"Do you look at nationalism the same way you look at religion?"

This was a question asked by a page I follow on facebook. I originally wrote an answer and posted it here last year, but I have largely rewritten and considerably expanded it.

Nationalism is definitely in some fundamental ways comparable to religious affiliation, in that it is driven by the desire to belong to a group, or simply passed down within kinship-groups as part of what affiliates your family with its wider social group/community. If we exclude the real or supposed social functions of religion and nationalism, then on that basis they may both seem to be equally irrational.

Nationalism and nation both need to be defined to answer the question in any depth as they will mean different things to different people. The OED definitions may be somewhat instructive:

nationalism, n.: 

1. a. Advocacy of or support for the interests of one's own nation, esp. to the exclusion or detriment of the interests of other nations. Also: advocacy of or support for national independence or self-determination. (Whereas patriotism usually refers to a general sentiment, nationalism now usually refers to a specific ideology, esp. one expressed through political activism. In earlier use, however, the two appear to have been more or less interchangeable.)

nation, n.:

I. A people or group of peoples; a political state.

1. a. A large aggregate of communities and individuals united by factors such as common descent, language, culture, history, or occupation of the same territory, so as to form a distinct people. Now also: such a people forming a political state; a political state. (In early use also in pl.: a country.)In early examples notions of race and common descent predominate. In later use notions of territory, political unity, and independence are more prominent, although some writers still make a pointed distinction between nation and state.

...

c. A group of people having a single ethnic, tribal, or religious affiliation, but without a separate or politically independent territory.

d. With the: the whole population of a country, freq. in contrast to a smaller or narrower body within it.

For our purposes we may consolidate this down to two key referents: the people of a nation-state, and the nation-state of that people. Therefore the definition of nationalism depends on what meaning of nation we are referring to: the people, or the state - the ethnic referent, or the political one.

If your idea of your nation is one which is inclusive of people of recent foreign background, then a strong sense of affinity to that nation is unlikely to be divisive or destructive to your society - foreign policy aside. However I suspect that that is not the case with many (most?) people who consider themselves nationalists: nationalism, as opposed to patriotism, often carries more exclusive, racial, connotations, in my experience, even if those connotations are not quite part of the definition. That is, nationalism with respect to a people defined in part by a perception of common descent. This perception of common descent we may call "race". I say "perception of" because the reality or not of whatever degree of homogeneity is implied is a different question, somewhat irrelevant to the present point as it is not a discussion of the objective validity of the ethnic sense of nation.

If the ethnic sense of the word nation is "people (most of) whose ancestors have been of the nation for longer than folk-memory", this is not necessarily unfair. (I have the impression that it is a fairly common element in the definition of ethnic groups.) What would be unfair would be exclusion from something on the basis of not being of a particular nation; which is the same thing as, exclusion from something on the basis of not being of a particular ancestry/race. This is clearly unfair.

It is very close to exclusion from something on the basis of not being of the correct ethnic group. This too will almost always be unfair: I say almost always because "ethnic group" implies a cultural element (often as well as an ancestral one); conceivably there could be a justifiable reason for an exclusion from something on the basis of cultural incompatibility. However, a further qualifying factor here for exclusion of an ethnic group to be justified is that the (cultural) element that is the basis for the exclusion must a key and inalienable aspect of that ethnic group - in other words, no individuals are being unfairly discriminated against on the basis of ethnicity, even if that was not the intention. In short, it is people who have the incompatible element who are being excluded; not, people of a group with a relatively higher incidence of the incompatible element. It must be that particular element that is the reason for the exclusion: this must never be confused with exclusion on the basis of ethnicity. Exclusion on the basis of cultural ethnic difference is very little different to exclusion on the basis of racial (ethnic) difference: indeed the two are equally unjust. I find it hard to think of a real-world example of a trait that is ubiquitous to a certain ethnic group that is also significant enough to justify exclusion from something; though doubtless examples do exist.

So what if the criteria by which you define nation can be shown to synchronise with valid criteria for preferring one group to another? Perhaps that might justify a kind of nationalism in that particular superior nation. We must consider whether any such criteria exist: as far as I can see, perhaps the only even arguably valid reason for preferring one group of people to another would be a "superior" shared morality. However, if that is the only justifiable reason for preferring one group to another, then nationalism (if defined as preference for one national group over others) is still wrong: because we clearly cannot define the national basis of nationalism out of nationalism. In other words, if your nation is morally superior (and if moral superiority is a reasonable basis for preferring some individuals over others), then it must be for the moral superiority that the individuals are preferred, not for their nationhood. Again the problematic trait must remain the basis for discrimination, however easily it might be confused with ethnicity.

Of course, what constitutes moral superiority is extremely culturally and individually subjective. To give just one obvious example, some groups, especially conservative Abrahamic religious groups, consider homosexuality to be morally wrong; whereas I will go to my grave maintaining that they are morally wrong to think so, and that my morality is superior. Possibly it could even be shown philosophically that I am objectively right, although I think that probably depends on how you define morality and perhaps what you consider to be its purpose.

Regardless of whether you define your nation by the borders it lives within, and/or a shared culture or world-view ("ontology"), or by perceived shared ethnic origins (however that is defined) or shared ancestry (however that is defined, and whatever its historical reality), giving preference or favouritism to a group of people based on any of those criteria is obviously unjust (at best baseless, if we leave out the moral question). There may be problematic traits which are linked to particular nations or ethnic groups for cultural reasons; but in such cases, the problematic trait must be the basis for discrimination, not the ethnicity. The trait must be identified, defined, described, and its presence assessed in each individual, rather than trusting to prejudice about other ethnic groups.