The idea that infidelity can happen in the absence of serious marital problems is hard to accept. Our culture does not believe in no-fault affairs. So when we can’t blame the relationship, we tend to blame the individual instead. The clinical literature is rife with typologies for cheaters—as if character always trumps circumstance. Psychological jargon has replaced religious cant, and sin has been eclipsed by pathology. We are no longer sinners; we are sick. Ironically, it was much easier to cleanse ourselves of our sins than it is to get rid of a diagnosis.