Suppose that I would not be harmed at all if you stole from me the hard drugs I own and prize, because without your intervention I would use the drugs to my
The individual has an interest in personal sovereignty, in not being subject to such paternalism, even if frustration of the interest does not harm him or
reduce his welfare.
It seems to me that this distinction between interests and "welfare" (I prefer the term "wellbeing," since "welfare" is often used by economists in reference to preferences, which would complicate this account) is in some sense rooted in a tension between idealistic and materialistic accounts of the self. From an idealistic point of view, it seems like when trying to take us into account, what should be important is whatever we think is important. We are morally relevant because we are experiencing subjects (to steal Reagan's terminology), and what matters for moral thinking is what affects our life experiences. Taking this view, the important factors are our interests -- the things that matter to us.
But from a materialist point of view, it seems like when we think about what matters when taking others into account, we should seek to understand the things that are good for them, and then base our decisions on those considerations. From this perspective, I would expect someone to focus more on wellbeing.
So what matters, how we think about what's good, or how objective states of affairs actually impact us? I'm not entirely sure. But I think I'm happy just to characterize the problem