On the other side you pile up all the evidence for leaving and against staying: all the bad things in the relationship, all your fears, all your hopes for being on your own again.

All by yourself, you do what the opposing lawyers do at a trial, each lawyer piling up evidence on one side or the other. Then after acting as lawyer for both sides, you act as the jury, looking to see which pile of evidence weighs more. It’s instinctive. It’s universal. And it’s guaranteed to drive you crazy.

Weighing the pros and cons of staying or leaving isn’t like weighing a can of tomatoes against a box of cornflakes. It’s like placing puppies on a teeter-totter: everything constantly moves and shifts, nothing stays pinned down.

When it comes to relationships, the balance-scale approach is the problem, not the solution. It gets us into trouble, not out of it. How can you weigh the things you know about your relationship in the present against a huge uncertain future? How can you weigh a problem that’s bad for you against the knowledge that a lot of people have this problem but don’t seem to be breaking up their relationships over it? How can you weigh a problem that makes you want to scream today against the possibility that it won’t bother you so much tomorrow?

With the balance-scale approach pieces of evidence keep sliding in and out of the picture. You try to add things up that don’t add up, to compare things that can’t be compared. Like a tenderfoot in the woods, the more you try to find your way, the more lost you get.