I think the parent is maybe referring to something else, that I also heard in a documentary: that all writing systems with a "reduced" alphabet descend from the same source.
I guess the japanese case is a counterexample to this, but the idea was, iirc, that writing systems appeared at different places, and followed this pattern:
* At first, people just draw representations of whatever they want to refer to.
* These evolve to symbols.
* Then, using the "rébus principle", you use the _sounds_ of each symbol to be able to represent things for which you had no symbols.
This is the step where, say, the chinese and mayan systems are.
* Then, and this is the "reduced" part I'm referring to: you simply forget the original meaning of your symbol, and only take it for a basic sound.
If I understand correctly, this happened when some people wanted to adapt hieroglyphs to their (spoken) language: they dropped the hieroglyph as symbolic representations, and only used them for their sound.
The documentary I watched seemed to imply that all alphabets with this property (symbols have no meaning) descend from this moment.
It does sound a bit much.
I may be totally misunderstanding it all, so any correction is more than welcome!
* At first, people just draw representations of whatever they want to refer to.
* These evolve to symbols.
* Then, using the "rébus principle", you use the _sounds_ of each symbol to be able to represent things for which you had no symbols. This is the step where, say, the chinese and mayan systems are.
* Then, and this is the "reduced" part I'm referring to: you simply forget the original meaning of your symbol, and only take it for a basic sound. If I understand correctly, this happened when some people wanted to adapt hieroglyphs to their (spoken) language: they dropped the hieroglyph as symbolic representations, and only used them for their sound. The documentary I watched seemed to imply that all alphabets with this property (symbols have no meaning) descend from this moment.
It does sound a bit much. I may be totally misunderstanding it all, so any correction is more than welcome!