The Catalan referendum raises two issues. First of all, there is an issue concerning legality and democracy – the Spanish government alleged that the referendum went against the Spanish Constitution. Secondly, there is an issue concerning independence and self-determination – many think that Catalans are entitled to independence, or to a greater autonomy, and the referendum was apparently aimed at eliciting a plebiscite on that. These two issues generate a further puzzle. If the referendum is not legal, then Catalan independence, if and when got, is not a new constitutionally enforced legal order – a state entity dividing up or implementing autonomous spheres within it. Rather, it is a genuinely unilateral and not consensual secession. (Consensual secessions are possible – think about Norway seceding from Sweden in 1905, or the Supreme Court of Canada’s verdict on the possibility of a legitimate secession of Quebec. Some authors, Cass Sunstein among them, claim that a right to secession contradicts the very spirit of constitutionalism, as it encourages dissenting minorities to secede or to use the prospect of secession as a threat against majorities. Allen Buchanan suggested to allow a constitutional right to secession, provided that its implementation is constrained by supermajoritarian restraints.)

In recent political and moral philosophy, there is a discussion on the ethics of secession, namely on the moral reasons favoring secession. Some authors assimilate the right to secession to the right to revolution – i.e. to the right to rebel in front of extreme and systematic violations of basic human rights (Allen Buchanan includes among basic human rights the right of a minority to legal procedures of self-determination, compatibly with the national sovereignty). In such an approach, secession is a sort of extreme measure against gross and persistent injustices. Secession is a remedy for previous injustice.

By contrast, other authors claim that any group can abandon its fatherland in the name of a primary right – such as the right to self-determining as an ethnic or cultural group (peoples or nations having a shared ethnicity or culture are entitled to their own state). Alternatively, secession can be made out of a common will: if a group decides autonomously to secede, through democratic procedures, this group is entitled to secession. In such an approach, the right to secede is not a remedy to previous injustices or rights violations. Rather, it is an original right, or it is connected to original rights such as self-determination or autonomy. Catalan secessionists, or at least those of them who sponsored the referendum, are likely to assume such an approach. Of course, there is a reasonable doubt: the Spanish government, through the acts of these days, may make true the view of secession as a remedy – namely, it may violate human rights, thereby justifying secession.

An assessment of these two approaches needs reflection on a specific point. Sovereignty is exercised over a territory, it is an entitlement to an exclusive jurisdiction over a territory. Secession, then, is a demand for exclusive jurisdiction over a given territory, a demand for a jurisdiction able to supersede state jurisdiction.

Jurisdiction over a territory needs justification. A possible justification makes appeal to functional reasons. Exclusive state jurisdiction over a territory is needed to protect citizens’ human rights – security above all. If so, a state that violates the human rights of its citizens is no longer entitled to have jurisdiction over the territory where these violations occurred. Then, secession is justified as a remedy for the violation of the human rights of secessionists. As already said, Catalans cannot invoke this kind of justification – their right to self-determine as an ethnic or cultural group, or as a community of voters, can justify independence and autonomy within the rule of law, within Spanish sovereignty. A remedial view of secession reminds us that, before seceding unilaterally, groups and nations can pursue their self-determination in many alternative ways.

It might be argued that democratic voters should decide on borders – the democratic demos establishes its borders. If, even without antecedent gross violations of human rights, a group has the will to secede, this should be granted to them. However, what would be granted is the right to determine unilaterally the borders of two groups – the seceding one and the rest of the citizenry. Catalan voters, merely because they live in Catalonia, would establish Spain’s borders. Of course, a completely different matter would be a referendum extended to each and every Spanish citizen. Bilateral secession is perfectly justified on the ground of democratic consent. A plebiscite theory of unilateral secession, by contrast, is unable to explain why a group is entitled to claim jurisdiction over a given territory. If the Spanish government does not violate Catalans’ human rights, then it has entitlement to power in Catalonia. However, if the Spanish government uses this referendum as a ground to violate or fail to protect human rights in Catalonia, then this obviously makes a difference – secession can turn out to be a morally legitimate option.

Mere nationalism would have it that unilateral secession is justified because a people should have its own state. This approach cannot justify moral costs, though. Since it is possible to acknowledge nations’ autonomy within multinational states, as in many governments today, unilateral secessions are not justified, especially for the possible costs in terms of conflicts and discriminations. Moreover, there are striking theoretical difficulties in giving an account of the concept of ‘a people’. Finally, egoism can be suspected, when one thinks about the fact that Catalonia is a very wealthy part of Spain, presumably unwilling to lose its wealth and privileges.

These arguments are not definitive, of course. However, there is no easy way to grasp the precise moral reasons in favour of nationalist aspirations in the heart of Europe. The worry for unexpected violence remains.