From the time of Dionysius to the time of Plato, the cultures of the Mediterranean consented to this doctrine that claimed the existence of an order of ultimate reality which lies beyond apparent reality, and that this "paranormal" reality is accessible to the consciousness only when the "normal" routines of mental data processing are dislocated. It was Plato's pupil Aristotle who spoiled his master's game. Following upon Aristotle, Western philosophy became bifurcated. The philosophical temper of our civilization, being scientifically and technically oriented, is basically Aristotelian.
No such rational figure as Aristotle arose in the Orient to a position of equal eminence. Regardless of the reasons, Indian anatomists and zoologists, who were no doubt just as curious as the Greeks about the origins of life, and as skilled in dissection, did not feel compelled to set their disciplines up in opposition to metaphysics. Metaphysical philosophy and natural philosophy remained joined like Siamese twins. As a result, that discipline which became medicine in the West evolved into a system known as Kundilini Yoga in the Hindu culture. This was a system designed to produce in those who followed its teachings a condition of controlled "creative" madness.
In Western terms, Kundilini Yoga can be understood as a biological statement couched in the language of poetic metaphor. The system made a heroic attempt to join together the seeming disparate entities of body and mind. It is a very complicated doctrine; in oversimplified terms, the system encourages the practitioner to progress through the control of six stages, called chakras, of body-mind coordination. The sixth, the highest and most exalted state, is called the sahasrara.
The physiological site of this sixth chakra, the sahasrara, is located in the center of the forehead; it is symbolized by an eye--the so-called third eye, the inner eye, or the eye of the mind. When this eye is opened, a new and completely other dimension of reality is revealed to the practitioner of yoga. Western scholars when they first came upon this literature took the third eye to be an appropriately poetic metaphor and nothing else.
But in the middle of the nineteenth century, as the subcontinent of Australia and its surrounding territory came to be explored, a flurry of zoological interest centered upon a lizard native to the area, the tuatara (Sphenodon punctatum). This animal possessed, in addition to two perfectly ordinary eyes located on either side of its head, a third eye buried in the skull which was revealed through an aperture in the bone, covered by a transparent membrane, and surrounded by a rosette of scales. It was unmistakably a third eye, but upon dissection it proved to be nonfunctional. Though it still possessed the structure of a lens and retina, these were no longer in good working order; also lacking were appropriate neural connections to the brain. But the presence of this eye in the tuatara still poses a puzzle to present-day evolutionists, for almost all vertebrates possess a homologous structure in the center of their skulls. It is present in many fish, all reptiles, birds, and mammals (including humans). No functional role whatever could be imagined for this structure in humans, and it remained merely an anatomical curiosity until 1898, when Otto Heubner, a German physician, wrote a paper associating cancers of this organ with instances of precocious puberty in children. Heubner's observation was confirmed many times over in the intervening years and gave rise to a number of theories concerning the role of the pineal organ as a regulator of sexual maturity. Those who adhered to these theories considered the pineal to be a gland, but since no secretions could be isolated or identified as emanating from this organ, the theories remained unsubstantiated by clinical evidence.