Quote #1 Answer:
Physician, cultural critic, and (apparently atheist or agnostic) Theodore Dalrymple.
Quote #2 Answer:
Philosopher of Science, Agnostic, and frequent critic of Creationism and Intelligent Design, Michael Ruse
(HT: Paul Copan)
. . .
I found both of these quotes -- resulting from reflection on the human condition and relating it back to the Christian doctrine of human sinfulness -- fascinating in part because they come from people who do not subscribe to, or even reject, Christianity.
Dalrymple is particularly interesting because of his experience as a prison doctor and physician to the poor in England. He has seen it all, and had many one-on-one dialogues with people in a variety of circumstances, from victims to perpetrators, to self-victimizing. This base of raw exposure to humanity forms the soil for his views on human nature, on the disintegration of culture, and so on, which find expression in City Journal and other publications. His essay, "The Frivolity of Evil," (the source of the quote) should be required reading for teenage girls, if not teenage boys, who are rapidly approaching sexual maturity. In a more recent essay, "What the New Atheists Don't See," he seems to admit to being an atheist or agnostic himself, though he is acutely critical of the "new atheists" (Harris, Hitchens, and Dennett) and is sympathetic to religion for its contribution to Western Society.