John Ruskin was a prominent English art critic, social thinker, and philanthropist of the 19th century. He is known for his writings on art and architecture, as well as his influence on the Pre-Raphaelite Brotherhood. Ruskin's work emphasized the importance of nature, craftsmanship, and moral values in art and society. He also advocated for social and economic reform, and his ideas had a significant impact on the Arts and Crafts movement. Ruskin's legacy continues to be influential in the fields of art criticism, cultural theory, and environmentalism.