Catalan situation is stirring up ghosts of Spain's troubled past
Nationalism is such a prickly question in Spain that the country's national anthem is only one of a handful in the world to have no words, or at least no words that are acceptable to everyone. The 'Marcha Real' (or 'Royal March') once had lyrics approved by General Francisco Franco, their fascistic overtones reflecting the nature of his dictatorship. But the anthem has been played without words since 1978 when Spain embraced democracy three years after the general's death.
It is impossible to observe what is currently happening in Spain - with the clash between Madrid and Catalans seeking independence triggering its most serious political crisis in years - without seeing ghosts of the country's past, and particularly the long decades of the Franco era.
"Espana una, grande y libre" (Spain, one, great and free) was the slogan of the Franco regime as it sought to centralise the country through authoritarianism after it emerged from a civil war so bloody a large part of its history remains unexplored.
The post-Franco democratic transition saw Spain carved into 17 autonomous regions but the question of how autonomous they should be has been fraught ever since.
While the 1978 constitution gave control of services including education and health to regional governments, ultimate power was vested in Madrid.
Several parts of Spain chafed under this set-up, and some chafed more than others, particularly the Basque region and Catalonia where the sense of regional identity is particularly strong and rooted in distinctive languages as well as history.
Grievances from the Franco era play a key role in shaping narratives in both regions, the resentment towards Madrid is partly rooted in those historical experiences and can sometimes take a disturbing turn.
I remember one elderly man who helped found ETA, the armed group that transformed the Basque push for autonomy into a violent campaign, telling me they would never forget what Franco had done to their region. Among other things, he claimed Franco had tried to "dilute the blood purity of the Basques" by resettling people from other parts of Spain there.
For many Catalan separatists, similar memories of the Franco years are key to their antipathy towards Castillian nationalism.
But just like not every Catalan is in favour of independence, not every Spaniard troubled by the separatist push shares the worldview of the protesters in Madrid recently filmed making arm salutes while singing Franco-ist anthems.
Among the many who do not fit the lazy categorisations employed by too many on all sides of the current debacle is a Spaniard I know who was born in Extremadura near the Portuguese border - historically one of the country's poorest regions - grew up in Madrid and later lived for several years in Barcelona as an adult. He is a filmmaker and his politics are of the left. Having made his home in several countries over the years, if anything he would describe himself as citizen of the world. Several members of his family died fighting Franco's side during the civil war, others were among the war prisoners used to carve out the massive Valle de los Caidos (Valley of The Fallen) memorial near Madrid where the general was eventually buried. I remember visiting the site with him some years ago and seeing how the monument is a place of pilgrimage for those still nostalgic for the Franco era while representing something very different and unsettling to others.
Nationalism leaves this Spaniard cold for all kinds of reasons, including his country's turbulent past, but what is happening in Catalonia also worries him.
The actions of police who used rubber bullets and batons to stop people voting in last Sunday's referendum shocked him, just as the Catalan insistence to hold the ballot despite Madrid banning it as unconstitutional concerned him.
"There is much politicking at play and few signs of politicians facing up to their responsibilities whether in Madrid or Barcelona," he says.
He's been arguing with Catalan friends. "Emotions are running too high on all sides, it has fed the extremes."
What he dreams of is a Spain united in its diversity, one where the appeal of hard-line nationalists - whether Castillian or regional - would gradually wear away.
But the question of a singular national identity continues to elude Spain decades after Franco tried to impose one through a dictatorship entwined with Catholicism that sought to erase regional languages and cultural diversity. Many argue it is an impossibility.
For now, Spanish Prime Minister Mariano Rajoy has offered all-party negotiations which raises the prospect of some kind of agreement that would give Catalonia more autonomy, but not independence.
The police violence of last weekend has fanned the hardline Catalan separatists, however, so a peaceful solution is not guaranteed. And watching closely will be separatist movements elsewhere in Spain and far beyond its borders.