i hope I could stick something in his mouth though

when you talk about the history, it is not all about "opinion". it is about the "Fact". therefore, before you make any judgement or express your opinion, you have to do your homework, and learn enough "Basic" knowledge about history and then you can say something sensible. That is what i want to express.

but from this guy, i can not see any sign of that.
he likes making comments but does not have the basic knowledge of history to back himself up. that is what i do not like.

As you said that i have got no right to tell him shut up. I totally agree with this. but in the meantime, i also have to right to express my opinion and that is my right, is that correct?