I know it when I see it

I think most people would say that a classic novel is 'classic' because it has universal themes and 'staying power.' Is determining whether the novel you're reading is a classic a case where the 'you know it when you see it' approach will suffice?

What makes this complicated is when is something a modern classic? Really, what I'm looking for is what makes a classic a 'modern classic'? Is there a set criteria? A set date? Do you take Penguin's or Everyman's definition of what constitutes a *modern* classic?

I actually used my library's databases to investigate a bit further, and came across an article* that identified a paradigm shift that began in 1950 in how writers treated their protagonists. They started using their protagonists in a way that was "made to serve the writer's assumption that the individual is forever trapped in his loneliness and psychic impotence." I'm not well-read enough to know if that is true, or even what that means, but it does support my hesitation to arbitrarily decide that books published after, say, 1970 belong on a modern classics list, and books published prior to that belong on a classics list.

From there I started looking at various timelines of literature theory, and got waaaaaay of track. But it does seem like 1945 is a common cutoff year. And that makes sense to me, what with the war and all.

I suppose I could go so far as to consult some books on literary history, to expand my search for an authoritative definition of a modern classic. But, not now. Now, I'm going to sign off and read a little bit more from Madame Bovary before going to bed.

*Sources:
Polzner, Walter. "Is Modern Literature Unique?" World & I 12.3 (1997): 320-338. MasterFILE Premier. EBSCOHost. Hennepin County Library, Minnesota. 15 May 2008. http://search.ebscohost.com/