An explosion of popular interest in the occult took place in the late 19th century in response to widespread disillusionment with orthodox religion, combined with a rejection of the equally dogmatic and faith-based doctrine of materialism. This gave rise to spiritualism on the popular level, as well as fueling interest in Madame Blavatsky's Theosophy. Another prominent occult group was the Order of the Golden Dawn. The Golden Dawn was heavily influenced by Blavatsky, and many of its initial members were Theosophists. Blavatsky tried to stop them from joining at first, but her members later persuaded her to allow it and membership in both societies was common.
The Golden Dawn made extensive use of astral projection and astral vision by performing visualization exercises involving the projection of "thought-rays" into various spheres of the Kabbalistic Tree of Life. Although the Golden Dawn required its members to sign an oath swearing never to undergo hypnosis, the intensively concentrated visualization exercises practiced by the Golden Dawn were in fact autohypnotic in the same manner as in scrying. In order for visualization techniques to work and actually impact the astral to bring about a magickal effect, single-pointed concentration, willpower and visualization have to be intensive enough to open a doorway to the subconscious mind. This is exactly what takes place in autohypnosis, although relatively few occult groups recognized this and instead simply developed aptitude in self-hypnosis through the disciplined practice of visualization exercises.
Any visual image can be used as a symbolic gateway into the astral dimensions, and the Golden Dawn recognized this. They employed colored eastern elemental symbols called Tattwas as focus points to create astral doorways. After staring at the brightly colored image on the card with intense concentration for a period of time, the eyes are then closed and the after-image is retained in the astral vision for as long as possible. The Golden Dawn's Samuel Mathers instructed initiates to: "Transfer the vital effort from the optic nerve to the mental perception, or thought-seeing as distinct from the seeing with the eye. Let one form of apprehension glide on into the other." A variant of the technique was staring at the symbols, then shifting gaze to blank field of color where the after-images generate opposite "flashing" colors, while the practitioner maintains and strengthens the images.
After-image retention exercises such as these are among the best means for activating astral sight and opening the Third Eye. The fixed and concentrated stare induces a light-medium hypnotic trance state and is incredibly effective in imprinting the symbol on the astral light. After some success in the retention of the after-images, the image is experimented with to widen into an astral gateway capable of being entered, usually in the Mind's Eye vision during initial experiments. At a more advanced stage the images can be projected into so that one experiences being physically present within a three-dimensional astral landscape. Mathers described the latter practice as follows: "Scenes, things, instead of being like pictures, have the third dimension, solidity; they stand out like bas-relief, then haut-relief, then you see as from a balloon, as it is said, by a bird's-eye view. You feel to go to the place, to descend upon it, to step out upon the scene, and to be an actor there."
The Golden Dawn also practiced astral projection into Tarot Card images and other occult symbols. The association of the Tarot trumps with the Hebrew alphabet and the Kabbalistic spheres and pathways was historically baseless, having been concocted in the same century entirely by Eliphas Levi. Levi, who realized that autohypnosis was the operative technique behind magick, liked to make up whatever he wanted and incorporate it into his own magickal system. However the Golden Dawn contributed so substantially to the popular association of the Tarot to the Kabbalistic Tree that the practice remains a mainstay of Western occultism. The lack of any valid historical association doesn't diminish the effectiveness of the correspondence, since its repeated use by thousands of scryers and astral travellers establishes the necessary connections on the astral dimensions, which are directly influenced by heavily concentrated mental and emotional energies. This highlights the fact that an occultist can literally make up any system they want and it will still work— provided they condition their minds to enter and maintain a sound state of hypnotic trance so that the intention of the rite imprints itself on the astral light.