From Wonderful Life: The Burgess Shale and the Nature of History, by Stephen Jay Gould
"Homo sapiens, I fear, is a 'thing so small' in a vast universe, a wildly improbable evolutionary event well within the realm of contingency. Make of such a conclusion what you will. Some find the prospect depressing. I have always regarded it as exhilarating, and a source of both freedom and consequent moral responsibility."
From Chapter IV, Woolcott's Vision and the Nature of History