Why did John Ruskin encourage artists to study nature closely?

John Ruskin encouraged artists to study nature closely because he viewed the natural world as a source of moral instruction and divine presence. In his influential work Modern Painters, Ruskin argued that painting should serve as a "noble and expressive language" capable of conveying profound truths rather than merely aesthetic pleasure.1

He believed that God spoke through physical "types" in the natural world, making the study of nature a form of morally instructive natural theology. Consequently, he urged young painters to approach nature with "singleness of heart," focusing entirely on penetrating its meaning and remembering its instruction without rejecting or selecting elements based on personal bias. By advocating for this "strenuously ethical" or "Theoretic" conception of art, Ruskin sought to align artistic practice with a deep, spiritual engagement with the environment, distinguishing his philosophy from the "art-for-art’s-sake" movement that emerged later in the 19th century.1