The Dioskouroi, meaning “Boys of Zeus”, Kastor and Polydeuces, are the twins of the Gemini constellation. Their tale is a mythological reminder that all human beings possess two natures. And this fact is easiest to see in those born under the sign of Gemini (May 21 – June 21).

Though they are twins, Polydeuces is the son of Zeus while Kastor is the son of Tyndareos, the king of Sparta. They are born to the king’s wife, Leda. The twins (called Castor and Pollux by the Romans) are inseparable in the womb and in life. Growing up as princes of Sparta, the twins distinguish themselves as gifted athletes. They take part in many adventures including the quest to win the Golden Fleece with Jason and the other Argonauts and the heroic Calydonian Boar hunt. But, before being able to ascend the Spartan throne, they die.

There are several versions of the story about their demise. In one version, Kastor and Polydeuces cause a family upheaval when they carry off and marry Hilaeira and Phoibe who were betrothed to their cousins, Idas and Lynkeus. In another recounting of the tale, a quarrel between the cousins erupts when Kastor and Polydeuces steal Idas’ and Lynkeus’ cattle. (In the ancient world cattle were considered to be a universal currency, equivalent to money). In the Apollodorus version of the tale, all four cousins steal a herd of cattle from Arcadia, and Idas, whose job it is to divide the cattle among the cousins, tricks Kastor and Polydeuces so that he (Idas) and his brother can keep the entire herd for themselves and drive them home to Messenia. Discovering the trick, Kastor and Polydeuces march against Messenia claiming the cattle and looting. Idas and Lynkeus find them with the herd and a fight breaks out. In the struggle Idas, Lynkeus and Kastor are killed. Only Polydeuces survives, because he, as the son of Zeus, is immortal.

After the battle Polydeuces finds Kastor near death and prays to his father to allow him to die with his brother; but Zeus offers his son a choice. Zeus offers Polydeuces an immortal life on Mount Olympus without his brother or, the possibility of sharing his immortality with his brother. This would mean the twins would dwell one day among the gods on Mount Olympus and the next, among the dead in the Underworld, alternating homes forever. Polydeuces chooses shared immortality.

The tale of Kastor and Polydeuces echoes the story of Mercury, Gemini’s ruler…. On the day Mercury (known as Hermes to the Greeks) is born, he steals Apollo’s herd of cattle, using trickery to conceal their whereabouts. He then kills a few cows to use their gut for a musical instrument he is making (a lyre). When he is caught, he tells many fibs, but finally confesses to the theft. Later, realizing how much Apollo wants his lyre, and wanting to keep the cattle for himself, Mercury talks Apollo into trading his herd for the instrument. (Note how Mercury kills Apollo’s cows for the gut used in the lyre – cleverly trading something that, in part, belongs to Apollo for something else that belongs to Apollo).* How appropriate that Mercury is known as the patron god of thieves and businessmen!

When Zeus hears about Mercury’s inventiveness and cunning he makes him his Herald, sure that the messenger god will be able to ‘fabricate something’ if and when it is needed. Mercury and the Dioskouroi are the only Olympians who can be found among both the gods and the dead. This detail is significant in that those born under the sign of Gemini display two distinctly different personalities; one that is light and breezy and the other – dark and somewhat downcast, like the places the twins inhabit.

People born under the sign Gemini share the dual nature of the twins and of their ruler, Mercury. Geminis possess Mercury’s trait of an active mind; they are also perceptive, versatile, inventive and witty. Like Mercury they enjoy playful deception and sometimes toy with the emotions of others for fun. They are able to keep a ‘cool head’ when pursuing their goals. This ability often involves overriding the feelings, and when it is exercised too often (or inappropriately) Geminis appear to be experimenting with their impact on others or they seem to be rather cold. The challenge for Geminis revolves around using their natural gifts to support an interaction with the world that is open, vital, intelligent and giving. Growth involves being aware of impulses that can lead to a life of disconnection from their human brethren and the deadening results that inevitably follow.

What human behaviors encourage a creative exchange of ideas, materials and energy (sounds like commerce!)? And what behaviors cut us off from one another and end the possibility of a vivifying exchange? Is this stealing that which belongs to the Sun, Apollo?

* From The Library of Apollodorus. Homer’s Hymn to Hermes tells a different tale about the creation of the lyre.