Poetry contains philosophy as the soul contains reason.
(Victor Hugo (1802-1885), French poet, novelist, playwright, essayist. Trans. by Lorenzo O'Rourke. "Thoughts," Postscriptum de ma vie, in Victor Hugo's Intellectual Autobiography, Funk and Wagnalls (1907).)
(Robert Frost (1874-1963), U.S. poet. Quoted in Robert Frost: a Backward Look, ch. 1, Louis Untermeyer (1964).
Samuel Taylor Coleridge wrote, in Biographia Literaria (1817), ch. 22: "In poetry, in which every line, every phrase, may pass the ordeal of deliberation and deliberate choice, it is possible, and barely possible, to attain that ultimatum which I have ventured to propose as the infallible test of a blameless style; namely: its untranslatableness in words of the same language without injury to the meaning.")
(Henry David Thoreau (1817-1862), U.S. philosopher, author, naturalist. A Week on the Concord and Merrimack Rivers (1849), in The Writings of Henry David Thoreau, vol. 1, p. 350, Houghton Mifflin (1906).)
As civilization advances, poetry almost necessarily declines.
(Thomas Babington Macaulay (1800-1859), British historian, Whig politician. Edinburgh Review (Aug. 1825). Milton, Critical and Historical Essays (1843).
Macaulay went on to explain: "In proportion as men know more and think more, they look less at individuals and more at classes. They therefore make better theories and worse poems.")