The secretory activity of the pineal gland has only relatively recently become understood. Historically, its location deep in the brain suggested to philosophers that it possessed particular importance. This combination led to its being a "mystery" gland with myth, superstition and metaphysical theories surrounding its perceived function.
René Descartes, who dedicated much time to the study of the pineal gland, called it the "seat of the soul". He believed that it was the point of connection between the intellect and the body.This was in part because of his belief that it is unique in the anatomy of the human brain in being a structure not duplicated on the right and left sides. This observation is not true, however; under a microscope one finds the pineal gland is divided into two fine hemispheres. Another theory was that the pineal operated as a valve releasing fluids, thus the position taken during deep thought, with the head slightly down meeting the hand, was an allowance for the opening of these 'valves'.
The pineal gland is occasionally associated with the sixth chakra (also called Ajna or the third eye chakra in yoga) or sometimes the Seventh (Crown) chakra.[citation needed] It is believed by some to be a dormant organ that can be awakened to enable telepathic communication.[citation needed]
Writers such as Madame Blavatsky and Alice Bailey, considered early proponents of the new age movement, use the pineal-eye as a key element in their spiritual world-view...(see Alice Bailey: "A Treatise on White Magic", Madame Blavatsky: "The Secret Doctrine")
The notion of a 'pineal-eye' is also crucial to the philosophy of the seminal French writer Georges Bataille, which is analyzed at length by literary scholar Denis Hollier in his study Against Architecture.
"But the head has a hole in it. The pineal eye, the organ of not-knowing, is the undoing of science. If science thought up man, the pineal eye unthinks him, spends him extravagantly, makes him lose the reserve in which, at the summit, from his head position, he was guarding himself."
it has not been proved yet...

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I have read that the pineal gland is symbolized in ancient texts and artforms by their stylized head pieces. I have heard it referred to as the seat of the soul. I have read that since the ancients our pineal glands have been compromised. I have also read studies that flouride effects the pineal gland negatively and it is in almost all water everywhere.
My personal theory is that prayer or tapping into the spirit during meditation will strengthen the pineal gland- as it is the chemical resonance mechanism in our human body to interpret the spiritual. What made you ask this question?

The Pineal Gland; a telephone,or computer, available to a very repressed or depressed person . A means of communication to and from a higher form of being, a true entity, perhaps duel gendered in intelligence, and certainly possessing knowledge of future events, imparted to those trusted to know and realize the privilege granted to them by a supreme being, a higher form of evolution, not to be taken lightly. This experience could be short or ongoing and may begin in prayer and faith, or end quickly if the God Force finds you unworthy, turning you back to your own environment where you could fall even deeper into the underworld of lost souls. Be true and available to your God. Try to do no undue harm through your powers, granted to you.

Is there like, a more 'scientific' explination of the pineal gland?