Of all the planets in our Solar System, Mercury is the smallest and closest to the Sun, with an orbital period of about 88 Earth days that makes it the faster moving planet. As a quick moving celestial body, never more than 28 degrees from the Sun, it epitomizes the swift, light and scattered energy of Mercurius/Hermes, known as the fast-flying messenger of the Gods – although the symbolism of these two divinities is far more complex and interesting, as we will see – and is therefore associated with information and the means through which it’s conveyed.
Mercury is the natural ruler of Gemini and Virgo – which represent two different stages of emanation of its energy – and therefore also of the Third (Gemini) and Sixth (Virgo) Houses. The energy of this planet is neither masculine (like the Sun) nor Feminine (like the Moon), but androgynous and adaptable.
Mercury was already known to Sumerians and Babylonians, for whom it embodied the essence of Nabu, god of Writing. Nowadays, you’ll often see Mercury mentioned in Astrology as the planet that rules the trade, hence the usual recommendation not to sign any deal during its retrograde periods; it has to be observed that the development of writing itself, which occurred in these societies, was driven by pragmatic exigencies such as maintaining financial accounts, which may clear out this ambivalence of symbolism.
In the Greek World, this figure of celestial emissary is personified by Hermes, which incarnates most of the original attributes we recognize in the planet; he bridged the world of the mortals with that of the Divine and unseen. On one hand, there’s a “trickster” quality about the young Olympian God, on the other hand this part shared equal footing with another important side to his character – the psychopomp, escorting Souls into the underworld (the Greeks weren’t concerned about “afterlife” as much as about the chtonic, earthy destination of the Souls into the realm of Hades). We can recognize these two characterizations in the signs of Gemini (trickster Mercury who outwits the other Gods) and Virgo (psychopomp Mercury) respectively.
The latter is associated to the syncretic combination of the two gods Hermes and the Egyptian Thoth, which came to be worshipped as one in some regions. Both deities were psychopomps guiding Souls to the unseen dimension, with Thoth incarnating superior, initiatic stages of knowledge. The union of these two principles is personified by Hermes Trismegistus, patron of Alchemy and Hermeticism. So, while Mercury the Trickster is the ruler of youthful, fleeing and spirited Gemini, Mercury/Hermes Trismegistus is the ruler of analytical, methodical Virgo.
Roman playwright Plautus (c. 254 – 184 BC) is among the notable Latin intellectuals who exposed a connection between the Greek Hermes and the Roman God Mercurius, in his play Amphitryon. This play begins with a prologue given by the god Mercurius himself, in which he gives background information to the audience, speaking of himself as the patron of mercantile activities (mercimoniis) and then stating to retain the function of Hermes the Messenger God. In the fifth verse, Mercury also claims to exert his power both within and beyond the boundaries (peregrique et domi).
Therefore, Mercury as an Astrological principle lords over knowledge and information. Intellect, intelligence, reasoning power, communication, talking (Gemini), reading and writing (these two being typically associated with Virgo) all fall under its rulership as well as siblings, short journeys, primary education, the immediate environment of neighbours (Gemini), forms of communications such as telecommunications, phone and e-mail. All kinds of assessment of data, thinking patterns, reasoning, manual skills (Virgo) are Mercury’s domain.
Mercury in our Chart speaks about our style of communication and decision making, the way we pick up and process information, how we coordinate and make sense of the information we absorbed, what kind of intelligence we possess. In the physical body, Mercury is associated with the nervous system, arms and hands, and it’s also connected to the voice.
This planet also brings instability wherever it goes, so Mercury in a Chart will also offer insight into the area of the native’s Life where he or she experienced uncertainty, dynamism and unstableness.