How to fairly evaluate someone's ideas without having to either fully accept them or fully reject them.
This is basically the difference between western and eastern philosophies. In the west we tend to view that one person/party's idea is absolutely correct. In the east it is generally viewed that the truth lies somewhere between the two ideas. This mindset can help help avoid picking sides and becoming entrenched is what has typically become a populist dichotomy between two usually flawed ideas (at least that's how I see it in the US more often than not).
I also have frustration when I pick a middle ground or outside the box idea. For example, with the prevalence of prenups and the variety of living situations/arrangements, I see the solution to the debate over non-traditional marriage to be making marriage documents a private contract to remove the government from trampling anyone's rights. Even the LGBTQ community is not fighting for everyone's right to marry - what about incestuous (with sterilization or longterm contraception to protect genetics) marriage or polygamy.
I haven't laid out all the details as this is an example but I can see the downvotes rolling in already...
In my case, it may be because I'm borderline aspy. I care more about the idea than with the person (or camp/side/school) that said it. But that doesn't leave me knowing how to teach yourself to do that, since it came rather naturally to me.