It wouldn't be the opposite of freedom (that would be suppression), but definitely a limit to the freedom we currently have in certain regards. However, we already have formal and informal rules that restrict the actions of people and forces them to follow specific practices, so it wouldn't be entirely new. In fact it would probably improve the situations at both extremes: on the one hand some taboos would be revoked (as that's also a way to avoid discussion), and you could exclude crazy and confused people who don't partake in any actual discourse.

I didn't say at all people should be open to my particular arguments, but to arguments in general.

> I didn't say at all people should be open to my particular arguments, but to arguments in general.

If it's arguments in general,

* you can't hang up on salesmen,

* you can't kick 911 conspirators off your unrelated forum,

* you can't remove most trolls,

* you can't ban homeopathy threads from /r/science,

* etc.

In general, you lose the ability to moderate conversations in spaces you own, or decide what you spend your time doing. This is, to be honest, a pretty extreme idea if taken literally.

Or you could deem salesmen, 911 conspirators, trolls and homeopathy proponents as "crazy and confused", but who decides that? How is that any more unwanted than posting critical meta commentary to /r/fatpeoplehate?

You are confusing an implication for an equivalence. I've said that those who are not open to arguments should not have a voice. From that it doesn't follow that those who argue should always be listened to.

I imagine a concrete implementation of this idea as a meme that people themselves would recognize this as a good rule and that they would consider it as a decision aid whether or not to participate in a certain group.

You're effectively just juggling the same argument. If I'm to hang up on salesmen, then I'm not open to arguments. Thus you claim I should not have a voice.

Oh, you mean it that way. Anyway, I’ve already said that it should rather applied to large movements instead of interactions of individuals. The current ideal of free speech can’t possibly realized to its fullest extent either/anyway.