The way I usually discuss things is by responding to everything I can. Even if it's just that I agree. I do this especially if there's something I disagree on, and when I got to the part I disagree on, I'm not blunt. This is just window dressing. But often it makes the other person more likely to listen to what I'm saying. Not always, but often. I very rarely genuinely cannot see the other person's perspective, however, so it's easier for me to say things like, "I see what you're saying, but..." I feel like this would just seem like bullshit coming from you, so I'm not sure how to tell you to have a discussion instead of an argument except maybe that driving the discussion in a certain direction by only talking about something you personally take issue with, and not acknowledging any points the other person makes, is sort of going to invite an argument.

I think primarily the whole picking out things you disagree with and only commenting on those is what grates me. My mother does something similar: she only responds to anything with corrections. It feels like I'm just there as a critical exercise for your beliefs, instead of an actual person who gets to be genuinely excited or emotional about something, who gets to be my own person instead of a reflection of what matters to you.

I think the whole agreeing on the presuppositions to discussion is probably a large part of what's missing and what makes this not work.

I feel I have to rescue whatever you're attacking because I'm a contrarian. Because whatever you're attacking isn't there to defend itself.

I'm not saying you have to accept what I'm saying, or agree with me or shut up. I don't know what to do really, except not write about things that are likely to incite arguments.