Four-ness of Hermes
"But although Mercurius, in many texts, is stated to be trinus et unus, this does not prevent him from sharing very strongly the quaternity of the lapis, with which he is essentially identical. He thus exemplifies that strange dilemma which is posed by the problem of three and four - the well-known axiom of Maria Prophetissa. There is a classical Hermes tetracephalus as well as the Hermes tricephalus. The ground plan of the Sabaean temple of Mercurius was a triangle inside a square. In the scholia to the "Tracteus aureus" the sign for Mercurius is a square inside a triangle surrounded by a circle (symbol of totality).
Jung, C.G., Alchemical Studies, p. 224
FOUR - A Book of Fours. The Four Elements of Earth, Water, Fire and Air in Eliphas Levi; The Four Continents in "Secret of Alchemy' links to the Prayers to the Four Elemental Beings in Levi.
Looking at both Eastern and Western religious representations, we cannot but note that the similarity of the auric structures - spherical and behind the head. In the Middle Ages of Europe we see the aura divided into four. We know that the number four is the practical, the concrete and subsequently that which has form, the plane of matter is often symbolized as a cube or square e.g. the Yellow Square of the Muladhara Chakra.
Zain says of the Number 4:
"In science it relates to all those laws which govern the effective use of energy; to those which govern what is produced by motion."
Note: 'Fourness' and The Stone, in: Pawel, Adam - search on FOUR.
FOUR - The Quaternary expresses through all groups of 4 - such as the Four Elements, the 4 Gates of the Mandala, the 4 Points of the Compass, the 4 Guardians of the 4 Gates etc. These numbers are obviously symmetrical.
See: PaRDeS, paradise,ais a cipher of the four levels