In 1954 Aldous Huxley's hugely influential book 'The Doors of Perception' was published. Huxley's title is taken from William Blake's 1793 book The Marriage of Heaven and Hell. In this Blake makes the following observation: ''''If the doors of perception were cleansed every thing would appear to man as it is, Infinite. For man has closed himself up, till he sees all things thro' narrow chinks of his cavern.'''' Opening the Doors of Perception will update Huxley's work and suggest process and procedures whereby man can, indeed, perceive reality in its true glory. The concept of 'the scale of transcendence' is analysed in great detail, and suggests that there is a scale of perceptions whereby the doors of perception are slowly opened and, bit by bit, they reveal the true nature of 'reality' as suggested by most esoteric teachings and mystic traditions. Most human beings perceive the doors as being securely closed. However there are occasions when the doors become slightly ajar and allow fleeting glimpses of what the Gnostics called 'The Pleroma'. For 'normal' people these glimpses are experienced during fleeting 'noetic' experiences. However for others the doors are prized upon by certain neurological processes starting with migraine and progressing through various 'altered-states' such as temporal lobe epilepsy, bi-polar syndrome, autism and finally, when the doors are fully open, schizophrenia.