 Keats' contemporary, poet Percy Bysshe Shelley (1792–1822) invoked a similar image of the nightingale, writing in his "A Defence of Poetry" that "a poet is a nightingale who sits in darkness and sings to cheer its own solitude with sweet sounds; his auditors are as men entranced by the melody of an unseen musician, who feel that they are moved and softened, yet know not whence or why.