. He wrote the poems The Rime of the Ancient Mariner and Kubla Khan, as well as the major prose work Biographia Literaria. His critical work, especially on Shakespeare, was highly influential, and he helped introduce German idealist philosophy to English-speaking culture. He coined many familiar words and phrases, including the celebrated suspension of disbelief. He was a major influence on Emerson, and American transcendentalism. Throughout his adult life, Coleridge suffered from crippling bouts of anxiety and depression; it has been speculated by some that he suffered from bipolar disorder, a condition not identified during his lifetime. Coleridge suffered from poor health that may have stemmed from a bout of rheumatic fever and other childhood illnesses. He was treated for these concerns with laudanum, which fostered a lifelong opium addiction.