I think poetry is a quintessentially human non-literal device to express the nonlinearity and self-referentiality encountered as we leave the familiar shores of the inner edge of the Mind, which spans the at first seemingly all too solid but upon inspection increasingly tenuous physical phenomenal world, for the farther-away shores of Mind's outer edge, which spans the at first foamlike and misty but upon introspection increasingly clearer noumenal world, from which "words return unsuccessful, the mind baffled".