Does the entire paternalistic argument really rest on that? What if you believe humans are rarely entirely rational and it's a spectrum (e.g. If I was addicted

Does the entire paternalistic argument really rest on that? What if you believe humans are rarely entirely rational and it's a spectrum (e.g. If I was addicted to heroin but trying to quit I'd probably be less rational when I really wanted a fix than if I was a pack a day smoker doing the same)?