Do what thou wilt shall be the whole of the Law.
NOTE: Written originally on December 28, 2009
i) The Human Soul is divided among the Tree of Life as the Neschamah, Ruach, and Nephesh.
ii) Neschamah corresponds to the Supernal Triangle which is the 3-in-1 of Jechidah, Chiah, and Neschamah; Ruach is the mind and the Nephesh includes both the body & physical world. 
iii) The Soul encompasses the whole Tree. 
iv) In the elemental schema, Spirit is assigned to the Supernal Triangle, the elements of Air/Fire/Water to the Mental Triangle, and Earth to the Physical pendant, i.e. Malkuth. Further, it is useful to consider Neschamah as inside rather than ‘above’ c.f. Kether as “center & secret of the sun”/Tiphareth, with Ruach & Nephesh about the core.
v) ‘Understanding’ is for the Neschamah, ‘Knowledge’ for the Ruach.
vi) ‘Knowledge’ is ‘lower knowledge’ of relations, facts, etc. and is subject to logic.
vii) Understanding is ‘higher knowledge’ or ‘gnosis’ which is supra-logical. This is the reason why Truth is expressed in paradox and said to be beyond Reason by virtually all mystics. 
viiii) Nephesh & Ruach (body & mind) block perception of Neschamah, but they are also the means of Manifestation of the Neschamah.
ix) The Ruach can only reach up to Da’ath which is a “false sephira.” This re-iterates the fact that truth is supra-rational/logical. 
x) The goal of Yoga is expressed Qabalistically with the number ‘0.’ 
xi) 0 or ‘Nothing’ is used instead of 1 or ‘Unity’ because 1 is opposed to & canceled out by -1. 0 therefore expresses the result of the union of opposites, and “Yoga means Union.” 
xii) Other numbers (and images) also express this same idea, yet “every number is infinite, there is no difference” in that they all “shadow forth the Ineffable” and Infinite. 
xiii) The unity is between seer and seen, subject and object, perceiver and perceived in consciousness. The ‘evil’ in this case (being relative to our particular task) is separation of any kind, primarily between self and environment/ego and the world/Me and thee. 
xiv) This is expressed symbolically as 0, as stated in (ix), as well as the Rose-Cross, cross in the circle, point in the circle, the hexagram, mother and father, and essentially any other symbol that is Two-in-One. This is sometimes called Three-in-One because the ‘Third’ is concealed in the Entire Image in one sense. 
 See Little Essays Toward Truth, “Man.” Neschamah encompasses Kether, Chokmah, and Binah; Ruach encompasses Chesed, Geburah, Tiphareth, Netzach, Hod, and Yesod; Nephesh encompasses Malkuth.
 Further: The glyph of Venus encompasses the Tree of Life like the Human Soul cf. (iii). Venus is the glyph of Love which, in its most abstract form, is unity between any two things. Qabalistically ‘Love’/Venus refers to the uniting principle between Chokmah & Binah or Father & Mother of the Supernal Triangle which is yet another Two-in-One symbol c.f. (xiii)
 See the “Mundaka Upanishad” on this idea of higher knowledge pertaining to Self-knowledge and lower knowledge pertaining to all things we think of knowledge like science, history, math, philosophy, logic, facts in general, etc.
 “Briefly, Truth is an idea of a supra-rational order, pertaining to Neschamah, not to Ruach.” See Little Essays Toward Truth, “Truth”
 See Crowley’s “Berashith”, 777, and Book of Thoth (Atu 0: Fool) on this point.
 See Eight Lectures on Yoga, Lecture 1.
 See Liber AL I:4 and see footnote 9 below.
 “There was the Door to which I found no Key; / There was the Veil through which I might not see: / Some little talk awhile of Me and Thee / There was–and then no more of Thee and Me.” –Omar Khayyam, The Rubaiyat.
 “If we in any way shadow forth the Ineffable, it must be by a degradation. Every symbol is a blasphemy against the Truth that it indicates. A painter to remind us of the sunset has no better material than dull ochre. So we need not be surprised if the Unity of Subject and Object in Consciousness which is Samadhi, the uniting of the Bride and the Lamb which is Heaven, the uniting of the Magus and the God which is Evocation, the uniting of the Man and his Holy Guardian Angel which is the seal upon the work of the Adeptus Minor, is symbolized by the geometrical unity of the circle and the square, the arithmetical unity of the 5 and the 6, and (for more universality of comprehension) the uniting of the Lingam and Yoni, the Cross and the Rose. For as in earth-life the sexual ecstasy is the loss of self in the Beloved, the creation of a third consciousness transcending its parents, which is again reflected into matter as a child; so, immeasurably higher, upon the Plane of Spirit, Subject and Object join to disappear, leaving a transcendent unity. This third is ecstasy and death; as above, so below.” -Aleister Crowley, “The Big Stick” in The Equinox I(04)
Love is the law, love under will.