In 1773, Cowper experienced an attack of insanity, imagining not only that he was eternally condemned to hell, but that God was commanding him to make a sacrifice of his own life. Mary Unwin took care of him with great devotion, and after a year he began to recover. In 1779, after Newton had moved from Olney to London, Cowper started to write poetry again. Mary Unwin, wanting to keep Cowper's mind occupied, suggested that he write on the subject of "The Progress of Error." After writing a satire of this name, he wrote seven others. These poems were collected and published in 1782 under the title "Poems by William Cowper, of the Inner Temple, Esq."