Every good relationship contains two things: intimacy and mutual service. I don’t just mean romantic relationships; whenever you find a relationship valuable, it is because you’re getting at least one of those two needs met by that relationship. When you find a relationship hard to sustain, or damaging, it’s because it fails to provide (or provides negative and damaging forms of) these two qualities.

There are lots of kinds of service. To do something on someone else’s behalf is a service. To show someone how to do something is a service. To help someone to accomplish something they were trying to do but couldn’t complete on their own is a service. Some services are offered in exchange for material benefit (money or other things valued by the servicer) — and so form a direct relationship of mutual service — and some are freely offered with no expectation.

And so it is with intimacy. Simply being in the vicinity as I do a thing is a kind of intimacy I might want to receive from another person. Their being my compatriot in doing a task is a richer version. A friend with whom I feel safe to disclose emotions, hopes, and more is richer still. And finally, there’s the thing most people think of with the word “intimacy,” intimate-partner relationships where you’re more honest, open, and supported than you are anywhere else.

All models are wrong. Some are useful though, and I think this one passes the test. When you’re looking to “debug” a relationship with someone that’s not taking, it’s almost certainly for an imbalance in (or lack of) these two things.

I service the pets in my life when I give them food, water, and shelter. I may receive (given the reality of modern life, nearly useless) mutual service. More likely, I continue to keep them well for the sense of comfort and camaraderie their companionship provides. This is the reason that owner-aggressive pets are rarely tolerated for long.

When a relationship doesn’t ever seem to click and work with someone, it’s probably because one party in that relationship feels they’ve not received either intimacy or service that makes it worth continuing. This is why you’re frequently advised to offer value — usually service, but sometimes the solace of commiseration — to strangers before you ask for something you need from them.

It’s not a revolutionary idea, this intimacy and service thing. But I found it clarifying, useful, and thus worth a note.