So it isn’t likely to happen.
And now it is less likely to happen with E.U. Commission President José Manuel Barroso saying what we all knew already, which is that an independent Scotland would have to apply for E.U. membership, just like Iceland or Norway. The negotiations will not be easy, even through Madrid will likely agree to allow the application.
I am opposed to Scottish (or Catalan or Texan or Québécois or Regiomontano or Camba or whatever) independence because I am opposed in-general to secession from democratic states. First, secessionism generally requires a cramped nationalism that is too close to tribalism for comfort. Second, it smacks of democratic failure: you don’t like national policies, but instead of trying to build a majority to change them you pack up your marbles and leave. Finally, it is (albeit probably not the Scottish case) selfish, a way for richer people to dissolve their historic bonds of community with poorer ones.
I read the Crooked Timber thread. The positive arguments for smaller states boiled down to (1) We do not like the way that the U.K. votes as a whole, so screw it; or (2) nationalism, just because. (By that definition, I should be a huge proponent for the Republic of New York and New Jersey Only with the Annoying Bit of New York Removed and Maybe Horse Country Too.)
If there are unreconciliable historical wrongs in play, then I could be persuaded to support the partition of a notionally-democratic state. For concrete examples, see Ireland circa 1922, Algeria circa 1961, or Kosovo circa 2008. But those are extraordinary cases that involved a horrible combination of long-standing ethnic discrimination and very recent bloodshed. Moreover, electoral democracy in the modern sense was a recent arrival to all three mother states: the U.K. in 1918, France in 1958, and Serbia in 2000.*
Absent that, however, I say no. Secession should be off the table.
But I might be wrong to say no! Counterarguments very welcome.
* The Fourth Reform Act of 1918 introduced more-or-less universal suffrage to the U.K., although female suffrage remained limited until 1928. The French Constitution of 1958 granted full voting rights to all Muslim residents of the Algerian departments. Slobodan Milošević fell in 2000, after which Serbia (which remained notionally united with Montenegro until 2006) has held basically free elections.