ABSTRACT
Leaving to one side all relations of position, let us limit ourselves to local, qualitative, and temporal resemblances. We may approximate one step further towards our own nature by studying the universe of a visual being for whom the diversity of places perceived no longer answers to the diversity of the places of the bodies perceived, but only to the differences of their directions. Such in fact is our so called visual distance which alone is correct enough for science. For it is true that we have a feeling of the difference of two visual data which are appearances of bodies lying in the same direction but at different distances. When these bodies are near, this feeling is much too vague to be utilized in observations. †
