John Ruskin

Ruskin's great instruction was simply to look harder. Modern Painters defended Turner by describing real skies, clouds and water so exactly that readers went outside to check, and The Stones of Venice reads Gothic carving as evidence of the freedom of the masons who made it. His The Elements of Drawing, a practical manual for beginners, still teaches attention better than most art books. The prose can be overwhelming and his opinions were often extreme, so start with selections from Modern Painters and a sketchbook.