《论衡·卷二·命义篇》
承受的气形成坚强的生命，则气浓厚而身体坚强，身体坚强则寿命长，长就不会夭折；承受的气形成的生命软弱，则气稀薄而身体瘦弱，身体瘦弱则寿命短，短就会早死。
禀得坚强之性，则气渥厚而体坚强，坚强则寿命长，寿命长则不夭死。禀性软弱者，气少泊而性羸窳，羸窳则寿命短，短则蚤死。
People who carry the qi that forms a strong life are strong and healthy, and those who are strong and healthy will live a long life and will not die young; people who carry the qi that forms a weak life are thin and weak, and those who are thin and weak will live short lives and will die young.