作为符号动物的人类不断追求更有效的交流手段和更完美的符号。这种追求在语言中体现为一种“普天同文”的理想。本文从完美符号的理论构想解读入手，结合传播效用分析，得出了这种理想的现实悖论。连同图像语言在内的任何一种符号语言都无法对现有自然语言构成替代性关系，它们只是高度符号化的当代文明中涌现的又一组符号系统，而不是凌驾于语言之上的“元语言”。从某种意义上说，“普天同文”已经以多元化的方式实现。

Human pursuits better communication tool and more effective signs. For example, a common language all over the world would avoid much trouble in communication. But the reality is not optimistic. According to the logic of ideal symbol theory, any language could not replace the different natural language we are using now. In a sense, human has their common language in different ways.