In Greek mythology the story of the birth of the god Hermes makes it sound as if he was originally mortal and that he somehow managed to bribe his way into becoming the twelfth [i.e. the last] of the Twelve Olympians, after appeasing his half-brother Apollon [Apollo] with a musical instrument, and sacrificing some of the cattle he had stolen from the same Apollon to the other eleven Olympians and to himself(!).

Hermes’ mother Maia was a daughter of the Titan Atlas. By some of this Titan's other daughters Zeus and Poseidon also had other sons, who all seem to have been born mortal. So there must have been something special about Maia herself or Hermes was at birth a mortal just like his half-brothers and cousins, and his father granted him immortality after he performed his amazing feats of theft on the day of his birth.

In the Homeric Hymn to Hermes, Apollon threatens to cast the baby Hermes into Tartaros "to rule over the little folk there," a threat which no other god but Zeus ever seems to make to any other person in Greek myth. Is this an indication of Hermes' mortality at this point?

Some Elaboration Notes for Your Consideration

By his wife Pleïone, Atlas had several other daughters apart from the seven Pleïades, but focusing on these seven for an elaboration of what I mean about the inconsistency of their children’s mortality states1, here is an illustration of their families.

Starting off with Maia as Number 1, if my estimation is correct, the birth order of the other 6 sisters is indicated by the importance of the gods with whom they consorted, so that Zeus had the 3 eldest, and Poseidon the next 2, while mortal kings married the 2 youngest.

I reckon that Sterope is older than (or, in some other sense, senior to) Merope because of the alternate tradition, mentioned by Plutarch and Hyginus, in which Sterope consorts with the god Ares (as opposed to marrying Ares’ mortal son Oinomaos; instead she becomes the mother of Oinomaos). I have therefore arranged them in this descending order in the illustration.

The proposed pattern would indicate that the younger the Pleïad is, the higher the chances that her offspring will be mortal, whether the father is immortal or not. (A similar phenomenon might be observable with Pleïone and her sisters, the other Okeanides [Oceanids].) This is one of a few ways I can think of in which the logic is supposed to work.

The son of [the eldest] Maia is immortal {born in this condition?}.

The sons of [the 2nd-born] Elektra seem to become [minor] deities eventually (perhaps all of them, after their death, like Iasion; or, alternatively, are Iasion’s 2 full-brothers born immortal, unlike him?).

The son of [the 4th-born] Kelaino perhaps is made into an immortal by his father. (In Apollodorus’ Bibliotheka, Poseidon takes Lykos to live on the Blessed Islands.)

All the children of the remaining sisters are mortal.

Assuming that Hermes was born immortal—in the illustration here the god has four [half-]brothers (who are also his maternal cousins)—why is none of these brothers (as far as I can tell) born immortal? Or are Iasion, Emathion, Dardanos and Lakedaimon (perhaps less-renowned?) immortals?2

Beyond that, he has 6 cousins (the children of Poseidon by either Kelaino or Alkyone) with virtually the same configuration of parentage (if we assume that Poseidon is just as immortal as Zeus and that Kelaino and Alkyone are just as immortal as Maia).

The simpler solution to all this is per the main Question: Hermes was not immortal at birth but performed some fancy footwork in order to attain his status as one of the highest gods of the universe [of Greek mythology]. This way there is no incongruity between his mortality condition and that of his closest brothers and cousins. I do acknowledge that such incongruity is in no way uncommon to Greek myths, and is part of what gives them nuance appeal, but I am quite interested in whether there is any logic internal to the narrative world of these myths to explain this apparent incongruity in particular.

I am not so much asking whether Hermes was a god or not when he was born. As with Hermes’ half-brother Zagreus3 (which is a perhaps much less “mainstream” instance [from rather more “fringe” Greek mythology]), there are in fact cases of mortal divinities in this mythology.

My question has more to do with whether Hermes could die when he was born. And if not, what is it that sets him apart from the other children of Pleïades who also had divine fathers (Great Zeus included) but who were themselves clearly mortal?

{This is an expanded version of a question that I have asked on Yahoo! Answers and on MythForum.}

1. The other daughters of Atlas and Pleïone (apart from the Pleïades, i.e.) are irrelevant to the topic since only one of them, namely Dione, has any children. Dione’s husband Tantalos and their children Pelops (who marries Hippodameia, the daughter of the Pleïad Sterope [see illustration]), Niobe and Broteas are all mortal. In Hyginus’ Fabulae, Dione’s brother Hyas is killed by some wild animal, so he obviously is mortal. In the same passage of the Fabulae, all the children of Atlas and Pleïone in general are described as mortal too. In that instance Hermes’ immortality is thus even more anomalous.

2. The daimon part of Lakedaimon’s name, for instance, might indicate something about [his] divinity. (Also I realise that Emathion and Iasion might not be brothers but rather merely 2 different names for the same character.)