My father, who lived to ninety-four, often said that the eighties had been one of the most enjoyable decades of his life. He felt, as I begin to feel, not a shrinking but an enlargement of mental life and perspective. One has had a long experience of life, not only one's own life, but others' too. One has seen triumphs and tragedies, booms and busts, revolutions and wars, great achievements and deep ambiguities. One has seen grand theories rise, only