Budha aka Mercury, the smallest and the closest graha to Surya (Sun). It rotates around the Sun in just 88 earth days, the quickest. It rises and sets with the Sun everyday due to the close proximity and is also hard to find with the naked eye due to the same reason. Thus it always stays in the same house or one house apart from the Sun (in the chart). It is a dry, solid metallic planet with the presence of more metal (iron) than Earth. Due to its composition it can withstand intense amount of heat. It's also shrinking gradually due to its core.
Lord Budha is the God of the Budha graha and is the son of Lord Chandra (Moon). Budha was born through the extramarital affair between Chandra and Tara, wife of Guru (Jupiter). It made Guru and rest of the devas wage a war against Chandra who joined hands with Shukracharya and the asuras to lead the war. But no one was winning the battle so finally they accepted each others’ mistakes and concluded that Budha has to learn from Guru. Lord Budha was an intelligent, witty, attractive young boy so Guru had no choice but to teach him everything despite his indifference. Budha learned from Guru and started living a life of his own. He married Ila and fathered King Pururava, the first King of Alia dynasty through which the legendary Pandavas and Kauravas of epic Mahabharata came into existence. Yes, Budha was the first one in the hereditary of Chandra (Chandravamsha) through which the Mahabharata started.
Budha is the youngest (prince) among grahas so he maintains friendship/neutrality with every graha except Chandra. Surya loved this quality of Budha so he made him his confidant and kept him close.
This is the image of Lord Budha riding a liophant (lion and elephant).
Combining the scientific and puranic evidences (mentioned above) shows that Budha represents buddhi (part of the mind) mainly. Intangible significations are knowledge, intelligence, witty, communication (incl. media), young, quick, duality, adaptation, blend, logic, analytical, attraction, language, breath, CNS, skin etc. Tangible significations can be friends, siblings and cousins (esp. younger), aunts and uncles, assistants, confidant etc. Lord Budha inherited some qualities of Chandra and Guru, hence representing the duality of life such as good vs bad, day vs night, male vs female etc. Even the third gender is represented by Mercury.
Budha, when its strong, makes one intelligent, witty, quick (in everything), changing/adapting, logical, practical, technical, judgemental, look young, multi-linguistic etc. Budha represents the duality and how it mingles (meeting point) to create a harmony in nature.
Due to its duality, Budha is said to be a neutral graha, as in representing no gender. It can act like a male/female, benefic/malefic based on its association. Budha matures at 32nd year, so your logical, practical decision making abilities are fully functional from that time. Also the numbers 5 and 24 are important.
1. Exalted in Virgo and debilitated in Pisces
2. Rules the signs Gemini and Virgo
3. Gets directional strength in the East (1st house)
4. Ruling direction is North
7. Rajassic graha
8. Associated colour is green
9. Most dependent graha (young boy/prince)
10. Ruling deity is Vishnu
11. Mercury represents prithvi (earth) and the body part is skin
Exaltation and Debilitation
Budha attains exaltation in the sign of Virgo. It is the place where Budha feels most powerful.
To better understand this lets imagine Budha (Mercury) as a living entity and think of his requirements:
Budha always wants to be close/next to Surya (The King) and it helps him since he has a solid body with a dry skin. He's good at assisting the King and conveying the messages of the King to the others (messenger). Albeit he has a family he doesn't care much since he's always with the King, so everyone calls him workaholic, emotionless, celibate, sober etc. but he considers himself practical. He says that his work as an assistant/messenger to the King is more important to the society than everything else. These qualities are enough to say that Virgo is the most empowering placement for Budha. It is right next to Leo (ruled by Sun). Virgo is a dry earth sign (barren land) and the natural 6th sign of service, daily routines, celibacy etc. It is also the sign of critical thinking, problem solving, logical, analytical and detail oriented skills. Its symbolism is a young princess helping and healing others which reflects the primary motto of Mercury. Mercury is the youngest (a prince) who solves others’ problems. This is how, Virgo reflects everything Mercury is intending to do in this material plane. Mercury wants to be friends with everyone, even turns enemies to friends (6th house Aquarius). He’s quick, meticulous and a precisionist, so he takes every task seriously and finishes it with utmost perfection. He thrives through communication like speaking, writing, orating, social media (Libra, Aquarius and Gemini are artha houses). He’s quick and resilient so his efforts bring sudden changes that lead to evolution (3th house Scorpio). He loves order and structure in everything (4th house Sagittarius).
On the other hand, Pisces is the debilitation sign of Mercury. It is the natural 12th sign of addiction such as alcoholism, drug abuse etc. which makes him weak and clumsy. Pisces also stands for isolation, dreams, abstract emotions so Mercury is tested here. He’s forced to be in the realm of nothingness, spirituality, emotional approach. He’s unable to make friends (12th house Aquarius). He becomes an enemy to the King (6th house Leo). His actions become slow and steady (3rd house Taurus). His love for order and structure gets wasted in just talking (4th house Gemini).
So this is how Pisces deprives Mercury of his requirements.
Note: I've written this exaltation/debilitation concept after years of observational research and contemplation.