Mercury is the agent of communications and messages. Thus he is an enormous force who governs all human interactions. His agency is can be used for positive or negative work depending on the intention of the user. Thus the same Mercury is the perception manager, the middleman, the media, the manipulative agent, the blackmailer, the medium or the meddler. The Pedantic Teacher, the Esoteric Preceptor, the Royal Ruler, the Emotional Comforter, the Fiery Warrior, the Strict Taskmaster, the Desirous Rahu and the Nebulous Ketu all need the Communicator to deliver their messages. Mercury is the only force who can interpret, analyse, read, speak, hear etc, so he is the only channel through which the other planetary forces can communicate to our Consciousness. But Mercury is not a passive telephone line of the chart. He has his own agenda too as he Controls communication.
If you have observed, it is quite impossible to find Mercury placed alone in a chart. Most commonly he is conjunct with Sun or Venus and of course other planets. If rarely he is alone, the owner of his sign will influence. Only very rarely when he is alone in Gemini or Virgo will he be completely neutral, though aspecting planets will always influence. He is quite eager to interact with other forces and can easily absorb their messages, add his agenda to them and then transmit it to the target audience.
When a message is created naturally its copy is created. Thus Mercury is also the agent of duplicates, twins and copies. Thus siblings, team-players, co-workers, are his agents. And generally such messages are delivered to the students, pupils, disciples and subordinates. Thus such recipients and groups are also in the domain of Mercury.
Mercury is like the ultimate filing clerk. Whatever he sees and experiences, he mentalizes it and rationalises, How can I organise it? He is always thinking of better ways to organise his perceptions so that he can extract the maximum learnings from it. The trick is to make him understand when to stop. Mercury has to be stopped when the maximum has been learnt, else he tends to file-re-file, organise-re-organise, analyse-re-analyse just for the sake of it, in a never-ending loop. This leads to mental trauma eventually. The Compulsive Calculator, limited by his past. Every experience will be analysed as repetitions of the past patterns. When confronted with something completely new, which cannot be fit in and filed properly, he feels insecure and shuts down. These two are the most important karmic lessons that Mercury has to learn, to stop over-analysing and allowing events to flow, without reducing them to data bits.
Mercury is the son of the Moon. Moon is basically the unfathomable human mind and Mercury represents that part of the mind which is logical, rational, accessed, articulate and available for interactions. And as a typical teenager who doesn’t get so well with his dad, Mercury tends to be quite immature, rough and his decisions are hasty and based on superficials rather than deep wisdom.You see, Mercury is not so different from your average teenager, impressionable, adaptable, argumentative, becomes a malefic when posted with malefics, needs his peer-group, needs guidance from his elders.
Whenever Mercury influences any sign and house, he brings in his typical behaviour there. The matters concerned with that house and sign will now be organised and filed. Communications in every which way, then discussions, arguments, criticisms, explanations and analyses. He is always into short term goals and the proverb ‘penny wise pound foolish’ is made for him. He will always utilise every opportunity for trading, marketing, advertising, loves meetings and conferences, especially where he can toss around ideas, talk and talk. However he has a high analytical ability, is mathematical, also good at grammar, can articulate complex thoughts and is excellent at verbal and written analysis. He can recognise repetitive patterns, is calculative and very good at information exchange. Mercury is a highly successful lawyer or a great doctor! But the Mercury machine is addicted to measuring, then what should be done with these measures, he does not know, he cannot judge the value of what he has measured, he is not wise. He can just compare it against some pre-decided standard and docket it.
So Mercury always needs to be guided by another force so as to actually learn and grow up. And generally he accompanies Surya, the source of genuine intelligence where he acts a messenger boy for the Ego or Divine intelligence. Also seen with Venus, where he helps out in setting the terms for balanced agreements and treasuries or in conveying esoteric knowledge.
Mercury gets exalted in Virgo, where he is the lord of his own house. He is free to express himself and if not provided direction by other planets, is a mechanical amoral force of unrestrained intelligence. He then becomes sort of a super-computer, continuously organising, categorising, planning with the data available to him, till his amorality catches up with him and he messes it up. In Virgo he gets ample information about services, debts, diseases, enemies, arguments, discussions etc which he analyses till he finds the best possible way to file them. A Data processor.. info in info out!
Mercury’s brilliant analytical powers however get drowned in the dreamy sign of Pisces. He also considers the pedantic and wise Jupiter to be his enemy. Pisces is the sign of feelings, visions, sub-conscious, no focus, vague impressions, perceptions and universal consciousness. And Mercury is lost in this, he loses his technical powers of focus, practicality, articulation, problem-solving, and becomes vague and inconsistent. Debilitated Mercury struggles with the messages he receives from the Pisces sign and ultimately fails to convey the mysticism of this rashi in analytical language. His logic limited vocabulary cannot express the intuition, contemplation and meditation of the Piscine influence. Mercury gives similar results when posted in the 12th house of the horoscope too. He is incapable of contemplation and meditation, remember he is an adolescent!
Thus Mercury the Commercial Agent, must always remain busy, talking and trading!