“How do you prove we exist? Maybe we don't.”

“You don't need to prove the existence of aliens.That's unproductive, unless we make a bet on it.”

“How do we know that even the realest of realities wouldn't be subjective, in the final analysis? Nobody can prove his existence, can he?”

“Well, what I don't get is why do we exist? I don't mean how, but why.' I watched the fireflies of his thoughts orbit his head. He said, 'we exist because we exist. . .we could imagine all sorts of universes like this one, but this is the one that happened.”

“But you can't prove God exists. And isn't that what all science is ultimately about? Proving theories about the universe?""Provability is not truth, Caro. Godel's incompleteness theorem tells us that, if we didn't already know it intuitively, which we do.”

“We don't know how far the ripples of our decisions go. We kill one, and maybe save a thousand. That's the code of the Fraternity. That's what we believe in, and that's why we do it.”