Getae and Dacians? Are they the same? Or is this unknowable?

[Rumo]

I see you know much more detailed the Diodor writing. From what i found, Zalmoxis is compared there just with other two, Zarathustra of persians, and Moise/Moses of jews.

Yes, R?zvan, those too are part of that excursus, however not Zalmoxis is the central figure here, but Mneves and the Egyptian lawgivers.

the relation with godess Hestia, well, agree, is hard to know exactly if wasnt a mistake, or if wasnt just an interpretation of Diodor, of a autochtonous dacian godess (something like Mother Godess or so), which he related with Hestia of greco-roman world, dont know. However, i doubt that all writings about Zalmoxes and his teachings (like beliefes in imortality of dacians, or how they maked to be imortal) are based just on Herodotus writing. Dacians (and they religion) was well known by other writers/chronicars of ancient times, and i am sure if Herodotus writings wasnt real, they will said then another stuff about dacians.

I agree, it's hard to know if one particular account is truthful (though that is somewhat relative, truthful in what we need to know - i.e. the religious beliefs of Thracians and other barbarians, or truthful in what the author wanted to say or moreover, how his writings were understood in his time) or not, but we can decide to be convinced or incredulous if we're looking at things in perspective.
Zalmoxis is mentioned exclusively by Greek and Roman authors. The rich epigraphy of northern Balkans, though it reveals many gods and lesser deities (some native but some others imported from Graeco-Roman world, even from Anatolia or Egypt) lacks any mention of a god named Zalmoxis. When I'm saying 'lacks' I'm not considering notorious fakes like Sinaia lead tablets (where in a mixed Graeco-Cyrillic script his name reads Zamolscho, Zamolxiu, Zamolxsu, etc.) or CIL III 45* (here's in a 19th century catalog). If Zalmoxis was a true god (or deified ruler) of the 6-5th century Getae, he apparently was no more in the later centuries.
Also I believe Herodotus' account is among the few (if not the only) which might have genuine information about this Zalmoxis. Herodotus had two sources for this: a Greek legend that he was a slave of Pythagoras and a testimony about the religious practices of the Getae. For most later writers Zalmoxis was an exotic character, whose role was to make a point in a discourse about something else (like in the aforementioned excursus on lawgivers).

And i quote from memory (dont have time now for search the exact quote and translation), so its an aproximation, the writing of roman emperor Julian the Apostate about Dacians/Getae (he in fact quote there Traian, and i dont think he inspire just from Herodotus, or even if he knew what Herodotus writed about Getae/Dacians some centuries ago) : "I was only one who dared to go against the peoples north of Danube (Getae/Dacians), who was the most warlike/powerful peoples who ever lived, and this not just because of strenght of their bodies, but because of the teachings of their praised/blessed Zalmoxis, who told them that they dont die, just change their homes. So they like much more to go to a battle then make a trip/travel" (sorry if my translation isnt quite exact).

I guess your translation is good enough for our discussion, and, as you can see, we find here the same Herodotean topoi, augmented by later writers: the bravery of the Getae and their contempt for death, the cult of Zalmoxis involving human sacrifice etc.

Anyway, the point is that Zalmoxis and his teachings (regarding imortality for ex., or medical knowledges of his priests) to Dacians was know in greco-roman world, and wasnt based just on what Herodotus writed at some point, but was a reality.

The tradition of medical knowlege comes from Plato's Charmides. However the Thracian physician is just a literary character (the reference to Zalmoxis betrays the Herodotean source, this physician is one of the disciples of Zalmoxis making themselves immortals) whose intervention is instrumental in defining the Socratic teachings, in this case we have the sôphrosynê, the moderation, a Socratic knowledge and control of the self.

As well a reality was they share some common gods and believes with southern thracians (and even phrygians), and for sure they have a relation on language too (see the name "Daci-Dacus" presumly related with phrygian "daos" (with an even older indo-european root) which mean "wolf", an idea shared by Mircea Eliade too, which i consider the biggest authority in history of religion).

I don't know of any certain native god shared by these populations.
Speaking of Indo-European relations, the scholar Sorin Olteanu believes the ethnonyms 'Thracians' and 'Greeks' are cognates.