BARCELONA'S splendid new Museum of Modern Art is currently exhibiting a touring show called Art and Power. It is an appropriately overwhelming, and deeply depressing, demonstration of the use of sculpture and painting in the service of totalitarian ideologies.
You can admire the monumental muscles of Stalinist peasantry in the USSR, and the remarkable sight of St Teresa grasping the martyred souls of Spanish fascists, and passing them on up to Jesus in the heavens.
The fact that both works could have been created by the same rather clumsy hand is part of the point of the show. Inadvertently, however, this exhibition, in its particular incarnation in Barcelona, teaches another, and much more contemporary, lesson about cultural politics. A friend who tried to buy a catalogue was told that it is only available in the Catalan language.
This is the sort of thing that drives many ordinary, decent Spanish citizens apoplectic. The exhibition is a major European cultural event, supported with European money, and has already been seen in several other capitals, including London. However, in Spain, it will only be seen in Barcelona. But the Catalans have seen no need to provide a Spanish language catalogue for any citizens who travel to see the show, or, more to the point, who live in Catalonia and do not speak Catalan.
The Catalans argue that the only way to recuperate a minority language is to practise a policy of "immersion". This means that there is now an obligation on both residents and visitors to learn some Catalan if they want to be able to communicate in Catalonia.
This is a step which goes considerably beyond an anodyne bilingualism without some degree of coercion, the Catalans nationalists say, the dominant Spanish language will almost always be chosen whenever one person in the company cannot speak Catalan, leading to its marginalisation and ultimate extinction.
Since the public use of their language was virtually prohibited for 40 years under Franco, it is easy for an outsider to see the Catalan point of view. Those who spoke this rich and literary romance language in the street were often reprimanded by Francoists with insulting phrases like "Don't bark", "Speak Christian" and, most tellingly, "Speak the language of the empire".
But it is also easy to see the point of view of the Spaniard in the streets of Barcelona today, who now feels the victim of a reverse discrimination. He or she has probably nothing against Catalans speaking all the Catalan they like among themselves, but can't understand why they won't use Spanish just as readily.
At the root of this conflict lies a much bigger question is Catalonia really Spanish at all? Or is it a "stateless nation" which happens to be under the control of Madrid, but which might just as well have become entirely independent, had the cards of history fallen differently? The same question applies to the Basque Country, where separatism takes the very militant form of ETA's terrorism, and to Galicia.
This question looms large in the current negotiations to form a new Spanish government, after the inconclusive elections of March 3rd. Mr Jose Maria Aznar's Partido Popular (PP) needs the support of several minority nationalist and regionalist parties if he is to replace Mr Felipe Gonzalez as prime minister. Mr Jordi Pujol's Catalan nationalist coalition, CiU, holds the critical balance of power.
Mr Aznar's anxious attempts to woo Mr Pujol have become the butt of a great deal of humour. The PP is a right of centre party, an inheritor of Franco's strongly centralist policies, which has always campaigned stridently against minority nationalists. Moreover, Mr Aznar personally directed much invective against the way in which Mr Gonzalez had, allegedly, made concessions to Catalan nationalism in order to win Mr Pujol's support for his minority government in the previous parliament.
Now the boot is on the other foot. All the evidence is that Mr Aznar is offering Mr Pujol much more than Mr Gonzalez ever did. He is certainly willing to make major concessions in economic terms, ceding extra fiscal rights from Madrid to Mr Pujol's autonomous government, which already enjoys extensive local powers. And Catalan language policy, long the target of PP attacks, will not only be tolerated, but endorsed.
It is in the cultural and linguistic fields that Mr Aznar's U turns have appeared most comical. He recently told TV viewers in Catalonia that he regarded Catalan as one of the most perfect expressions of language, and that he liked to speak it himself among small groups of friends. All this is a far cry from last February, when Aznar used to applaud the PP's ritual chant Pujol, enano, hable castellano "Pujol, you dwarf, speak in Spanish." (Mr Pujol, as you will gather, is not a very tall man.)
Now, the joke goes, the PP slogan has changed to Pujol, guapero, hable como quiera "Pujol, you handsome lad, speak whatever language you like."
This is a serious business, however, with the negotiations for a new government dragging on inconclusively, and the Catalans seemingly demanding and getting more with every passing week. The 1978 Spanish Constitution tried to reconcile two opposing positions recognition of minority "nationalities", and respect for "the indissoluble unity" of the Spanish nation.
Mr Pujol would like Mr Aznar to go further, and recognise Catalonia as a "nation" in his opening speech to parliament. But, in that case, the national status of Spain itself comes into question. It would be a supreme irony if the Spanish right, which has always argued for the mystical unity of the Spanish nation, should be forced, for reasons of political expediency, to concede that Spain is, de facto, a federal state, and not a single nation at all.