Sir--you're absolutely right on target. The science of addiction, which is nascent at best, isn't relevant. We say "addiction" because we don't have a more general term for behaviors that grow when you feed them. True chemical addiction is only one crude form of the more general concept. There are numerous other structually similar behaviors where gratifying a desire inexorably increases rather than satisfies the craving. Porn is one but many activies, some normally benign and not even particularly pleasant, can work this way. Exercise, dieting, sex, cutting oneself--almost anything can get out of hand. Even alcohol and drug abuse are almost always long out of control, often for years, before one is physically addicted.