"This autobiographical reminiscing started more than ten years ago," wrote German-American philosopher Paul Arthur Schilpp at the age of ninety-five. "After my retirement in 1981," he continued, "I began dictating fragmentary memoirs off and on. Belatedly I was realizing how useful it might have been to have kept personal journals over the long span of my lifetime."

"But in years of wonderful vitality, which miraculously had continued into my eighties," Schilpp explains, "I was caught up with living life from moment to breathless moment. Rush there and lecture someplace. Rush home and...