That is (in this context), don't bother trying to give truth (or even have a reasonable conversation) with those who simply will not listen. Zealots, shill, propagandists... it's like talking to a brick wall. If anyone has a technique for getting them to stop being a brick wall and start actually engaging with what you're saying, I'd like to know what it is.

but fanaticism is more often a problem than not. fanatics tend to not really understand what they're talking about, or twist it to fit what they want it to be about.

> Fanaticism: Excessive enthusiasm, unreasoning zeal, or wild and extravagant notions, on any subject, especially religion, politics or ideology; religious frenzy.

note -- not talking about any particular "thing" here. just commenting about passion vs. fanaticism in general.