I've mentioned this before, but I'm highly skeptical of the concept of "little c" culture, at least as it's typically invoked.
The term Culture, with a capital C, is sometimes used in the social sciences to denote what has also been called "the human capacity for culture" or "the human propensity for culture"; that is, the tendency of humans to gather together in groups, build institutions and systems of social norms, pass down knowledge generationally, etc. It's our wont to do social stuff larger than the family unit, basically. And, to be clear, this notion of Culture is something I very much believe in (I mean, how could you not?).
But then there's culture, with a lower-case c, which is a count noun rather than a mass noun. That is, one talks about "a culture": French culture, Japanese culture, American culture, etc. And this notion, I'm extremely skeptical of.
For one thing, it's not clear at all how one is meant to coherently draw the boundaries between different cultures. Culture often tends to vary (roughly) continuously, both over time and across geography. It's not clear, for example, if one should consider the American culture of today to be "the same one" as the American culture of 200 years ago, and/or consider the American culture of 200 years ago to be "the same one" as that of 17th century Britain, etc. This is true geographically as well: in precisely what provençal village does "French culture" transition to "Spanish culture"? You might try to use language as a proxy for this question, but even that won't work! The Romance languages (the family including French, Spanish, etc.) are a dialect continuum. There is no village where they suddenly stop speaking French and start speaking Spanish! The "French" on one side of the border and "Spanish" on the other may well be more similar to one another than either is to the Paris or Madrid standards.
In much of the world, deliberate nation building over the last few hundred years has obscured the difficulty of defining cultural boundaries. In France, for example, before the introduction of standardized education only a minority of the country spoke a Romance dialect that we would today recognize as "French". The ancestor of contemporary standard French was the dialect specifically of Paris and the surrounding region, while the rest of the country spoke... other stuff. Now, due to the policy of teaching standard French in schools and using it in most media, it is spoken by an overwhelming majority of the country.
[Sadly, it's the middle of the night and I can't dig up the source with exact numbers and years at the moment; I'll try to add it in a reblog tomorrow. IIRC the estimates were: < 30% speaking French before 1700, greater than 90% today. However, I don't feel comfortable making those specific claims without a source in hand, so take that with a grain of salt.]
This fact is a microcosm of a broader trend —that points of national and cultural unity, often interpreted as arguments for political nationalism, are more often in fact products of it.
But, prior to such nation building projects, the cultural and linguistic map of Europe looked much more like the cultural and linguistic map of Africa or the pre-colonial Americas, an intricate hodgepodge of different language varieties, institutions, customs, and political units, often with no clear line where one ends and another begins. This is not an aberration, this is the norm for human societies.
This brings me to my second point of concern over the notion of culture: there are various sorts of human activity that comprise big C Culture, and they don't always correlate with one another. Language isn't always correlated with government which isn't always correlated with tradition, etc. There are practices, concepts, institutions, and so forth that are shared by multiple "cultures", and within each "culture" there are practices, concepts, and institutions that are not shared by everyone. Thus, rather than a collection of discrete units (or even of a field of pure continuous variation between different extrema), the cultural landscape has a character more akin to a tapestry: different elements of Culture interwoven in complex and unpredictable ways, overlapping in different combinations across the map.
The consequence of all this —that cultural variation is continuous, that internal variation within "a culture" is often comparable to or greater than external variation between "cultures", and that different elements of culture often vary on axes totally orthogonal to one another— is that drawing coherent cultural boundaries can be a very hard thing to do indeed!
Finally, compounding all this difficulty, there's the issue that different people have different opinions on where we should draw these cultural lines, and those opinions are often politically motivated. Taking culture as a fundamental element in your understanding of the world requires taking a position on a thousand political debates large and small just in order to have a coherent picture of the ontology of human society. This is a very bad position to put oneself in, clarity-of-thinking wise!
Of course, the notion of "a culture" is just an abstraction, and in some cases it will be an abstraction that models reality better than in others. But in general, I tend to find that people treat culture in this sense not as an abstraction, but as a fundamental part of reality. And I think this is an extremely dangerous thing to do, both in terms of its political consequences and in terms of its impact on one's ability to think clearly about the world.