In Vedic Astrology, almost in all English books, the nature of the planet and its inherent qualities and the strength of the planet is confused. The avastha of the planet (which dictates the strength) is confused with its ability to do good or bad in the horoscope. According to the ancient texts, the nature of the planet is divided into benefic and malefic. Benefic planets (Saumya grahas) are Moon, Mercury, Jupiter and Venus. These indicate favourable, positive and beneficial behaviours. On the other hand, Malefic planets (Kroora grahas) are Sun, Mars, Saturn, Rahu and Ketu. These planets indicate unfavourable, negative, destructive, fierce and aggressive behaviours.
Similarly, in a specific horoscope, the nature of the planet is modified (to a certain extent) by being the lord of a specific house, e.g., the trishadaay houses or the 8th and the 12th houses. The degree or the amount of the effect the planets can have is described by the strength of the planet.
Hindi books are very clear on the definitions of favourable (shubh) vs. unfavourable (ashubh) vs the avasthas of the planets – balavastha, vriddhavastha. They correctly mention that all planets when strong promote their general and particular significations. When there are weak, they fail to promote their significations. Weak Sun and Mars would fail to give aggression. The person would have a less aggressive disposition. A person with a weak Sun would be humble, and a person with a weak Mars would not take initiative and would stay away from competition. Similarly, during the dasha of a weak and afflicted ascendant lord, health will suffer.
There is only one English language book that I know of – Fundaments of Vedic Astrology by Shri Bepin Behari that gets it right. On page 148, the word disposition is used for exaltation, debilitation and moolatrikona. The strength is mentioned in page 126. In the book, Beneath a Vedic Sky: A Beginner’s Guide to the Astrology of Ancient India, Shri Levacy does not help the reader when he says on page 251 that “you will develop ability to merge these factors together.”
I believe the confusion arises because all the planets have both positive and negative qualities. The positive qualities are stimulated and accentuated when the planet is in mulatrikona, exaltation, etc. The negative qualities are accentuated when the planet is in neecha, badly placed etc. If we take an example of Saturn, a strong Saturn would make a person a loner. The person would be disciplined because his/her actions would be after due diligence and thinking. These qualities would work in a positive way. For a weak Saturn, the person would repel people. The person would not be able to make any decisions because the diligence and thinking would never end.
For this purpose, it is very important to learn how planets behave in a certain Rashi and then look at how they behave in a certain house. Let us take an example of a Taurus Lagna with Saturn in the 11th house. So, we will have to consider the following together:
Further, the strength of Saturn based on the following will indicate its capability to promote its general and particular significations:
These aspects must be merged in order to generate the right predictions.