Why is Tlön the "tertiary" world?
Last night, I finished an anthology of phantastical short stories, of which Borges' Tlön, Uqbar, Orbis Tertius was the final piece. Presuming that the orbis tertius ("third world" or "tertiary world") of the title is an epithet for Tlön, I am wondering what particularly makes Tlön the tertiary, or third, world. Given the numerous philosophical allusions in the story, I am considering that perhaps this is a reference to the Fregean dictum Die Gedanken sind weder Dinge der Außenwelt noch Vorstellungen. Ein drittes Reich muss anerkannt werden. ("The thoughts are neither things of the external world, nor imaginations. A third world has to be recognized." - my translation; I have here translated "Reich" as "world", as this so happens to be the ubiquitous translation of the term used in translations of Karl Popper's similar theory, but a literal translation of "Reich" would be "empire" and an acceptable compromise would perhaps be "domain".) It cannot be a reference to the more famous use of the term by Karl Popper, as Popper's theories invoking the term were published in the 1970s, long after the publication of the short story. What seems to speak against the identification of the orbis tertius with the Fregean third world seems to me to be that, while it is certainly thought up (I do not know enough about Frege to make a distinction between what he considers thoughts and what he considers imaginations, and why the latter is not a subset of the former), Tlön is quite distinctly composed of imaginations, so it is not what Frege tries to sever from imaginations as belonging into the distinct kind of the third world.
But perhaps the ground for the name are instead found more within the story itself, which would be the reasoning that the world containing Uqbar is the "second world", an imagination relative to the "real world" (of course, the real world of the story is already an imagination relative to our real world), wherein Tlön exists as the "third world" relative to the real world of the narrator. Such conscious reference to multiple layers of fictional containment seems to fit in with Borges' character.
Does anyone have any remarks on the matter, other speculation or perhaps even well-grounded information?
