After a partner cheats, how do we forgive, forget and move on?

Trust within intimate relationships is a terrifyingly amorphous concept, when you think about it at any length. The basis of the trust between you and another person is nothing more than a verbal contract; a promise to be faithful to whatever sort of commitment you have made to one another. Even in marriage, the basis is fundamentally no more than a verbal and conceptual promise, though one you both take so seriously that you’re willing to put your personal comfort and half your stuff on the line for it. The promise that links you to the other person is tenuous, like a thin string connecting two boats. Waves on either or both sides, if they’re big enough, can snap the string or rip it forcefully from one side. To keep a promise, both people have to work to maintain it and remember why it is worth keeping.

This, I suppose, is partly why serial cheaters tend to cheat. The initial stages of dalliance, flirtation and excitement are so much more thrilling than the frightening but meaningful work of real love.

I was sitting at my desk late one evening this week when my phone rang. It was an old friend who lives abroad – the sort you may not see for months or sometimes even years, but when you do see them, the machine of your bond judders back to life right away, and the cogs run smoothly. He was calling because he needed someone to talk with. His wife of five years had slept with a colleague on a work trip some months before. “I want so much to forgive her and I told her I had. I know that she’s sorry and she really means it. But I resent her so much. I really want to forgive her, but I know I’m horrible to her. I’m snappy and mean and I know I’m just pushing her away.”

This news was a shock. These two are that good couple everyone knows; the couple you think will probably stay together out of all the couples you know. Most of us know the deep sting of infidelity, but I could only imagine the pain of someone so long loved and trusted committing a betrayal like that. With sympathy, I told my friend this and listened to him, because there wasn’t much else I could do.

His predicament – of genuinely wanting to forgive, but being obstructed by the natural feelings of anger, loss and real grief after a betrayal – reminded me of the work of one of the most prominent living philosophers. Martha Nussbaum's Anger and Forgiveness is a careful work exploring the dilemma faced by my friend and lots of other issues. In it, Nussbaum describes the scenario where we have rationally decided that we want to forgive our wrongdoer, but can't seem to get there. Interestingly, she describes some of the obstacles that slow us down as being narcissistic at base. Through anger, we gain a false sense of recapturing some of the control we feel we've lost.

Nussbaum insightfully points out that trust is neither wholly a belief nor an emotion, but a weird hybrid thing that leaves us incredibly vulnerable. Of course it isn’t always wise to try to repair an important relationship after a betrayal, but where the wrongdoer is contrite and we’ve decided we really want to forgive, it is possible. “But a spouse, a lover, a child [. . .] there usually remains something nice about them that is not utterly removed by whatever it is they have done. The target of anger is the person, but its focus is the act, and the person is more than the act, however difficult it is to remember this. This nice something could become another knife to twist in the wound of betrayal (to the extent that a person is appealing, it’s harder to say good riddance), but on the other hand it could also be a basis for constructive thought about the future – in a restored relationship or some new connection yet to be invented.”

Whether or not the relationship is worth repairing, we should probably forgive when there is contrition. Resentment can salt the ground of new relationships as well as old ones.