John Keats (1795-1821) was an English Romantic poet whose prominence grew in the years following his untimely death at the age of 25. Despite the fact that he only wrote seriously for about six years, Keats remains among the most celebrated and influential writers in the history of English language. The quote below is from a letter he wrote in 1818.

"Poetry should be great and unobtrusive, a thing which enters into one's soul, and does not startle it or amaze it with itself, but with its subject."

(h/t WikiQuote)