Percy Bysshe Shelley, Mary Wollstonecraft Shelley (1840). “A defence of poetry. Essay on the literature, arts, and manners of the Athenians. Preface to the Banquet of Plato. The banquet”, p.40
"Young Poets". Edith Sitwell's lecture (1957); later published in "Mightier Than the Sword: The P.E.N. Hermon Ould Memorial Lectures, 1953-1961" (p. 56), 1964.