“"The bitterest sorrow that man can know is to aspire to do much and to achieve nothing"… so Herodotus relates that a Persian said to a Theban at a banquet (book ix., chap. xvi.). And it is true. With knowledge and desire we can embrace everything, or almost everything; with the will nothing, or almost nothing. And contemplation is not happiness — no! not if this contemplation implies impotence. And out of this collision between our knowledge and our power pity arises.”

The Things They Carried (1990), How to Tell a True War Story

Knowing Yourself: The True in the False (1996)

Source: The Importance of Being Earnest

"A Universe From Nothing" by Lawrence Krauss, AAI 2009 http://www.youtube.com/watch?v=7ImvlS8PLIo#t=23m40s (23:40-23:48)

The Need for Transcendence in the Postmodern World (1994)
Context: There appear to be no integrating forces, no unified meaning, no true inner understanding of phenomena in our experience of the world. Experts can explain anything in the objective world to us, yet we understand our own lives less and less. In short, we live in the postmodern world, where everything is possible and almost nothing is certain.

Source: Vittorio, The Vampire

Source: Extremely Loud and Incredibly Close (2005), p. 175