To start with, the phrase “civic-national multiculturalism” tells a lot. It might suggest that until one starts thinking about multiple cultures at once–how they would cohabit within one society (multi-cultural-ism)–, it would be preferable for one first to grind out the understating of “one” culture, the basis for individuals’ integration into a human society. According to my research, a particular culture is a particular human societal structure, the system of values and norms, laws loyalty to which normally ensures its additional (self-)reproduction in the global system of cultures (the culture system). But what would prompt the members to act likewise? The answer is simple: They enjoy just this way of being human among many ways available within the culture system. This account of culture overcomes racism explaining humanity predominantly in biological terms. Racism, culture-nature confusion, was a fundamental ideological error by the German national-socialists (why don’t qualify it as “naturalistic fallacy”?), having led to WW2 overwhelming catastrophe.
Thus the notion of multiculturalism seems deeply controversial. There is no “multi”, nor in nature neither in culture, but always a particular culture, the way of life its members enjoy. Culture B adopts some useful trait from culture A, and/or vice versa, voluntarily, as a means to the betterment of its own way of representing the human proper. Therefore no “multi” is produced through cultural exchange or otherwise, but the same particular culture becomes more rich in its affordances. The same concerns immigrants: They choose voluntarily to assimilate or not to assimilate based on relative attractiveness of their own culture in comparison with host culture. In the same way host culture have the same right to preserve itself until it represents the most attractive way of life for its members, the ultimate means to which is the nation-state. Thus, this calls for compromise. Immigrants who want to preserve their way of life should simultaneously understand that host culture members have the formally same rights and that there is no more territory as well as a nation-state, serving host culture’s self-reproduction, other then those it already employs, so immigrants should abide by its values and laws. Otherwise, expect conflicts based on fear and hate, not the “accommodation of the differences”, and negative trends like the rise of neo-fascism–the return/the reproduction of the errors of the catastrophic past. Neither party will become successful in the end.
These considerations are relevant to the topic also in several other ways. It is true to define Europe as “secular Christian”, with Christianity characteristically emphasizing the free will. This model of culture follows this tradition when fundamentally uses the term “voluntarily”. The same affords such understanding of culture that theoretically, is very close on giving up the agency-structure divide. The model, too, sees culture being compound thus fragile. For example English culture features not only Baconian naturalism but also the opposite trend maybe best exemplified by Lewis Carroll’s tales about Alice’s adventures.
As for “the crisis of secularism”, it truly, exists; though the presence of Muslims in Western Europe is somehow a challenge to it, the crisis is rather structural and lies in modernity’s narrative or worldview, as predominantly tied to both the scientific method (again, naturalism) and the economic way of thinking. However, generally this does not predict its final crisis at all. There are no successful ways copying the historical past.
in this light, multiculturalism seems to me more a program then a theory about facts. It resembles an agenda that consciously or not, seeks for conserving or expanding “minority” in the host culture. Not surprisingly, as each is naturally biased to the way of life they prefer in the culture system. But a compromise based on the basic understanding that universally, each have right to enjoy life they prefer most and that their nation-state is the watchdog to defend the right would diminish the possibility of conflict not only in a particular society but also in the culture system.
Saying one is “biased” is not just an offence. Insisting on this means underestimating a message by Max Weber’s innovative work “Nation-state and economic policy” warning “colleagues” that human science is subjected to the value judgment of different type and that scholars should learn to control it. The past errors or tragedies, as well as the current ones, have shown how much he was right not only theoretically but also practically. Presently playing zero-sum cultural game even more goes against this wisdom.
The theoretical foundations of this line of thought about culture explaining it as the tool specifically for serving the universal ultimate human interest is available at http://philpapers.org/rec/KANTCM.