Consciousness and Activity of Planets
On the gross level, jeeva is the soul and sharira is the body. On the subtle level, jeeva can be considered as consciousness and sharira can be taken as activity.
How do we know the jeeva and sharira of a planet?
There are twelve rashis (signs) and twenty-seven nakshatras (constellations) in Hindu/Vedic astrology. The nine planets are deposited in any rashi and the corresponding nakshatras, which have planets as their lords. You can learn the details about rashis, names of nakshatras, nakshatra padas and the distribution of nakshatras and their padas in the rashis and their lordships in any basic book on Hindu/Vedic astrology.
Suppose a planet is in a particular nakshatra. The lord of that nakshatra will be the the jeeva of that planet. If the planet Guru (Jupiter) is in the nakshatra of Mangal (Mars), then Mangal will be the jeeva of Guru. Now we have to check which nakshtra the jeeva planet is deposited in and what is the lord of that nakshatra. Then that lord will be the sharira of the planet. Now we have seen that Mangal is the jeeva of Guru. If Mangal is in the Ketu (Dragon's Tail) nakshatra, then Ketu will be the sharira of Guru.
For example, if Guru is in the nakshatra of Guru that is its own nakshatra then Guru will be the jeeva of Guru. Normally Guru will be the sharira also, but here the rule for finding the sharira planet is slightly different. If the jeeva planet is in its own souse, then only the jeeva planet will be the sharira planet. If Guru is in its own nakshatra and also its own house, then only Guru will be jeeva and sharira also. For example, if Guru is in the the nakshatra of Pooravabhadra fourth pada, then Guru is in its own nakshatra and its own house Meena (Pisces). If Guru is in the house of some other planet, though in its own nakshatra, then the lord of that house will be sharira. For example, if Guru is in the nakshatra of Punarvasu third pada, it is in its own nakshatra. But it is not in its own house; it is in Midhuna (Gemini), the house of Budha (Mercury). Then Budha will be the sharira of Guru. If Guru is in the same Punarvasu nakshatra but in the fourth pada, it is Kataka (Cancer) in the house of Chandra (Moon), Then Chandra is the sharira of Guru.
In another example, consider Chandra in Makara (Capricorn) rashi in the nakshatra of Shravana. Then Chandra is in its own nakshatra so Chandra is the jeeva. But Chandra is not Sharira. Sharira planet is Shani (Saturn) since Chandra is in the house of Shani.
Jeeva for a planet is the lord of the nakshatra and the sharira for the planet is the lord of the nakshatra of jeeva or the lord of the house of the planet. What is the use of knowing the jeeva and sharira of the planets?
Jeeva is the consciousness and sharira is activity. A planet's consciousness is known from the characteristics of the jeeva planet and its activity is known from the characteristics of the sharira planet. If the characteristics of the jeeva and sharira planets are not in tune with the planet's nature and of a contradictory nature, the planet's consciousness and activity will clash and the planet will not be able to give its results in its own natural way.
Planets have a relationship between them as friend, enemy or neutral. In general, the planets Guru (Jupiter), Surya (Sun), Chandra (Moon) and Mangal (Mars) belong to one group and the planets Shani (Shani), Shukra (Venus), Budha (Mercury), Rahu (Dragon's head) and Ketu (Dragon's tail) belong to another group. The planets in the same group are friends with each other. The planets in one group are enemies to the planets in the other group. Of course, there are some exceptions and some are neutral. For example, for Surya, Guru is a friend and Shukra is the enemy. Similarly, for Shukra, Shani is the friend and Surya is the enemy. Planets have certain gunas or natures. The different gunas are Satwik, Rajasik and Tamasik, In general, Satwik is of pure nature, Rajasik is of restless nature and Tamasik is of dull or aggressive nature.
In general, the lordship of the first, second, fourth, fifth, seventh, ninth and tenth bhavas is good and lordships of the third, sixth, eighth, eleventh and twelfth bhavas is bad.
Now, let's see how the jeeva and sharira would affect the performance of a planet. Guru is a Satwik planet, that of pure nature. If it is in its own nakshatra and house, the jeeva and sharira also would be Guru. That means Guru will have the pure consciousness and its activity would also be pure in nature. There is no obstruction or contradiction in its consciousness and activity. Therefore, such a Guru would generally be able to discharge its duties smoothly without clashes /obstructions and would give whatever results it is supposed to give for the horoscope depending on its placement, lordship, associations, aspects etc.
If Guru is in its own nakshatra Visakha fourth pada in Vrischik (Scorpio) rashi, then the jeeva is Guru but the sharira is Mangal (lord of Vrischik). Here Mangal is a Tamasik planet, though a friend of Guru. Therefore the consciousness of Guru is of pure nature but the activity will be of aggressive nature. There is a little clash betweeen consciousness between consciousness and activity.
In such a situation the activity will not go in tune with the consciousness and the planet will not give its natural results to full extent. In addition if the lordships of jeeva and sharira planets for a particular lagna are also not in tune with the planet, the results will not come out fruitfully.
An example will explain the situation. There is a cake on the table which, from previous experience, your mouth wants to eat. But the consciounsness tells you not to do so because you are diabetic. But the hand, the Karmendriya, may or may not listen to the consciousness. If the jeeva and sharira are in tune with each other, you will not eat it, but if they are not in tune, you will eat it. This is an example of involuntary action against the wish of consciousness.
Another example has Guru's jeeva as Rahu and sharira is again Guru. That means Guru is the in the nakshatra of Rahu and Rahu is in the nakshatra of Guru. This is called nakshatra parivartana (exchange). This Guru's consciousness is Tamasik and the activity is of a pure nature. There is a clash between consciousness and activity, but this Guru although having an aggressive and materialistic consciousness, will try to act with purity considering all the pros and cons of the situation of the activity to be undertaken according to its role in the horoscope.
If Guru's jeeva is Shukra and sharira is Rahu, the consciousness is of a restless nature and on the activity side it is in the the hands of Tamasik Rahu, resulting in either rash or dull activity. This situation also will restrict Guru in showing its natural purity.
LORDSHIP OF JEEVA AND SHARIRA
The lordship of the jeeva and sharira planets will restrict or limit the consciousness and activity of the planets. For example, if Guru for Mesha (Aries) lagna is in Dhanur (Sagittarius) rashi in the Poorvashada nakshatra, it is in its own house and in the nakshatra of Shukra, its enemy. Shukra is the second and seventh lord for Mesha lagna and is malefic, so the jeeva of Guru is Shukra, which is against Guru. The consciousness of Guru becomes negative and Rajasik. If this Shukra is in Budha nakshatra, Budha is a friend to Shukra and an enemy to Guru. Budha is the third and sixth lord for Mesha lagna and is malefic, so the sharira of Guru is Budha, which against Guru. The activity of Guru is also restricted and obstructed. Such a Guru will not be able to give spiritual upliftment as expected.
If the same Guru is in the Uttarashada nakshatra, it will
be in nakshatra of Surya, the lord of fifth house for Mesha lagna and friend
of Guru. If this Surya is in the Chandra nakshatra, Chandra will be the
sharira of Guru. Here the situation of Guru is good with Surya as jeeva
as fifth lord and Chandra a sharira as fourth lord. Such a Guru can be
expected to give rise to spiritual progress.