If Apollo is the sun god, then why do the Greeks need Helios-- another sun god?
Many of us like Greek Mythology because of its simplicity and romance: each divinity has his or her own human personality, each divinity has his or her clear and well-defined territory in nature. Apollo is the god of the sun, Artemis is the goddess of the moon, and that's wonderful, because they are twin brother and sister. Isn't it lovely that the Greeks have made an analogy between a trait in the human family and the twin but different lights in the sky?
Fortunately or unfortunately, if you scratch underneath the surface of Greek Mythology it soon becomes hopelessly complicated. It's not just the scholarly love of argument that can create a whole conference on The Functions of Dionysus in Greek Myth and Religion. The gods are really that dense in meaning.
Apollo is no exception. From the 5th century BC, he began to be referred to (not often even then, as far as we can tell) as a sun god. But his early function in Greek religion had nothing to do with heavenly bodies. In fact, the earliest Greek myths we know betray little interest in the sky as a mine for characters in good stories. Apollo's famous sun-chariot with its flaming horses is a comparatively late invention.
Once the Greeks began to become infatuated with the astral religion of the Near East-- Alexander the Great brought east and west together in the 4th c. BC-- Apollo took on more of a role as sun god.
But from the beginning, the god Helios was the sun, and he restricted his behavior mostly to being a witness to events. His most famous appearance in Greek Mythology comes in the story of Persephone, when he is one of the only beings who sees Hades snatch away Persephone.
Apollo has a rich and wide field of activity: he is a musician, a mathematician, a prophet, a physician, an archer, a bringer of plague and healing, an unlucky lover, a beautiful young man-- and an opponent of the Greeks at Troy. Over his temple at Delphi, where his representative gave psychic responses to myriads of questions, the motto "Know thyself" was chiseled. Apollo was a limiter god above all. He made sure that all humans stayed within their own boundaries. "Know thyself" for Apollo had nothing to do with enlightenment. It had to do with knowing one's limitations.
In an earlier incarnation Apollo could have been a Semitic god by the name of Resep or Reshef. In the Bronze Age (at least from 1200 BC) the religions of the eastern Mediterranean area-- Turkey, Syria, Lebanon, Israel, and Egypt-- had a strong influence on the Greeks. Resep was based in coastal Syria and may have come west by way of Cyprus, as did Aphrodite. Resep was an archer, a warrior, a bringer of plague (he was a shooter of firebrands), and a god of the stag or male deer, as Apollo also was.
Plenty of other levels remain. But the bottom line is that the Greeks never envisioned Apollo as a sun god. Only when it became the "in" thing to have a sexy and fashionable sun god did Apollo get drafted.
With thanks to Walter Burkert (his book is in my list on the left-- buy it).
Photo at top: Vroma.org