The whole history of the thing called rhyme can be found between those two things: the simple pleasure of rhyming "diddle" to "fiddle," and the more sophisticated pleasure of rhyming "diddle" to "idyll." Now the fatal mistake about poetry, and more than half of the fatal mistake about humanity, consists in forgetting that we should have the first kind of pleasure as well as the second. It might be said that we should have the first pleasure as the basis of the second; or yet more truly, the first pleasure inside the second. The fatal metaphor of progress, which means leaving things behind us, has utterly obscured the real idea of growth, which means leaving things inside us.