many of the world's great re- ligions." The Old Testament authors rewarded men of virtue with long lives. The New Testament promises followers of Christ a hereafter: "He that believeth on me," said the Lord, according to Saint John, "hath ever- lasting life."
In the Eastern philosophy-religions, the path to eternal life may be rather less exalted. Chinese Tao- ists, for instance, aim to reach hsien (immortality) through an austere diet, various unusual sexual prac- tices...