MYTHOLOGY: "a traditional story, especially one concerning the early history of a people or explaining some natural or social phenomenon".
Alternately, you may choose to believe "myth" is "a widely held but false belief or idea." True or false, right, wrong, fiction or reality (historical) depends on the internal harmony of the amount of data you use to interpret mythology. Hince, the debate. The more data commanded, the more potential and probable the historical value. As Time goes forward, more elements will be proven true and/or historical or no. Again, it all depends on one's preference of approach. If a person believes all mythology is fictional mental psychological gymnastics of the imagination, so be it, until proven otherwise. If a person chooses to believe ALL mythology (or most of it) is/has a historical precedence, then so be it, until proven otherwise. It is all in the synthesis of the data as related to what we have established as "proven" history.
"History" only means:
"the study of past events, particularly in human affairs.";
"the whole series of past events connected with someone or something.";
"a continuous, typically chronological record of important or public events or of a particular trend or institution.";
"ate Middle English (also as a verb): via Latin from Greek historia
‘finding out, narrative, history, from histōr
‘learned, wise man’, from an Indo-European root shared by wit.".
"History" does not necessarily mean all past events and people must be "proven." take the ALIEN existence argument for instance. Most believe they exist without one thread of evidence, but "testimony."
The words "record", "study", "past events", "findings", "narrative", all infer the inclusion of "yet to be proved" (or disproved) elements.
"HISTORY" is a "story", and with the pun, History can be someone's belief or accepted ontology, "HIS-story" about the past as from traditional "oral" testimony.
"Historical Study" is all based on synthetic reasoning with a percentage of factual elements to back it up. The percentage of factual elements varies according to the prospects and methods of verification of the individual - this is why some history books are 95 pages verses 3000 pages. Mythology is like modern-day "Reporting". You have different colored news reports, some being "yellow Journalism." Other work hard to avoid normative reporting to favor "descriptive." No matter, History can never be 100% factual in every level of detail. The reporter will ALWAYS add "journalistic glue" to form his/her linear chain of people and happenings.
MYTHOLOGY: We Euhemerist Historicists approach mythology as stories about prehistoric events and people, observed by the contemporaries, and then orally handed down by the ancients' descendants, but with inevitable generational memory loss, imaginative compensational filler, and etc. [Uh?, I think the "fish" was 3 feet long and not 3 inches. Another Curator may reply: "NO!, our g.g.g. grandpaw said it was a "whale!"].
Now, the blatant error of the Modern is taking the minor [the sea creature] and negating the major elements. So, the Psychologist-mythologist tossed the baby out with the Bathwater.
MYTHOLOGY truly houses what the Psych says and sees because the "real" people in the myths lived, acted, and reacted humanly and so instilled such realities in the stories within mythology. The error with them is not the error with approaching mythology as a historian. The historical approach allows not just historical potentials but also the real psychological elements. So the basis of mythology is not just "fictional" imaginative "Old Wives' Tales." I think, maybe because Achilles and other people in the Troy Legends/Myths were pumped up to supernatural levels it may have been hard to believe the story. Now that we know Troy is a reality, persons like Achilles can be dumbed down to human levels.
The Historicist-Mythographer does this "beforehand" with all mythology- strip away the obvious fantastic and get down to what we understand about physical law.
MYTHOLOGY houses a lot of weird stuff- Super High technology for instance. 100+ years ago all this would be stripped away. Today we see such sciences as sonics, levitation, x-ray machines, glowing 'eternal' lamps, you name it. So, even in stripping away what we think is fantastic may one day be proven to be actual.
My personal argument is: "I believe and use the principle that the so-called "gods" are real people, deified Kings and other great persons of the past: ZEUS can be identified with Noah's son, SHEM., and etc. he is the Teutonic THOR. The example list runs as long as Genesis 10.