An article in the July 2011 issue of Harper's Magazine asks "When is a Movie Great?" This article, by movie maven David Thomson, skirts the issue for the most part by declaring what isn't great about a given movie: "Hot on Friday, compost by Monday." And he brings up a few oldies that are undeniably great ones: The Birth of a Nation. The Nights Of the Hunter. Citizen Kane.
He does examine briefly the lure and pitfalls of declaring movie greatness: Technology (special effects) a la Avatar. Jaws, being released on a massive scale; thus seeming "greatness" is thrust on it. Publicity comparatives, i.e., The Social Network is the new Citizen Kane. Great acting, as in The King's Speech.
But, really, what does he believe constitutes cinematic greatness? What's great about Citizen Kane, for instance, that isn't about The King's Speech? He throws out the term "endurance," i.e., the test of time. And he indirectly isolates the nebulous term art.
I think I have a decent handle on greatness in print, but War and Peace in print doesn't equate to its cinematic weak sister. Still, some common ground exists between print and film: a story told in such a way that it transcends era. A tale that reaches into the depths of humanity's nature. A combination of scene, narrative, and setting.
The trouble with such declarations, regardless of medium, is that greatness is an intangible. We know when we're in the midst of it, but analyzing it, depicting it – that's another matter.