I think Dr. Zamenhof was right when he said language was the main source of conflict.
But I would expand it. Conflict do not arise mostly from people speaking different languages and not understanding themselves. It mostly arises when people think they speak the same language, when in fact they do not. That is the cause of so many conflicts.
There is an example I like to take. Here in France, the people from outside the suburbs thinks that the youth living there is dumb. But, from what I have heard, it mostly that people don't understand what this youth is saying. They use the same words, but the meaning behind it vary so much, that we could consider this language as more than one.
#zamenhof #suburbs #language #languagebarriers