Say it were implemented in this world and you could say anything you like (written, spoken, signed whatever) to anyone who can hear/read/see it. What kind of problems could that create and are there any ways to resolve them without limiting that absolute free speech?
Could it even create unsolvable logical errors? E.g an omnipotent god can’t create a stone too heavy for itself to lift. Maybe there are similar things with absolute free speech.
You are right, it needs some kind of common understanding about what is hurtful. Or a way of resolving such conflicts.
I think the lack of such a common understanding is very new (we live in an overly individualistic time) and didn’t exist at that time when he said that.