"Poetry begins in trivial metaphors, pretty metaphors, "grace" metaphors, and goes on to the profoundest thinking that we have. Poetry provides the one permissible way of saying one thing and meaning another. People say, "Why don’t you say what you mean?" We never do that, do we, being all of us too much poets. We like to talk in parables and in hints and in indirections - whether from diffidence or some other instinct."

Source: Education by Poetry. Robert Frost's speech at Amherst College in Massachusetts, www.en.utexas.edu. February 1931.