In 1800, Coleridge visited a doctor to seek relief from chronic rheumatic pain. The doctor prescribed laudanum, the liquid form of opium. Laudanum was a common and effective painkiller that, unbeknownst to doctors, was extremely addictive. Coleridge developed a dependency on laudanum that would last for 16 years. In the 19th century, chemical addiction was not understood as a disease the way it is now. It was believed that people who couldn't break their habit out of sheer will were weak. Coleridge felt disgusted and ashamed by his disease. "I have prayed with drops of agony on my Brow, trembling not only before the Justice of my Maker, but even before the Mercy of my Redeemer. 'I gave thee so many Talents. What hast thou done with them'?" Coleridge wrote to a friend who admonished him for his drug use. "You bid me rouse myself—go, bid a man paralytic in both arms rub them briskly together, & that will cure him. Alas! (he would reply) that I cannot move my arms is my Complaint & my misery."17
Coleridge traveled to Malta and Italy for two years, hoping the climate would improve his health. When he returned in 1806, he and his wife separated. Coleridge moved to London, though he continued to support Sara financially. In 1808, he moved into William Wordsworth's household in the village of Grasmere. He lived there for two years, writing and lecturing sporadically. He moved out in 1810. Soon after, Coleridge learned that Wordsworth had cautioned a mutual friend of theirs against taking the high-maintenance Coleridge into his home, warning that Coleridge had "a derangement in his intellectual and moral constitution."18 Coleridge was devastated by the betrayal. The two friends reconciled two years later, but their friendship was never as strong as it once was.
Coleridge had all but stopped writing verse, having noted that "When a Man is unhappy, he writes damned bad Poetry."19 In 1815, at the peak of his misery, Coleridge wrote a series of first person essays collectively entitled Biographia Literaria. It is considered his finest work. The essays covered topics in literature and philosophy, illuminating his wide-ranging intellect. Despite his suffering, the essays' language was elegant and inspired. "The poet, described in ideal perfection, brings the whole soul of man into activity," he wrote, "with the subordination of its faculties to each other, according to their relative worth and dignity."20