Lewis Thomas, “Information,” The Lives of a Cell:
The solitary wasp, Sphex, nearing her time of eggs, travels aloft with a single theory about caterpillars. She is, in fact, a winged receptor for caterpillars. Finding one to match the hypothesis, she swoops, pins it, paralyzes it, carries it off, and descends to deposit it precisely in front of the door of the round burrow (which, obsessed by a different version of the same theory, she had prepared beforehand). She drops the beast, enters the burrow, inspects the interior for last-minute irregularities, then comes out to pull it in for the egg-laying. It has the orderly, stepwise look of a well-thought-out business. But if, while she is inside inspecting, you move the caterpillar a short distance, she has a less sensible second thought about the matter. She emerges, searches for a moment, finds it, drags it back to the original spot, drops it again, and runs inside to check the burrow again. If you move the caterpillar again, she will repeat the program, and you can keep her totally preoccupied for as long as you have the patience and the heart for it. It is a compulsive, essentially neurotic kind of behavior, as mindless as an Ionesco character, but the wasp cannot imagine any other way of doing the thing.
Thoreau, Journal, 13 February 1859:
Sometimes in our prosaic moods, life appears to us but a certain number more of days like those which we have lived, to be cheered not by more friends and friendship but probably fewer and less. As, perchance, we anticipate the end of this day before it is done, close the shutters, and with a cheerless resignation commence the barren evening whose fruitless end we clearly see, we despondingly think that all of life that is left is only this experience repeated a certain number of times. And so it would be, if it were not for the faculty of imagination.