Nobody belongs to just one culture. A Jewish Canadian, for instance, belongs just as much to Canadian culture as to Jewish culture... and in reality, both of those may be less meaningful for him than his political party membership or his sports team affiliation.
No one can state universally what will be meaningful to a huge mass of people, or what priority of meaning they will assign to it.
However, Judaism, like any society, presumes that certain things should be important to its members. It does not enforce these things-- no one will come and physically compel a Jew to prioritize certain things or value certain things-- nor, IMO, should it. But the foundational presumption of the importance of certain things is simply an organizational principle of a society. Virtually every society has such presumptions, and organizes itself accordingly. We act accordingly, and do not stop to re-evaluate the whole society if a few people believe X instead of Y, or Z instead of X, or pay inadequate attention to A and too much attention to B. Societies organize themselves on the large scale; this is especially true for extremely durable societies, which exist for many centuries or millennia, like the Jewish People. And it is also especially true of societies which have a strong communitarian ethos, where members are expected to value things external to themselves; and to understand themselves bound to laws and rules, and not only to their own whims; and are expected to be responsible for the health and preservation of the society as a whole, and are expected not to be completely self-serving.
You just described nationality as a mark of culture. Is a Canadian Jew not a Canadian, and therefore a member of my culture?
Properly speaking, a Canadian Jew is a Jew who is a citizen of Canada. Their primary cultural identity is being part of the Jewish People, since that does not change based on politics or location, and since that identity represents a culture of millennia; whereas the identity of "Canadian" is not even two centuries old, it is entirely a matter of politics and location, and who knows how long it will continue to exist? To say nothing of the fact that "Canadian" as cultural identity is something of a difficult case to make: Canadian according to who? What would constitute Canadian culture besides political citizenship of Canada?
A Canadian Jew is a citizen of your nation, politically equal to any other citizen of your nation; but culturally their Canadian identity must be secondary, if they are at all aware and educated about what it means to be a Jew.
Nationality can be a mark of culture. Nationality is not always equivalent to culture, nor, when it is a mark, is it necessarily the only mark. Nor is it always in the same form. Judaism, for example, is a socioreligious ethnicity: an identity that melds elements of cultural ethnicity, national identity, and religion. These elements are all present in various ways, none precisely equivalent to most other modern Western cultures, and are all intextricably intertwined: one cannot have a truly effective and participatory Jewish identity without them all.
Also, culture is gradated; it's not as distinct as you make it up to be.... To the extent that there are cultural lines at all (as opposed to just zones of grey), there's nothing wrong with having concerns that cross cultural lines, and there's still something wrong with interfering with someone else's life just because you happen to be on the same side of a cultural line.
There is some gradation of culture, sure. But part of what keeps any society intact is having boundaries.
So the thing that's happening here - an American Jew telling a Canadian atheist how he should behave - is completely unacceptable, then... right?
I am only disagreeing with your behavior insofar as that behavior reflects an apparent desire to impose your ideas and values on other cultures, my own presumably among them, to an extraordinary degree.
Are you suggesting that the core of your identity can be reduced to cultural imperialism? Because if not, my disagreement with your behavior should not be an undue infringement. If, on the other hand, your apparent desire for cultural imperialism is only talk, and you would not actually ever support the imposition of your ideas and values onto other cultures, save only for such minimal infringement as is necessary to avert proximate physical danger to minors or incapacitated individuals, then yes, you have grounds for telling me that my confronting your behavior is out of bounds.
It's probably less likely to result in the death of a child than teaching a gay child that homosexuality is a sin.
For the record, I do not agree that homosexuality is a sin, nor do I look fondly upon teaching that idea to any children, much less gay children. However, if we are going to legitimately operate a free society, then the best we can do is to foster aggressive positive identity education in public schools, in the media, and in any other places children and young people are likely to encounter it, in the hopes of countering the unfortunate interpretations of the radical fundamentalists among us.
And, whatever my feelings on teaching that homosexuality is a sin, it is both a cheap shot and a false analogy to try and suggest that it is responsible for more deaths than refusing to vaccinate. People can recover far more easily from bad teaching than from lack of vaccination, and bad teaching, however reprehensible the ideas being taught, very seldom, in fact, leads directly to death-- how often it leads indirectly to death is a matter of conjecture, though I would certainly agree it's far too often-- but lack of vaccination quite often leads directly to death and/or debilitating illness. If the anti-vax idiots keep up the way they've been going, and do a gung-ho job selling the gullible on their line, the death rates in the US, Canada, and Europe are going to start looking more and more like they did 150 years ago-- which is to say, a lot more like the Third World.
