What is your opinion on the syncretism of gods in greco-roman mythology? I know "the Romans just copied the Greeks" joke goes around a lot and i don't agree with it entirely. but I've also seen an increase in people who say you cannot consider myths written by Romans to be a "valid source" for Greek gods. Which doesn't sound convincing to me because aren't a lot of Roman myths, especially about Olympians, found in Greek mythology as well? The same myth but with the Greek god replaced with their Roman counterpart and vice versa (because they were thought to be the one and the same by the Greek and Roman writers). These are my thoughts but I want to hear from someone who has actually studied this. Thank you!
i think that (religious) history is our interpretation of an innumerable amount of facts, statements, sources and factors, and that in every statement you mentioned, there is a grain of truth! they can exist simultaneously in our consideration of the roman pantheon, because 'Rome' lasted about a millennium across three continents with millions of people. but to be more specific and more general:
the cults of Rome predate any serious consideration of matching up Greek and Roman gods. a cult to a god on the Mons Albanus outside Rome and a triad of gods were worshiped on the Capitoline hill. They have Lares and Penates. Many of their festivals and rites are uniquely local and Roman. thus, we cannot talk about perfect copies.
however, Latin literature and thus mythology cannot in any considerable way be divorced from the Greek literary (epic) tradition. The Romans, once engaging with Magna Graecia, started their literature by translating Homer's epics: their first original epics in Latin are historical epics, more about legend than myth in the strict sense. Thus, the characters of the gods as literary constructs are, if not copies because of the external influence of cult/theology, at least fully based on Greek literary characterizations of the gods. I think it's important to make that distinction between cult and myth/literary tradition. this literary reception in turn trickled down into cult and roman theology. think of the myths about aeneas already in the iliad -> romans reading it -> romans founding cults to Venus Genetrix, mother of Rome.
then, Greece becomes a part of the empire: Greeks start learning/reading Latin: Cultural syncretism happens overall. Hell, even before that Greeks were worshiping the Egyptian Isis and Phrygian Magna Mater as if they were Demeter and Rhea. Why wouldn't Greeks also adapt things they find in Rome, if it suits them? (people often forget that it went both ways. Did you know ancient Greek had loanwords from Latin?)
what you will notice, however, is that Romans rarely use the Greek names for the gods and vice versa, but that, furthermore, their focus will always be on either Greece or Rome. the gods are tied to locality and especially the Romans believed in a national destiny: thus, even if a Roman is telling Greek myths, Juno's ultimate home will be the Capitoline (in the Aeneid, she very deliberately makes the jump from Carthage (as Tanit) to the Cap). The Romans also usually use 'heaven' rather than Olympus, since their gods cannot have their home in Greece.
important to note: all this is about time and place. Who is writing what where? naturally Vergil in the augustan age writing a propagandistic latin epic will use latin names and favour the Roman cults and their ideas. naturally Nonnus in fifth century Alexandria writing an epic in Greek will favour Dionysus and incorporate the myths that became widespread during Alexander the Great's Indian Campaign, but he also draws considerable inspiration from Ovid. mythology is accumulative: chronology and source criticism are important, since myths often have a clear source and purpose for being invented/circulated. Is pausanias an invalid source, simply because he was a Lydian, not Greek proper, travelling through Roman Greece? there IS no clear divide between Greek and Roman once you cross 146 BC! i think when discoursists talk about validity, they mean authenticity, thus searching for the earliest instance of a myth and calling it Greek. but that is about origin, not validity or truth. a myth, or its varying versions, has meaning in the context in which it appears no matter when/where/what. an earlier version does NOT have more significance, except in its OWN context.
TL;DR it's an impossible web to untangle, but there are some anchoring factors, such as the debt of Latin literature to the Greek literary tradition, the assumption that gods are both universal and highly localized if only for favouritism, and the fact that any cultural interaction is messy. Your biggest consideration is time and place: who is writing, in what language and in what place, and why?
recommendations for scholarship:
Feeney, the gods in epic, especially the chapters on naevius/ennius, vergil, and ovid
Versnel, coping with the gods
Larson, ancient Greek cults, especially the chapter STRANGERS AND INDIGENES: Latecomer and regional deities
i hope this satisfies your curiosity, don't hesitate to follow up if you want to know more!
