They’s love, that’s one. And courage. You can’t see neither of them, but they’re real. And air, of course. That’s one of your most important examples. You wouldn’t be alive a minute if there wasn’t air, but nobody’s ever seen a single speck of it.” … “All I’m saying is there is a lot more to this old world than meets the eye.” … “And darkness. You can’t see it no more than you can see air, but when its all around you sure enough know it.” (Serena, 65-66)