As you've described the case, there's something the inventor could do that would save lives. There's also a dispute about how to analyze the notion of a cause. Some would say (your friend apparently is in this camp) that absences—in the case, not doing something—can't be causes. Others disagree and provide accounts that allow absences to be causal. This is an abstract and complicated issue, but how much difference will it make to how we judge the inventor? Suppose I'm in a war zone and happen to know that there's an IED in a certain spot. I see someone running on a path that will take him over the IED and almost certainly leave him dead. Let's assume I even know who it is and know that in all relevant respects, he's an innocent. As it happens, I'm behind a barrier, but I could easily warn him. I don't. He runs over the IED and dies in the blast. Is there something I could have done that would have saved him? We've already said yes. Would it have come at any significant cost? We can stipulate for...

Some people hold the view that if we're doing what we really ought to, we'll give up to the point where giving more would decrease the overall good that our giving produces. The most obvious arguments for that sort of view come from utilitarianism, according to which the right thing to do is the action that maximizes overall utility (good). If I could give more and overall utility would rise on that account, giving more is what I should do. Other views are less demanding. A Kantian would say that our most important duty is avoid acting in ways that treat others as mere means to our own ends. Kantians also think we have a duty to do some positive good, but how much and in what way is left open. I'm not aware of any Kantians who think we're obliged to give up to the point where it would begin to hurt. Who's right? I do think there's real wisdom in the idea that a system of morality won't work well if it's so demanding that few people will be able to follow it, and so I'm not persuaded by the point of...

Since the word "deontological" covers a lot of territory, I'm going to start with an assumption: I'm assuming that for you, the deontological point of view is non-consequentialist and broadly Kantian: it says that we can't treat people as mere means to an end, even if the end is otherwise a good one. (If that's not what you mean, my apologies.) If we have a mandatory vaccination rule, on the surface it's all about consequences: it's to protect people from preventable illnesses. But if we make people get their kids vaccinated even if they'd rather not, that sounds like treating them as means to the end of protecting others, even if there are other values at issue from their point of view. So your question is whether letting them opt out by home schooling their children is enough to make the rule acceptable. We already have such a rule for parents who prefer not to send their children to public school. If that's okay, is there any reason to think a similar rule wouldn't do in the case of vaccinations? ...

Yes and no, though perhaps most importantly no. Saying that something is an art is sometimes a way of saying that it's an exercise of skill, not least of a skill that isn't simply a matter of following a set of instructions. In that sense, cosmetic surgery is an art. Cosmetic surgery also has an obvious aesthetic dimension and no doubt calls on many of the same skills that a good sculptor needs. So all of that is on the "yes" side. But there's another obvious sense in which cosmetic surgery isn't an art, or better, perhaps, an Art . Painting, sculpture, poetry, etc. are Arts in this sense not just by virtue of being skills whose practitioners may have aesthetic goals. They also fit into a familiar set of cultural practices and institutions (museums, galleries, performances, reviews, critical studies, sales, auctions...) that determine what we count as "Art" with a capital "A." Cosmetic surgery isn't an "Art" in that sense, and this is almost certainly a very good thing.