While not a traditional Golden Dawn technique, the Middle Pillar ritual is rooted in the Hermetic Sciences taught by Golden Dawn based groups. Israel Regardie popularized the Middle Pillar ritual in one of his seminal works: The Middle Pillar.
Theory and Background [skip down to see the ritual itself]
The Middle Pillar, which many claim Regardie invented, is actually a small sliver of a larger procedure taught in several of the Golden Dawn based groups. The whole procedure is meant to build up the energies of the Tree of Life in the aura of the initiate.
Regardie chose to focus on a small section of the overall procedure, focusing on the central axis of the Tree of Life. The Tree of Life when represented in a two dimensional drawing consists of three pillars. The Pillar of Severity, the Black Pillar, consists of the sephiroth of Binah, Geburah and Hod. The Pillar of Mercy, the White Pillar, consists of the sephiroth of Chokmah, Chesed and Netzach. The Middle Pillar, which stands between the Pillars of Mercy and Severity, consists of Kether, Daath (a pseudo-sephirah), Tiphareth, Yesod and Malkuth.
The Middle Pillar is an excellent example of how a Golden Dawn based group teaches its members. The theory and practice of the Hermetic Sciences is taught in a series of steps. First the student learns of the pillars and sephiroth of the Tree of Life in the Grade of Neophyte, then learns of the divine names associated with the sephiroth in the Grade of Zelator. As the student proceeds though the Grades, they learn more stuff connected with the subject.
When they enter the Grade of Portal (the gateway between the Outer and Inner Orders), the student traditionally starts the task of consciously building up the Tree of Life in their own aura (the process is actually begin during the initiation rituals; Portal is when the student traditionally takes over the task). They will first just visualize white spheres of light and intone the divine names of the sephiroth; later they will add other symbolism and layers to the procedure.
Today, thanks to the work of Israel Regardie, the core of this procedure is well known in the occult community. The Middle Pillar ritual is now taught to Neophytes in many Golden Dawn Orders; other Orders, such as the BIORC, teach it in the Grade of Zelator. People who are not members of any Golden Dawn based Orders learn the technique from writers, such as Regardie, Chic Cicero, and Donald Michael Kraig.
The theory behind the procedure can be found in the belief that God created mankind in its image, and that the body of God is made up of divine virtues and energies. By building up a reflection of these energies in our own consciousness, we become more aware of God, and hasten our union with the divine.
The Ritual and its Practice
The Middle Pillar is visualized running down the central axis of the human body. In Golden Dawn based groups, the Pillar of Severity is to one's right and the Pillar of Mercy is to one's left-two dimensional diagrams of the Tree of Life are pictured as someone facing you (this is contrary to some philosophies and religions-the reconciling diagram is part of the Inner Order coursework).
Starting at a spot just above one's head, one pictures a sphere of white light (this is the Kether of the Tree that one is building in one's aura) and intones the divine name AHIH (Eh-hey-yah).
One then pictures a channel of light descending to one's throat. Picturing another sphere of light at the throat (the non-sephiroth Daath), one intones the divine name YHVH ELOHIM (Yod-Hey-Vav-Hey El-oh-heem).
Again one pictures a channel of light descending to their heart. Picturing another sphere of light centered at the heart (the sephiroth Tiphareth), one intones the divine name YHVH ELOAH VE-DAATH (Yod-Hey-Vav-Hey El-oh-ah Vah-Dah-ath).
Once again, one pictures of light descending to one's groin area. Again picturing a sphere of light (the sephiroth Yesod), one intones the divine name SHADDAI EL CHAI (Shah-dye El Khai).
Finally one pictures another channel of light descending to their feet, and another sphere of light forming there (the sephiroth of Malkuth) and intones the divine name ADONAI HA-ARETZ (Ah-doh-nye Hah-AH-retz).
That is the basic Middle Pillar ritual. One should practice it once a day, along with the twice daily practice of the Lesser Ritual of the Pentagram. By doing so, one helps build up the symbolism of the Tree of Life in their consciousness. These two rituals are the base from which one practices and expands many of the other procedures that the Golden Dawn uses.
For those outside of the Golden Dawn who desire contact with a Golden Dawn based group, it helps align your aura with the energies of the Golden Dawn current. Those of pagan, wiccan and new age traditions, it will help you empower any of the numerous techniques that laid the groundwork for the current occult revival.
As you gain more experience with the ritual, you can research and add the other layers and symbolism to the ritual as you advance in your understanding.
In the words of Israel Regardie: Enflame yourself with prayer.