Sometimes, the best-laid plans are laid to waste. Despite all your hopes and dreams in the beginning, and all your good intentions now, it seems impossible to continue your marriage. For many of us, the twentieth-century notion of “till death do us part” has become an anachronism. When life becomes too painful, with too many battles and battle scars, few of us question the notion, at least intellectually, of moving on. Sometimes, Dr. Baris notes, so much hurt has been engendered over the years that it is simply impossible to get beyond it—at least in the context of your current relationship. When people harbor deep, abiding anger, and when, despite therapy, that anger cannot be resolved, it could be time to let go. Even in the absence of anger, one or both partners might start to lose respect for the relationship and a spouse. That might signal the end as well. One couple we know, for instance, divorced after the husband made some poor investments and lost his business an...