What is more, teaching your kid something appalling, like that being gay is a sin, is bad for them. However, they are unlikely to spontaneously begin infecting everyone around them with bad theology-- at least, not anyone who isn't already inculcated with bad theology.
Actually, I think it's a good illustration that your argument is based on a false premise: you argue as if the autonomy of parents shouldn't be interfered with at alll, when in reality, you concede that some restrictions on autonomy are necessary. This isn't about whether there should be a line; it's about where the line should be.
So some imposition on a culture's religious beliefs are okay. Gotcha.
I never said that living in a society made up of many cultures and religious/areligious ideas does not and should not involves certain amount of compromise on all parts.
Part of the price religious people pay for living as part of a larger, nominally secular, society is that they must compromise some of their more extreme ideals: they must let their kids be schooled, be basically medically cared for, and so forth, regardless of any religious teachings that may conflict with that.
The return price that society pays for being made up of many cultures and lifestyle philosophies-- and for being free, rather than a tyranny of particular cultures or ideas over other cultures or communities-- is that we offer freedom of religion and culture, and in pluralism and tolerance, we infringe upon the rights of families to raise their children as they see fit as minimally as is necessary.
We generally permit the parents broad authority to judge what is in the best interests of their child, and seldom impose the will of the government in its stead, even when the parents make unpopular choices, or decisions the majority of us might deem objectionable.
Part of the reality of "freedom" is that people need to be free to make choices-- even choices many or most of us might think are bad choices. That obviously can't be total and complete: even if those freedoms are respected 99% of the time, there will be a few times when people make such extreme, dangerous choices that government must intervene.
The more I think about this, the more I find this attitude abhorrent.
There are no inherent boundaries for empathy, and each person's mind is their own. You have no special claim on the thoughts of a Jewish person just because you're Jewish yourself. If that person chooses to accept the advice of an atheist, then this is absolutely fine, even if it means giving up practices that you think are important. If this bothers you, too bad: in a free society, there's nothing you can do to stop it.
... besides making your best case to the person, of course. But at the end of the day, each person's choices are their own.
I am not suggesting that there be enforcement or external compulsion of any kind of ideas on the Jewish People.
What I am suggesting is that while certainly any individual is free to seek advice wherever they please, the problems of the Jewish community are Jewish, and are to be solved by Jews using the mechanisms of change appropriate to our tradition. Importation of external ideas and transforming them into useful Jewish concepts and processes is certainly an appropriate mechanism of change; but we must be careful that this kind of careful importation and transformation is not neglected in favor of mere syncretism. The former is a way to enrich our culture and help it grow, whereas the latter is destructive to the culture.
But more importantly, the process must be internally driven: if part of our search for answers is to involve the importation of external ideas, it must be Jews who voluntarily and carefully select the ideas to be imported, and Jews who reshape and recontextualize them in order to fit into the spectrum of normative Jewish Thought. It cannot and should not be non-Jews externally imposing their ideas onto Jews, will they or nill they.
Obviously, if individual Jews decide they don't give a damn about Jewish tradition and society, and they just want to do whatever they please and call it Judaism, no one can or should stop them-- in fact, we have one or two individuals on this very forum who do just that. But that doesn't make what they do Judaism, nor does it make what they do healthy for the preservation of the Jewish People. Plus, of course, individual Jews are not and should not be forcibly compelled to retain their association with the Jewish People. There are, unfortunately, Jews all the time who decide that they have no more interest in being Jews, and instead decide to practice some other religion, or be atheists, or whatnot. No one is suggesting stopping them. But their choices are not Judaism, and cannot in any way be said to be contributory to or authentic to Judaism, and by their nature they exclude the chooser from participation in normative Jewish society.
Part of the price of membership in a society is the agreement to abide by the basic rules of the society, to argue and debate and make changes to the society in the ways that society has designated appropriate. One certainly should be free to refuse to abide by the rules of that society, or to argue for or seek change in ways not licit to that society: but in that case, their membership, or at least functional membership, in that society is forfeit. That's just the way societies work: I don't know of any that don't work that way.