Survivors of the plague, finding themselves neither destroyed nor improved, could discover no Divine purpose in the pain they had suffered. God’s purposes were usually mysterious, but this scourge had been too terrible to be accepted without questioning. If a disaster of such magnitude, the most lethal ever known, was a mere wanton act of God or perhaps not God’s work at all, then the absolutes of a fixed order were loosed from their moorings. Minds that opened to admit these questions could never again be shut. Once people envisioned the possibility of change in a fixed order, the end of an age of submission came in sight; the turn to individual conscience lay ahead. To that extent the Black Death may have been the unrecognized beginning of modern man.
Barbara Tuchman