… is from page 348 of H.L. Mencken’s September 12, 1926, Chicago Tribune essay titled “Another Long-Awaited Book” as this essay is reprinted in A Second Mencken Chrestomathy  (1995):
The savage is preëminently his brother’s keeper. He knows precisely what his brother ought to do in every situation and is full of indignation when it is not done. But the civilized man has doubts….