If you believe in Democracy, then devolving powers to the people-- through referendums, or and something similar to the swiss cantonal assemblies, is of obvious necessity. I dont think a coherent and honest argument can be made for the ossified and large "representative" democracies we have today. In that regard, let Catalonia be its own country, Galicia, Navarre, and whoever else wants it. Split France, Germany, Italy, it doesnt really matter. Devolve the Government along the cultural or ethnic lines the people themselves want, devolve the powers of Government to the people. If you believe in Democracy and integration and peace and all that jazz, theres no reason to object to Catalonia seceding [even if you find it peculiar they'd want to]. Keeping people in bondage due to nationalistic sentiments is, frankly, the act of a barbarian and uncivilized populace.