So the answer to “Why is it relevant whether I would convince some third party that isn’t here?” is “You don’t seem likely to change my mind much but this should change people’s minds away from your position.”.
Why would you think it’s undesirable that he changes people’s minds away from his position? After all, you think his position is false. You presumably want other people to believe truthful things. So you should want other people to believe that his position is false—as far as you’re concerned, changing people’s minds away from his position is a good thing.
You’d only think it’s undesirable if you’re more concerned about him winning (because he’s your friend and the others aren’t) than you are about spreading the truth.
In the example I mentioned, I have a contrarian third position where I think the other positions have some good points and (mostly) some bad points. This means two things:
There are some places where his side genuinely right and the other side is wrong, and it’s unfortunate that people on his side shoot themselves in the foot by using bad arguments instead of defending the places they are right using good arguments.
By treating bad arguments as good epistemology, they avoid being truth-seeking and make it harder to correct their wrong beliefs. That’s unfortunate since I think they should correct their wrong beliefs.
Why would you think it’s undesirable that he changes people’s minds away from his position? After all, you think his position is false. You presumably want other people to believe truthful things. So you should want other people to believe that his position is false—as far as you’re concerned, changing people’s minds away from his position is a good thing.
You’d only think it’s undesirable if you’re more concerned about him winning (because he’s your friend and the others aren’t) than you are about spreading the truth.
In the example I mentioned, I have a contrarian third position where I think the other positions have some good points and (mostly) some bad points. This means two things:
There are some places where his side genuinely right and the other side is wrong, and it’s unfortunate that people on his side shoot themselves in the foot by using bad arguments instead of defending the places they are right using good arguments.
By treating bad arguments as good epistemology, they avoid being truth-seeking and make it harder to correct their wrong beliefs. That’s unfortunate since I think they should correct their wrong beliefs.