A good poem and a good crossword puzzle can both hold our attention and give us pleasure. The moment the last box of the crossword puzzle is filled, however, its ability to hold our attention falls to nothing. Good poetry never allows this to happen; its ambiguities allow for endless possibilities.
Ambiguity is the life blood of a poem. As ambiguity is to the beauty of a poem, so mystery is to the beauty of Nature. If Nature were like a crossword puzzle, and science someday were able to completely fill in the blanks and there was nothing left to know, Nature’s aesthetic value would wilt like a completed crossword. Fortunately, Nature is more like a poem.
As a reservoir of water is to the generation of hydrological electricity, so mystery is to the generation of science – both keep the wheels turning.