《论衡·卷二十·论死篇》
如果人死后，精神变成 五行之物 的话，就能害人，不变成 五行之物 ，就不能害人。
使人死，精神为五行之物乎，害人；不为乎，不能害人。
If after someone dies, their spirit becomes one of the five elements, then it can harm humans. If it doesn't become one of the five elements, then it can't harm humans.