《论衡·卷二十五·祭意篇》
山林、川谷、丘陵能生出云，产生风雨，出现怪物，都称为神。统治天下的帝王祭祀百神。
四坎坛，祭四方也。山林川谷丘陵能出云，为风雨，见怪物，皆曰神。有天下者祭百神。
Mountains, forests, rivers, valleys, hills can produce clouds, produce wind and rain, and produce monsters, are all called gods. The emperor who ruled the world worshipped the hundred gods.