The 19th-century theory that art, whether visual or literary, is self-sufficient and need have no moral or social purpose. The doctrine is most succinctly expressed in the phrase ‘l'art pour l'art’ (art for art's sake) attributed to the French philosopher Victor Cousin (1792–1867) in his lectures on Le Vrai, le beau et le bien (1818, published 1836). Wider dissemination came with the publication of Madamoiselle de Maupin (1835) by Thèophile Gautier who, in the preface, goes further than Cousin by suggesting that any moral purpose is injurious to art. Aestheticism flourished in England from the 1870s to the 1890s, its principal theorists being Walter Pater, in the conclusion to The Renaissance (1873), and Oscar Wilde. The latter's assertion, under cross-examination, that there was no such thing as an immoral book was probably one of the factors that led to his imprisonment and his subsequent disgrace signalled the movement's decline. The foremost practitioners in painting were Whistler and Albert Moore. The former's habit of giving his works musical titles (Nocturne in Black and Gold, 1877; Detroit, Inst. of Arts) is symbolic of the Aesthetic movement's desire to emulate music, the most abstract, and therefore purest, of the arts.