The ancient seers based their Astrological conclusions on:
Observation – planets and nakshatras and their results.
Intuition – (primary means of knowledge)
Inference – based on certain cosmic principles/ laws.
Using these tools, they arrived at most of the arts and sciences like astrology, vastu etc. Knowledge of the cosmic principles was based on Intuition (in a way the inherent wisdom revealed in a transpersonal state of consciousness) by which they reasoned that form and essence are one . Intuition was based on the great cosmic law: As above – so below.
The 12 signs of the zodiac are arranged in the chart as below:
In the beginning, the Sun was the sole ruler of the zodiac and was placed in the sign of Leo. The Moon wanted a place in the heavens and when asked, the Sun placed it in the house next door (in the sign of Cancer). Mercury, the next planet to seek permission from the sun was given an area on the other side (In the sign Virgo) but being of a dual nature, Mercury approached the Moon too, asking for a slice of the heavens and was given the empty space next to the Moon (in the sign of Gemini). Mercury had set the trend now and the next planet to come along, Venus asked for and was given places both by the Sun and the Moon in the signs of Libra and Taurus. It was Mars turn, which by the same method, occupied the houses of Scorpio and Aries, followed by Jupiter who took over Sagittarius and Pisces. Finally it was the turn of Saturn, the slowest of the Planets who occupied the last two places left over -Aquarius and Capricorn. This story represents the Leadership of the signs and the Sidereal period. I.e. the time taken by the planets is exactly in this order astronomically.
In Vedic Astrology, the focus is on the nine grahas (the two luminaries, the five planets and the 2 nodes). The 9 principles of energy are nine aspects of consciousness. The physical planets are merely the “representations” of these Cosmic forces or forms of Consciousness. According to occult principles these 9 principles are at work throughout the universe, although their physical manifestations may vary.
No two charts can be similar since the inter-play of energies between the planets, signs and Nakshatras are innumerable.