When you see things that others don’t yet perceive, sharing your vision requires finding a way to get others to re-create those things in their own heads. A mathematical definition serves this purpose. It provides detailed instructions allowing others, starting with things they are already able to see, to mentally construct those new things.

Chinese artistic theory did not ‘fail’ to invent perspective: it rejected as invalid a single fixed perspective, stressing instead the multiplicity of viewpoints from which an object or landscape might be viewed.