Did Alexander, post Siwah, really think himself a son of Zeus/Ammon? What about Phillip then? Did he start thinking that Philip wasn't his dad? Or you could have two fathers - human and non-human? How did that work in the ancient mind?
How to Become a Hero
First, we must address what “son of a god” meant to the Greeks.
Not sure what part of the globe the asker is from, but if its where the dominant religions are Islam or Christianity (or Judaism)—monotheistic religions with an emphasis on canon—that introduces automatic bias both about What Religion is For, and What It Means to Be Divine.
Even if you’re not personally religious, doesn’t matter. One doesn’t have to be religious to define “god” after the fashion of one’s larger culture.
Ancient Greek religion constructed divinity hierarchically, with levels ranging from the Great Gods down to nature spirits and “little divine things” or “personal spirits” (daimonēs…yes, the root word borrowed by the Early Church later for demons).
Within that hierarchy—or really between it and mortal humans—existed one category of the “special dead,” called an hērōs: literally “protector.” Yes, you guessed it; that means “hero.” Herakles is the quintessential hero: protector and civilizer.
But he DIED. That’s important. Yeah, yeah, he got made into a godlet later. He still DIED.
In myth, heroes are the demi-god children of mortal and immortal, but mortal themselves. A few, notably Herakles, later apotheosized, but most were immortalized as constellations (if at all). The rest went to that Great Consolation Prize Place: the Elysian Fields. It wasn’t boring like Hades, and they remembered their lives, but they’re still dead.
It’s critical to understand that when Alexander claims to be the son of Ammon-Zeus, that’s what he’s claiming. He both venerates and competes with Herakles, but it’s one thing to compete with Herakles—quite another to pretend to be on a level with Ouranic Olympians such as Zeus.
By the 4th century BCE (Alexander’s day), a progression in thinking about human access to heroic status had occurred. This came in concert with the rise of Mystery Cults that granted regular mortals access to the Elysian Fields, once reserved only for heroes.
As the name hērōs suggests, hero cult emerged to commemorate local figures believed to be progenitors and protectors of a community. Stories were told about them and their larger-than-life feats.* The local basileus (chieftain) usually claimed descent from them, just as they were believed to be the spawn of this or that deity. This connection to divinity justified the chieftain clan’s rule, and also conferred on them critical religious duties for protection of their people (continuing the role of hērōs). Some of these heroes, like Herakles and Theseus, became panhellenic, but it took time and often owed to military dominance and/or quirks of fate. All Greek city-states had shrines (heroöns) for dead heroes important to their community…but not necessarily important to other city-states.
With the rise of colonization, where, by definition, new colonies (apoikia) lacked a mythical founder, heroic cult was given instead to the new city’s founder (oikistēs), after his death. This follows from the notion of hērōs as protector and progenitor—except now it’s an historical person. While the Greeks certainly believed their heroes were real people, they belonged to the mists of time. City founders were a different matter, and so a little bridge was built between hero cult for mythic figures, and hero cult for real people.
Then in 422 BCE, something astonishing happened: a city’s oikistēs got booted in favor of a new city hero.
Specifically, the colony of Amphipolis replaced cult for their founder Hagnon with that for the Spartan general Brasidas, who’d fought with and for Amphipolis against their mother city’s desire to dominate them politically. Their mother city? Athens.
So yes, the battle was part of the Peloponnesian War, and Sparta’s grand strategy to deny timber to Athens for her fleets. Yet it served Amphipolis well, and Brasidas had been their protector. So, he became the city’s new hērōs, replacing Hagnon, and given cult--games and sacrifices--yearly. (Below: silver ossuary of Brasidas from Amphipolis Archaeological Museum)
But Brasidas was dead first. He (quite famously) was one of only seven Spartans to fall there, in contrast to c. 600 Athenians. (It was a pretty decisive Spartan victory.)
The next step involved heroic cult for a still-living person. Another Spartan received it: Lysandros (Lysander). Lysandros was an interesting guy, opportunistic and pretty full of himself. Plutarch would have us believe he intended to replace the traditional dual kingship of Sparta with one king elected on merit: himself, of course. He certainly had the ego, but we may doubt the scheme as convenient to defame his memory. In any case, after the Peloponnesian War, he returned Samos to its citizens, largely to spite Athens. But again, the Samians were grateful and took a remarkable step, awarding him hero cult during his lifetime, according to Duris. We might see this as the nascent emergence of ruler cult. Ironically, Lysandros may have got the idea from areas in the north, such as Macedon.
Macedon (like Sparta) still had kings, but their kings retained more political and military agency, not unlike their Late Iron Age counterparts, the basileis descended from mythic heroes. And indeed, the Argeads claimed descent from Herakles. The king also had important religious functions. Bill Greenwalt has written some interesting things on the roles of Argead kings pre-Philip, and I’ve talked a little about it prior in an entry on Alexander “playing the god”:
Playing Dress-up with Divinity
In any case, regardless of whether Lysandros was inspired by Macedon, Philip II of Macedon was apparently inspired by Lysandros. He had a 13th statue of himself carted into the Aigai theatre, along with the Olympian twelve, on the very morning of his murder. WOW. And depending on who you think is buried in Royal Tomb I at Vergina…well, there’s a big-ass hero shrine (heroön) contructed above almost on top of it (below). I think it difficult to know how much Philip’s divine performance was influenced by Argead tradition already in place, but claiming that sort of status while alive almost certainly had some precedent in Lysandros of Sparta.
All that sets Alexander in a properly Greek context. Not a Judeo-Christian one. By claiming to be the son of Ammon-Zeus, he isn’t some Macedonian Jesus. He’s not even displacing Philip as his father. He’s claiming—by dint of out-doing his father, and even his ancestor Herakles—to be worthy of heroic honors. Yes, in his own lifetime.
To complicate it further, all our surviving sources are late Hellenistic or Roman imperial, well after ruler cult had become entrenched. So, our sources talk about him from the perspective of semi-ossified divine pretentions of Hellenistic and Roman rulers…ideas that Alexander started. Where things begin and where they end up are rarely identical.
So yeah, I’m pretty sure Alexander did think he was a son of Zeus, but probably not literally so. Adoptionism and descent from are better ways of thinking of it. His own tychē (great fortune) and success indicated, in turn, great divine favor.
Arrian may say it best in his final lines of the Anabasis. Although not critical of divination and dreams (as the Latin Curtius, who calls them superstitio), Arrian tends to be rather sober. Yet he says:
For this reason, I do not believe that a man peerless among humankind would have been born without divine agency (7.30.2, trans. Brunt)