The President of the Catalan government, Carles Puigdemont, has announced his intention to hold a referendum on Catalan independence on October 1. The Spanish Constitutional Court made it clear that Catalonia does not have the power to call such a referendum, as the question of sovereignty lies with the Spanish people as a whole. Yet Catalan nationalists seem determined once again to disobey the Constitutional Court, as they did on November 9, 2014.

The Spanish constitution is not exceptional in guaranteeing national sovereignty and territorial integrity of its borders, and is, in fact, in line with other Western democratic nations such as the United States, France, Italy and Germany. In a recent ruling on the hypothetical secession of Bavaria, for example, the German Constitutional Court indicated that the federal states are not sovereign but fall within the Federal Republic of Germany where questions of national sovereignty lie with all German people.

Perhaps the most tragic and lasting consequence of this political moment is the effect this is having on public opinion, eroding the idea of the state and the rule of law within a democratic framework that guarantees our individual rights and freedoms. After five years of continuous invective spewed by pro-independence politicians and commentators against the Spanish Constitution of 1978, this sort of depressing antisystemic discourse that would revile our hard-won democratic gains is not only becoming tolerated, but normalised.

It is bad enough that nationalist leaders have managed to normalise a disdain for the rules of our democratic, constitutional system. But what is worse is that they have managed to do it from within the very institutions of the system that they so scorn. To those who would constantly try to caricature Spain as being a nation of "low democratic quality", it is worth pointing to The Economist's Democracy Index, which in 2016 grouped Spain once again among "full democracies", akin to Germany or the United Kingdom.

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The philosopher Karl Popper described democracy's strength not so much as "the rule of the people" as "the rule of law", the restraining of power through constitutions and institutions that acted on behalf of the people. This is the essence of liberal democracy, settled in a system of reciprocal checks and balances designed to guarantee individual rights and freedoms and avoid the abuse of power, whether tyranny or simply overstepping one's authority.

Today in Catalonia we have a government presuming to be the only qualified judge of its own cause, deciding as they please which laws or judicial resolutions are applicable to them and their relatives, and which are not. If we were to accept this, it would also mean accepting, by extension, that everyone else in society has the same right, and could presumably take the law into their own hands. This would lead to nothing less than the wholesale destruction of the democratic state and the rule of law.

The nationalists, set on confrontation with Madrid, have no interest in exploring moderate or compromising solutions.

The pro-independence parties are starting to dispense with euphemisms, talking less and less about the non-existent "right to decide" and more about a right codified in international law, the "right to self-determination".

They face the problem that, as the former Secretary-General of the United Nations Ban Ki-moon has explained, the case of Catalonia does not fall within any of the circumstances provided by the UN for this right to apply. This right is limited to decolonisation processes and undemocratic regimes that do not respect the rule of law, subject to conditions established by the UN that have nothing to do with the situation in Catalonia.

The nationalists constantly invoke a supposed Catalan sovereignty before the War of the Spanish Succession (1701-1713), although at that time no peoples in the world could for one moment be considered sovereign.

This is because the concept of sovereignty vested in the people, ie, the concept of national sovereignty as opposed to the sovereignty of the king, did not begin to take hold in practice - at least in continental Europe - until the French Revolution (1789), and did not take shape specifically in Spain until the Courts of Cadiz (1812).

This is where the modern concept of nation stems from, that of a political nation as a collection of free men who are the subjects of rights and obligations, which is developing in Europe and across the Western world to this day and has become synonymous with citizenship.

This political nation, the nation state, the political community of Spain, is the only collective subject of sovereignty this country has known throughout its history. Since it resides in the people, sovereignty in Spain has always resided in the Spanish people as a whole and the Catalans have always played a key role in shaping this framework of coexistence and solidarity based on the unity of sovereignty.

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It would be senseless to break this shared history at the behest of a temporary or accidental opinion induced by the propaganda of the Catalan nationalist parties. Furthermore, it does not seem fair for the Catalans to assume the power unilaterally to put an end to that which we, the Spanish people as a whole, have put such an effort into building together.

Two of Spain's seven founding fathers, responsible for the country's current constitution, are of Catalan origin. This constitution is based on the indissoluble unity of the Spanish nation. Its ratification in 1978 was the result of a broad consensus across diverse parties, including the Catalan nationalists of Puigdemont's party, and received support from more than 90 percent of the Catalan voters in a referendum.

Nevertheless, the fact that our constitution does not contain intangibility clauses means that it can be changed. Thus it is not true that the nationalists have no choice but to put Catalan institutions outside the law. They could try to achieve their political aim through a reform that introduced the right to secession in the Spanish Constitution.

The problem is, they know that reform of our constitution, like that of any other, is a lengthy and expensive process that requires qualified parliamentary majorities, and that is precisely what the nationalists do not have. They do not even have a qualified majority in the Autonomous Parliament of Catalonia itself.

It is worth remembering that the nationalists are launching their challenge when they do not have the support of even half of Catalans. They know that the timing and political circumstances are against them; according to all the opinion polls, support for independence, which reached its peak at the end of 2014, has only decreased since then, coinciding with an improvement in citizens' perceptions of the economy.

With good reason, the rise in support for independence coincided at the time with the worst point of the economic crisis, which hit Spain particularly hard. Instead of recognising that their electoral growth had much to do with the uncertainty and social unrest resulting from the crisis, the separatists endeavoured to prove that this progress was because the Catalan people had finally understood their "manifest destiny": separation, because "Spain doesn't care about us", "They're robbing us", "They're treating us badly", "They don't let us vote". This is the creed the nationalists have been preaching for years, notwithstanding the ominous consequences of their discourse for coexistence between Catalans, and between them and the rest of the Spanish people.

The nationalists, set on confrontation with Madrid, have no interest in exploring moderate or compromising solutions. In order to hasten independence, they insist on presenting Catalonia and Spain as two opposing phenomena and they are not prepared to accept the plurality of Catalan society, of the citizens of Catalonia, the vast majority of whom feel as much Catalan as Spanish and need not renounce one or the other.

Nacho Martin Blanco is a journalist and political scientist. He writes regularly in the Spanish media, collaborating with newspapers such as El País. He is a Professor at the Abat Oliba CEU University of Barcelona.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.