The author argues that in the present discussion over the meaning of Vatican II, considered from the historical vantage point of 40 years, the council needs to be resituated as an event of the mid-20th century. Its break with the past, embodied in ruptures and reversals of long-standing Catholic mentalités, must be seen as a response to two world wars, the Holocaust, the Atomic Age, atheist communism, postwar existentialism, and the Cold War. Current debates about whether “anything happened” at Vatican II should consider that the new age inaugurated by the council was not merely possible; it was morally necessary.