At present, the main issue is that we each have important beliefs that we don't think we can share.

Being able to share differing beliefs has more to do with whether you can both remain civil about important things than whether you agree. I regularly and enthusiastically pick apart minute disagreements between myself and my friends, and would feel as though something were lacking if I couldn't - but we can switch topics from politics to polenta when someone gets fed up and there are no hard feelings. If you can't do that with your girlfriend, that indicates a deeper-running incompatibility than merely disagreeing on rationality. Even if you agreed on all the big issues, it would be miraculous for you to make it through life without ever arguing, and being able to argue without it having it destroy your relationship is an essential skill.

I think I'm quite rational and have a decent understanding of aspects of rationality that I haven't managed to implement yet. I think karma is a very imperfect measure, but I'll note that I have more than 100 and less than 400.

Huh? Karma on this site primarily shows positive contribution/participation (if you are able to contribute positively), treating it as a "measure of rationality" is a bizarre perspective. Please try to outline your position on the specific questions I suggested, or something of that kind, it's hard to make such a decision in a well-known case, but yet harder to construct fully general advice.

For another example, why do you think it's important to get away from magical thinking? Is it? What is your motivation for thinking about rationality, and for dispelling the other person's confusion? "Compatibility" of worldviews?

It is possible to make a relationship work in which each party has a role in the general neighborhood of "the rational one" or "the emotional one", as long as the relative places and merits of these roles are acknowledged by both parties. Since you say she's prepared to admit to her mood swings, this may be doable. My proposed checklist:

• If she suffers from an extended period of depression, is she prepared to address that (therapy, antidepressants, ice cream & sad movies, whatever she finds works for her), or would she let it greatly interfere with her life and your lives together?

• How averse to your atheism is she? How averse to her (presumable) theism are you? Do you have enough else to talk about and enough ability to skirt the topic that it can avoid being a major point of contention between you? If you want kids eventually, can you come to an agreement about how to raise them re: religion?

• Does her magical thinking lead her to do anything profoundly instrumentally stupid, or does it mostly just make her sound a little silly occasionally?

• Can you respect her, as well as love her, in spite of her failures of rationality? Or would you be hoping in the back of your mind forever and always that she'd eventually wise up and be a more rational version of herself that you could respect?

• Are you compatible on other long-term axes? (Financially, politically, life goals, desire to live in a particular location, opinions on family and homemaking, etc.)

If you can give the "right" answer to all of those questions (I think it should be obvious in each case which answer would be best) then go for it and the best of luck to you. If you can't, you either need to address the situation and fix it, or move on.

How strong is your own understanding of rationality? Why are you an atheist, (why) do you believe science works, what is the difference between one person who is actually right and another person who is merely confused, etc.? How smart is she (that is, how easy it'll be to positively apply more confused and complex arguments, not requiring of you great feats of persuasion)?

I'll be interested in what other people think about applying the corpus of Overcoming Bias directly (doesn't seem like a generally good idea to me, requires a person to be of a kind that'll maintain focus for extended period of time).

I need relationship advice and I trust the wisdom and honesty of this community more than most of my friends. I created a new account to ask this question.

I'm with an incredibly compassionate, creative woman. She excels at her job, which is a "helping profession," and one which I believe improves social welfare far more than most. The sex is outstanding.

But she loves magical thinking, she is somewhat averse to expected-utility calculations, my atheism, etc. She is, by her own admission, subject to strong swings of emotion and at greater than average risk of longer-lasting depression. We love each other but are scared that our differences may be too great.

How would you personally feel about a relationship like this? How should I go about deciding whether to continue this?

Added: We have been together more than 6 months. She has learned a decent amount about my way of thinking, but I have not pushed it on her. I frequently mention how great rationality is (but also mock myself to make sure we're all having fun).

I wish I had confidence that trying to convert her to my way of thinking would have net-benefits for her and for the world long-term, but I don't. Not that I'm convinced trying to convert her is a bad idea on utilitarian grounds either, it just seems risky.