None, One & One Hundred Thousand (1926)
by Luigi Pirandello
None, One & One Hundred Thousand very much reads like a predecessor of later writers like Borges or Umberto Eco. Pirandello is obsessed with the "relativity" of social existence, to the point where Vitangelo Moscarda, the protagonist, ends the novel in an insane time. Pirandello wrote None, One & One Hundred Thousand over a period of 15 years, plus, and the language has the feel of something closer to poetry then conventional narrative fiction. Pirandello is not much for action, most of the text consists of Moscarda agonizing over several "every day" encounters as he realizes that everyone sees the world differently.
Put another way, None, One & One Hundred Thousand is "post-modernist" before such a thing existed, the fracture of narrative consistency being a hallmark of such books. It is hard to quantify the impact of translation on the quality of the prose, considering the poetic figures of speech and the fact that I read an early translation from the 1930s, I'm inclined to think that someone else could do better, but I'm not going to hunt down a more recent translation to find out.