In “The Meaning of Marriage,” Tim and Kathy Keller emphasize that in any bad relationship the natural tendency is to see the other person’s selfishness as the key problem. But relationships only thrive when each partner sees his or her own selfishness as the key problem. After all, your own selfishness is the only one you can really control, the only one you have responsibility for.

This brings us to the truism that, when arguing, “I” sentences are better than “you” sentences. As Daphne de Marneffe writes in her excellent book “The Rough Patch,” think of the different emotional impacts of these two sentences:

“I’d stop yelling if you were more helpful.” And: “I know I’m a piece of work, but I’m trying to control my yelling.”

The crucial step, which several books come back to, is the raw and willful decision each partner must make just to recommit. The relationship is strife-ridden. Every fiber of your body says to retreat to the safety of your foxhole. But you have to go against yourself and lunge toward intimacy.

As Mike Mason puts it in “The Mystery of Marriage,” “A marriage lives, paradoxically, upon those almost impossible times when it is perfectly clear to the two partners that nothing else but pure sacrificial love can hold them together.” This involves, he writes, “a deliberate choosing of closeness over distance, of companionship over detachment, of relationship over isolation.”

That involves a relentless turning toward each other. John Gottman, who I suppose is the dean of marriage experts, describes relationship as a pattern of bids and volleys. One partner makes a conversational bid: “Look how beautiful the sunset looks!” The other partner can either respond with a toward bid: “Wow. Incredible. Thanks for pointing it out!”; or an against bid: “I was reading the paper, do you mind?”; or a turning-away bid, which would be grunting and not responding at all.

Successful marriages, Gottman finds, have five toward bids for every one of the other kinds. The relationship masters, he told Emily Esfahani Smith in The Atlantic, are the people who are actively scanning the social horizon for things they appreciate about the other person and can say thank you for.