Some alchemists list Separation as the fourth step for confecting the Philosophers’ Stone. First, fourth, ninth or wherever in the process, in truth, is not at issue. The so called list naming the steps toward making the Stone, as printed out in The Secret Teaching of All Ages, and again in The Most Holy Trinosophia, is for our linear way of thinking and perceiving. The sages constantly remind us that these steps are all but one operation, in one vessel, from one beginning to one end. Only misinformed miners in their physical laboratories would split intellectual hairs over which step ought to precede another. Those more seasoned and discerning know these number intimations are clues to the corresponding signs of the zodiac, and the Cube of Space, the skeletal blueprint of אין סוף, Ain Suph. This fourth step suggestively points to the fourth zodiacal sign, Cancer. So we might investigate that sign and its various elements for a deeper understanding of Separation. A common dictionary defines separation as: “To sort, part, divide or disperse (an assemblage, mass, compound, etc.), as into individual units or elements.”
Separation in the alchemical sense remains true to that objective. What alchemists attempt to separate is the essence of a matter from its apparent reality. They separate “the subtle from the gross.” Cancer is a cardinal watery sign. Our physical universe consists of what all philosophers through history have called their Water. Yet is this Water a Fire, and Air, and Earth. The entire world of the manifest is this 'fixation of the volatile' water, a coagulation of Universal Subconscious 'mind-matter.' Our apparent reality looks solid enough, however, and our physical world appears to the great masters and teachers of this Art as it does to us. They just know the truth of 'the matter.' They see through (perceive) the illusion from a developed inner awareness, and know that physical reality is comprised of vast spaces between the smallest physical particles. Maya is a constant vibration of sound and light. Spaces between the oceans of particulate are filled with the Fires of Virgin Sulphur, which alchemists also call Water. 'Solid' substances are amenable to change through an accomplished Will and Imagination working through the perfected physical body of an Adept. They succeed with keeping separate the real essence from the forms composed of the essence. Appearances do not deceive them. Solid forms do not impede their will and actions. Such is mastery of the alchemical step Separation.
The step is not a point, phase or period in time. Once we arrive Separation remains a permanent attitude. The Moon rules the sign Cancer. This hints Separation to be entirely a subconscious awareness. The sure method by which we accomplish this subconscious step is clearly suggested by the Qabalistic Cube of Space. The edge assigned to Cancer, the Hebrew letter Cheth, ח, and therefore to Separation, is East-Below. Separation then, consists of the faces East (Venus and Daleth), and Below (Moon again, and Gimel). For Separation to take hold in our awareness, we must consistently use the Venus Center function, our imagination, to impress upon subconsciousness the true fact that entire existence is nothing other than one homogeneous fluid substance, divided, cooled and finally frozen into the myriad objects perceived is this life. Subconsciousness will ultimately receive these true impressions and act upon them accordingly. Eventually these two centers, Venus (Vishudda Chakra) and Moon (Ajna Chakra), will work together through the renewed, enlightened personality to disintegrate and reintegrate any image held in concentration. This includes an Adept's own physical body. This is neither science fiction, nor fairly-tale fantasy. Personalities do this now and are living in this world with us currently. They are not aliens from an outer space galaxy far, far away. They are human beings who have completed the Great Work by consciously participating in their own evolution.
The planet Jupiter is exalted in Cancer and Separation. Jupiter, allocated the West face on the cube, symbolizes the whirling, mechanistic phantasmagoria of physical substance we call 'reality.' The substance mirage is the result of previous imagery from our collective, imperfect states of mind, hence the apparent chaotic conditions. The Hanged Man connects the East and West faces of the cube. He represents the attitude of the perfected Adept, and the means whereby such a consciousness congeals imagery into matter. The One-Self 'fixes the volatile' water through us. Hebrew letter Cheth means Fence or Field. Qabalists attribute personality to this letter. The actual fact is that the One Thing is everywhere at once. Personality is an illusionary, separating Fence. Sages know “that which is without...is as that which is within.” That which is both is One, Divine Substance. If we keep this true knowledge separate from that which appears real, the actual doing cannot be too far ahead. A final note. The two centers, Venus and Moon discussed above, added to the Saturn Center become 'Our Arsenic.' Reference this with ARSENIC, FIRE, WATER, AIR and EARTH.