Although American by birth and heritage, James McNeill Whistler spent most of his life in western Europe, particularly in Paris and London, where he lived his life in a swirl of controversy over his art and his often self-aggrandizing behavior, which tainted his associations with fellow artists and the public. His guiding principle was ?art for art?s sake? meaning that the artist should only work to please himself. Whistler?s tonally disciplined palette distinguishes his painting from all other artists and provides his work with sophistication and elegance. He was a leader in the Aesthetic Movement and frequently wrote and lectured about his ideas on art and philosophy. Common themes were landscapes and portraits. Whistler often gave his works generalized titles, such as Arrangement in Grey and Black: No.1 , better known as Whistler?s Mother , in order to emphasize his belief in the importance of line over color, composition over content. Whistler also frequently titled his works using words such as symphonies, harmonies, compositions, and arrangements. Throughout his long and somewhat contentious professional life, Whistler steadily produced outstanding works of art held today in the world?s most prestigious museums.