Jeff Russell

That's actually a very interesting question, in part because trying to answer it is very complicated, and I'm afraid I don't have a good, definite answer for you. Short version: my own take is that Odin is more-or-less the direct descendant of the Skyfather, which explains why He's the king of the Gods, but the Skyfather was/is not necessarily the Thunderer, and that His Hermes/Mercury-like characteristics are something the Norse Skyfather retained or gained that most other IE religions don't show.

Longer (possibly much longer) take: underlying this question is a deeper one about who/what the Gods are, what we can know about that, and what Their roles/titles/associations in myth have to do with that. I wrote an article exploring some of this, but my summary would be that I think much of the specific roles, characteristics, and attributes of the Gods are pieces of a mostly-culturally-determined "astral vehicle," leading to differences in ritual and the experience of even the same God, as well as obscuring how much historical changes to myth or cultural differences in ritual and iconography apply to the same God with new associations versus different Gods with similar roles, or what.

Okay, so what about the Skyfather/Thunderer specifically? We can be pretty sure the Indo-Europeans worshipped a sky deity whose name was something like *Dyeus Pater, and that that deity had something to do with rulership. We can also be pretty sure they had stories about a warrior God who wielded a holy blunt/chopping weapon (club/hammer/axe - basically just not a sword or spear), killed monsters, and had some link to the sky or Skyfather, and very likely to thunder. The trouble is these roles mix and match in different ways in different IE-derived religions. In India, you have Indra, who was a thunder-club-wielding warrior with big appetites, including sexually, who was (at times at least) the King of the Gods. On the other hand, you had the God Varuna, who had something to do with sovereignty and upholding divine law, but was also scary, magical, and associated with wild warriors. In Greece and Rome, obviously the Thunderer was unequivocally the King of the Gods, upholder of divine justice and guarantor of sovereignty, and had mighty appetites (very much so sexual ones), but the club-wielding, monster-killing warrior is his son and not particularly associated with Thunder. Then, of course, we have the Norse myths, where Odin is (maybe) the Skyfather, definitely king of the Gods, definitely associated with wild warriors, magic, and other "scary" stuff, is associated with upholding divine law and bestowing sovereignty, and has a number of generative sexual liasons, though He's usually not described as "lustier" than you'd expect for a powerful and confident ruler. The Thunderer is His son, a mighty warrior, kills monsters with gusto, upholds oaths specifically, and has big appetites (but apparently not inappropriate sexual ones), but isn't really associated with rulership at all.

(Incidentally, you may have noticed I've been a bit coy about referring to a "king of the Gods," in part because the role of "king" seems to have had some complicated history in the different Indo-European groups, sometimes more secular, sometimes more sacral, sometimes held by warriors, sometimes by priests, with some evidence for sacral kings and war-leaders at the same time, coming from different "castes," and some of this complicated picture may have been reflected in their myths).

On Tyr specifically, I don't buy the hypothesis that He was once the Skyfather who got demoted. My reasoning goes like this: the *Dyeus part of *Dyeus Pater, which is the etymological root of Tyr, Zeus, and Jupiter was also the etymological root of Latin deus "God." The demotion hypothesis basically goes "*Dyeus Pater got shortened to *Dyeus, which underwent sound change to become Tyr, but all along it was the same God, who changed in importance. The alternate hypothesis, which I find more convincing, is that Tyr's name came from the generic word for "God," maybe through some kind of taboo against saying His older "real" name. I'm not sure I've seen anyone else discuss this, but I suspect this is what's behind Snorri's discussion of how you can use "Tyr" in kennings for any male God - "Spear-Tyr" for Odin, "Hammer-Tyr" for Thor, and so forth. Snorri gives a kind of muddy explanation for why this might be, but I think it was a survival of the more generic use of the word, which was otherwise abandoned when the word stopped meaning "a God" and came to be better known as the proper name of one particular God. More substantively, Dumezil draws a lot of parallels between Indo-Iranic Mitra and Tyr, and you can see traces of his most famous myth in the Roman story of Mucius Scaevola sacrificing his right hand to demonstrate his loyalty and commitment to Rome, thereby disheartening a besieging enemy - which suggests that some version of Tyr's best-known myth is very old, but not necessarily associated with the Skyfather. Sadly, my pre-ordered copy of a new edition of a translation of Dumezil's Mitra-Varuna, which goes into all this in much more detail, keeps getting pushed back (I ordered it with some money I got last Christmas, and it's current predicted release date is now January 1st, 2025).

So, to put all of that together, here's my current take: the Indo-Europeans worshiped a "Sky Father" who was associated with sovereignty in a mystical/spiritual way ("the divine right to rule" or something like that), and as you might see thunderclouds as the children of the sky, they also worshipped the Skyfather's son, the Thunderer, a monster-killing warrior with tales told of him breaking important rules/laws, but somehow making amends (see Hercules's crimes and labors, Indra's violations and restoration, and maybe some others). They likely also worshiped a God associated with changed states of consciousness, inspired loquacity, and possibly psychopompic functions, who was likely also a tutelary figure for coming-of-age lords and warriors (that's a whole other chain of evidence, the best presentation of which I know is Kris Kershaw's The One-Eyed God). It's less clear if this third set of roles was believed to belong to the Sky Father or another God, but one way or another, the Norse worshipped a God who combined them, Odin. Also, for whatever reason, Thor seems to have lost the "warrior God does wrong and loses His power" myths found in most IE traditions. For what it's worth, I suspect the Thunderer being seen as the supreme king of the Gods might have been due to ancient Middle Eastern influence on the Greeks (Marduk and similar), which is why you ended up with the Skyfather wielding thunderbolts, and the monster-killing warrior with a non-thunderous club.

Sorry for going on at such length, but like I said, it's a thorny problem, and while the explanation I've given here makes sense to me, I've had to piece it together from a lot of different places, and it's far from definitive, and leaves a lot of more "theological" questions unanswered.

At any rate, hope you found it interesting and I'd love to hear any thoughts you have!
Jeff