That's such an extreme reductio ad absurdum that you could use it on anything. If you have no obligation toward others because "you do not have to set yourself on fire to keep others warm", therefore, you may argue that "You do not have feed your baby once they're born even when you have plenty of food, and it's fine to let them die".
Most people that say we have an obligation toward others think that people ought to help others at least until it unduly burdens themselves. That undue burden interpretation might vary between society and culture but death or severe burn is generally agreed on as an undue burden to severe to ask of anyone to give someone else a paltry amount of warmth.
There are many intersecting values in life. One might say that no one has any right to use violence toward others as that's usurping other people's self-autonomy rights, but that could also be taken to the extreme that you have no right to defend yourself when others are about to kill you. Afterall, there are no exceptions allowed! Only extreme positions!
Saying that having obligation to pay back to the society that has given us the infrastructure to be successful before we were even born is the same as having to kill ourselves just to give minute comfort to someone else, makes no sense. No. Be a person that help others as much as they could without sacrificing your very life for it. The more you do that, the better of a person you are. Kindness is a virtue. You could even still maintain some wealth and still help others.
Sorry for the delay @sylph. Been rebuilding my home and only got back on steem today.
firstly a child is a consequence of a parents actions, ergo responsibility for it exists with them logically by cause and effect chains of action. you can only have an actual obligation to something you agreed to, or as a consequence of what you have done. BTW, if you are going to make an analogy, at least make one which has the same level of resolution as what you are arguing against, otherwise you're not actually making a logical point, just a strawman.
Secondly, you pretty much missed the point I was making entirely, and then made it for me in your last paragraph. You reacted to an old saying (I can't find its origin actually, really irking me), one which means effectively "don't put everyone else's needs before your own, otherwise you will get burned". This excerpt does well to explain the meaning of the phrase (though the source is albeit a bit pants):
from http://www.yourownlife.org/not-required-set-fire-keep-people-warm/
Also, as a point of order: Violence is not the same thing as aggression. This may seem like mere semantics, but it is an important distinction. Aggression requires the initiation of violence. It does not include violence caused by defending from aggression. Its why libertarians and voluntaryists tend to follow the NAP not the NVP, or pacifism.
What is an "undue burden" then? Because that definition is critical if you want to enact a high resolution solution to society. Its not trivial at all to decide, because it doesn't just vary between culture or society. It varies between individual people within those societies and cultures, and that is the crux of the matter.
It's worth noting that many societies do believe death is necessary, nay laudable, and have done so over time. We may consider it barbaric to think human sacrifice is needed, but many cultures used to and some of our own still do. We praise soldiers, and sing to their glory when they are sent to bleed for our nation's interests, then abandon them in red tape once their minds or bodies are spent. All for that lovely oil that fuels and makes so much of our modern life. Oh sorry, that's right, it was "to protect our freedom" we killed people, then let our government take away those freedoms it so vociferously claimed it had to protect for us. Now apparently, its job is to protect us from those freedoms instead.
Your last paragraph is quite eloquent, and as I said, is the proper interpretation of the saying that you were rebutting. So I'm glad you at least understand the proper interpretation of the phrase, even if you didn't realise that is what the saying meant.
I also will agree that Kindness is a virtue, but Public Welfare is not kindness to my mind. It is a dangerous trap, disguised as something much shinier and tastier, and when you bite into it the jaws spring shut. Charity is kindness, but charity is voluntary, and that is why it is actually kind. A person actively wanting to improve another's lot? That works.
Welfare is not this. It is a mandate of how much one must be willing to sacrifice, and how it must be spent, all with no regard as to whether or not that individual consents to it. One must accept that fact to move past the concept of public welfare via the state being for the good of man.
Otherwise one must justify acting unethically to be ethical, and be able to do it all the time for every action taken by it.