Our entire existence in this universe is determined by the law of karma. According to that all-pervasive law we receive a subtle body, as well as physical body. Among them subtle body is of higher nature, as it is carries us from one physical body to another in the course of time, and everything that makes us incarnating again exists in that body (like programmed code).
“Based on Lagn and the Grahas, joining and departing from each other, the native’s good and bad effects are deducted.”(Brihat Parashara Hora Shastra, chapter 3, slokas 4-6)
We can understand our physical body more easily as it is much more tangible, but understanding subtle body is another story. If we understand and help our physical body (by medicine, yoga, ayurveda etc.) it can be very beneficial for us rest assured. But if we manage to understand subtle body at least to some extent, it has the potential of elevating our existence even beyond this short life.
For that we must first understand what is subtle body and how it manifests itself. According to Lord Krishna (as he told Arjuna in Bhagavat Gita):
bhoomiraaponalo vayuhu kham mano buddhireva cha |
ahankaara iteeyam me bhinnaa prakritirashtadhaa |
(Earth, water, fire, wind and space, along with mind, ego and intellect, in this manner, this is my eight-fold differentiated nature.)
Thereby we can infer that subtle body comprises ego, mind and intellect envelopes. Ego (we can also call it false ego, as ego is always false by nature) has to do with our desires, that come from our ignorance, as desires deriving from our false self-identity impel us to incarnate again. Ego can be associated with causal body, since it is the main cause of all desires.
Mind and intellect are also parts of subtle body, being other envelopes, but they act in a different manner. Mind as our capacity to perceive things, to feel and to experience emotions plays a role of an instrument that is needed in order to make it possible for us to experience whatever we want and need to. Intellect plays the same role, though it is different from the mind (and it is said in ancient texts that intellect is of higher nature) as it gives us ability to discern, judge, operate with abstract categories, deal with paradoxes and so on. This is an instrument of incomprehensible complexity.
So, how can we possibly know about our subtle body – what are the causes that make us go into the womb after death to be born again, and what are the instruments (mind and intellect) we have for fulfillment of our desires and satisfaction of ego ? I believe the best way to know yourself is spiritual practices (particularly meditation), but we can also get some important clues using ancient texts of Vedic astrology.
In Brihat Parashara Hora Shastra (chapter 3, s. 12-13) it is stated that Sūrya [the Sun] is the soul of all. Candr is the mind. Mangal is one’s strength. Budh is speech-giver, while Guru confers Knowledge and happiness. Śukr governs semen (potency), while Śani denotes grief.
From that statement we can deduce that the Sun (Surya) reflects the soul of all beings in this world, while the Moon represents mind. As knowledge and speech innately have to do with intellect, we can infer that Mercury and Jupiter naturally guide it.
Now going back to a subtle body I assume that the Sun can give us a clue regarding what causes us to reincarnate as, in my opinion, it reflects a causal body at least to some extent. It shows what a soul wants (and needs) to experience in this lifetime. Most likely it doesn’t show our ego; and here I’m willing to agree with the statement made in ancient text of Saravali (chapter 4, s. 1-2) that Rahu is ego.
Now we need to advert to more technical information. In order to see clues about causal body we have to examine the position of the Sun in birth horoscope: its position in main (d-1) chart (sign and house), in shastyamsha chart (d-60), in navamsa (d-9) and exmine its nakshatra and pada. Look at the sign placement to see how a soul wants to manifest in this world and house to see in what area of life this manifestation is likely to be experienced. By analyzing nakshatra and pada of the Sun, you can get further clues about the nature of causal body.
The same concepts can be applied in analysis of the Moon (mind). The sign and nakshatra of the Moon would show you how you tend to feel and experience emotions, while house placement hints at what area of life is likely to become the main focus of your mind and source of emotional waves. Nakshatra and pada are of utmost importance in this case. In the same manner you can see what your intellect is predisposed to, by looking at Jupiter and Mercury (I would say Mars also, as Mangal is related to logic) and assessing their strengths and weaknesses.
Of course it requires much time and contemplation, but if you draw on intuition and apply those concepts, there is a good chance you’ll get to know yourself better. And self-knowledge is invaluable.
Hope it was helpful and feel free to comment and discuss.