NOTE:  This article has been slightly revised from its original 1983 version.

          The following Soul's Purpose Formula technique has been slightly modified from that first developed by Dr. Douglas Baker and taught to me by Judi Laws and Lynn Koiner of the Amethyst group in Washington, D.C., in the early 1980s.   This Formula is based on the principle set forth on page 17 of Alice Bailey's Esoteric Astrology that the ascendant of a horoscope is the key to "the spiritual goal and purpose of the immediate incarnation and of the immediate succeeding incarnations."   The second two elements of the Formula are based on the astrological principle of house cusp rulership. In constructing the Soul's Purpose Formula, only the esoteric rulerships, as given in Esoteric Astrology, are used:
 

The Formula is to be used only on charts calculated for exact birth times.   Solar or noon charts are meaningless when working with soul-level astrology.
          Among the modifications that I have introduced to the Soul's Purpose Formula are the following: (1) Planets in the first house are considered as part of the Formula; and (2) a planet up to eight degrees behind a house cusp is considered conjunct that cusp and affecting its house rather than the house in which it is technically found.   Modification number (2) can be applied with flexibility due to the inaccuracy of most birth times and the use of different house systems, and may thus be overridden by intuitive judgement.
         Planets conjunct any of the "soul's purpose rulers" are included in the Formula and considered as important as the rulers themselves.  The suggested orb for these conjunctions is about four degrees, but this orb may be decreased or increased depending upon intuitive judgement and possible complications due to the involvement of a planetary stellium.
         There are three elements to the Soul's Purpose Formula, each being separated by a large dot, which can be translated as "ruled by."  Instructions for determining each of these three elements are as follows:
 

First Element

          Rising sign and "asc," followed by any planet in the first house, along with the sign of this planet and "1" in parentheses.   Example:
 

Second Element

         Esoteric ruler of the rising sign, the sign of this esoteric ruler, and the house of this esoteric ruler, followed by any planet(s) within orb of conjunction of this esoteric ruler, preceded by the symbol for "conjunct", enclosed in parentheses.   If the sign on the cusp of this house is different from that of this second element esoteric ruler, place the cuspal sign within a large "C".  Example:
 

Third Element

          Esoteric ruler of the sign on the cusp of the house containing the rising sign ruler.  This will be either the esoteric ruler of the sign within the "C" or, in absence of the "C", the esoteric ruler of the sign in which the ascendant ruler is found.   As with the second element, any planets conjunct this third element ruler should then be placed in parentheses, preceded by the symbol for "conjunct," as explained previously.  Also as with the second element, if the sign on the cusp of this house differs from that of the third element ruler, place it within a "C".   Example:
 

          For further clarity, these first-, second-, and third-element examples are repeated in the following illustration:
 

*Time adjusted for Time Zone 5 from original LMT of 3:58 p.m.
   (birth data from Profiles of Women by Lois M. Rodden)
 

          The Soul's Purpose Formula is intended only as a guideline, or skeleton, for attempting to discern the soul-level purpose in a given incarnation.   Its symbols should be interpreted in the context of the totality of the birth chart and within the realm of the intuitive perception of the astrologer.   In the future, when the psychology of the Seven Rays becomes blended with the art/science of astrology, the interpretation of the Soul's Purpose Formula will also be qualified by the soul (and Monadic?) Rays of the native of the horoscope.
         The Soul's Purpose Formula, consisting of astrological glyphs, represents an abstraction of energies characteristic of the planes/dimensions which transcend normal human consciousness.   Because words tend to limit, or even distort, the abstract ideas which they attempt to convey, one verbal expression of a Formula is at best only a partial picture of the soul's purpose of the native.  For a more wholistic perspective, it is recommended that at least two, and preferably three, verbalizations of the astrological formula be rendered.   The combination of these two, three, or more interpretations will hopefully give a type of gestalt of the astrologer's viewpoint of the native's soul purpose.
         This astrological formula for describing a soul's purpose is (as is all of astrology) a fusion of language and art.   Differing from a mathematical formula in which there is a concrete, one-to-one correspondence between the symbols and what they signify, the Soul's Purpose Formula consists of symbols deriving from the plane of Buddhi, or intuition, where verbal concepts are left behind in favor of more refined, pervasive energies.   The interpretation of the Soul's Purpose Formula, then, perhaps represents astrology at its finest:  a bold attempt to bridge Buddhi with intellect by stepping down archetypal energies into verbal form.

         For an example of the use and interpretation of the Soul's Purpose Formula, please see How the Soul of William Blake Spoke through his Art.