Social media teach us that facts and logic make very little difference in argument.
The Israeli-born (now US-based) writer Tuvia Tenenbom has written a series of books recounting his experiences in the assumed guise of a non-Jew (he is blond and Western-looking), to get people to divulge their real feelings.
Arriving in Jerusalem, he encounters a Palestinian professor who is looking forward to an interview with a German journalist, so he can tell him the truth of issues in Israel:
'What is the truth? He shares it with me: the Israelis make sure that he, being a Palestinian, can't own a house [...] he proudly shares with me, he is not a man only of the mind but also a man of means: he owns a house in east Jerusalem, and he also owns another one in a place called Shuaffat.
'There are people who are alcoholics and there are people who are recovering alcoholics, meaning they've stopped drinking. I happen to be a recovering intellectual [Tenenbom was raised in an ultra-Orthodox family] and I draw from my former self to understand this intellectual. Logically it's impossible for a man who owns nothing also to own two houses. But "intellectually," you can explain away everything.'
Shortly after, the writer meets a couple of German girls who have volunteered to work with the Palestinians. He asks one, why:
"Three years ago I volunteered for Israel and I fell in love wth the Jewish people."
"And that's why you decided to come again?"
Three years ago you fell in love with the Jews and that's why you are now helping the Palestinians?
She looks at me in disbelief, very upset: "What are you trying to say?"
In the late 1970s, one of my Birmingham housemates was a young Yemeni who had escaped north through Saudi to Europe. He invited some Libyan students over one evening, and we got talking. They were full of praise for what Gaddafi was doing for the people.
They were also convinced of the Irish Republican cause. They thought they knew all about it, though they had never been there, seemed unaware that the IRA was a decided minority within the Catholic minority, and so on and on. I thought it best not to tell them of my father's several tours of military duty in Northern Ireland. But they were like so many people: on subjects that mattered to them, they 'just knew.'
Cartoonist and writer Scott Adams said recently on his podcast that you should abandon facts and logic and use psychological trickery instead. For example, with someone stolidly repeating the untruth that Trump advocated drinking bleach to kill Covid-19, you could ask their position on the Loch Ness Monster etc, saying that you were testing just how gullible they were.
Bad news, if Adams is right and most debates are bullsh*t contests.
Still, I recall overhearing two Asian lads talking in a secondary school, and one quoted what was obviously an old saying: 'When two people speak, one of them is lying.'