Somewhere in the neural network of the brain and the retina is spurred a phenomenon [phosphenes] that actuates inner sight, or luminous visions, and which may constitute the basis for an objective, physical framework for the visions encountered among religious adepts such as shamans and mystics... . Carl G. Jung, observing the transcultural character of the neurally stimulated phosphene shapes, pioneered the idea that certain archetypal symbols might originate in the personal experience of such luminous designs... . The almost visionary, later paintings, executed in an asylum, by Vincent van Gogh, exhibit phosphene patterns, as do many unskilled crayon drawings of youngsters between the ages of two and four years. As can be also expected, a large number of designs encountered in ancient and aboriginal cultures display phosphene-like characters.*

* Michael Ripinsky-Naxon, The Nature of Shamanism (Albany State University of New York Press, 1993), pp. 148-50.

Ripinsky-Naxon goes on to consider the archetypal symbol of the spiral specifically:

If we... recognize the spiral to be an archetypal pattern and its schematic representations as the labyrinth, then this conception may help elucidate our understanding of why this motif has been used to symbolize the unknown origin-point leading to the Hereafter, the cave, the tomb, and the womb of the Great Mother. The tomb, as has been noted, was constructed in resemblance of the body of the Great Mother, whose energy and procreative sexuality are conveyed through the element of the spiral.*

* Ibid., p. 150.

In this regard, note that Dick believed (see "If You Find This World Bad ...") that he sighted, through the vision of the Golden Rectangle, the goddess Aphrodite, or the sexual aspect of the Great Mother. As for the Importance of the Great Mother to Dick both philosophically and psychologically, the reader may consult his speech "The Android and the Human" in the present volume.