Ruskin's influence on art, architecture, and social reform was very great. His concern with justice and human rights is surprisingly modern. The author describes Ruskin's symptoms in the last ten years of his life when he was psychotic. It is suggested that Ruskin's fascination with, and fear of, light spots on a dark background might account for his attacks on Whistler, the painter. Ruskin admitted his mental illness and attributed it to the deprivations of his childhood. He had unusual and difficult relationships with women and young girls. The author's attempt to apply a psychiatric diagnosis to Ruskin seems awkward and far-fetched. He acknowledges that creativity such as Ruskin's is beyond the scope of his paper.