Spiritus, or Spirit, is the male life-giving energy. It penetrates and vivifies everything. It is the internal power of the Metals. The (seven) Metals are different manifestations of this life-energy; they stands for emotions. In man we have the individual spirit; in Nature it is the Spirit of the World, or Spiritus Mundi. Man's spirit and the Spirit of the World are intimately connected. The alchemist says that it tinges the body, or matter. This expression means that it penetrates the body/matter and gives it particular properties (like a color, hence 'tinging').

The Spirit emanates, or comes from the Divine Fountain (or essence), and acts as a mediator between the Divine and man/the world. But it is not separated from the physical world, it penetrates everything. When it comes from the Divine, it is compared to air or wind; also called the Breath. When it penetrates the physical it is likened to water, a fluid, or Mercurial Spirit, as mercury is a fluid metal. It fills the entire World, all space.

It is the life force, which has the ability to make everything perfect. It can remove the imperfections of man, and make him a perfect being. That is called the Great Work, the purification of man's life-force from its impurities. The more Spirit is condensed, concentrated, coagulated, the more stable the physical forms are, the more alive, and the more healthy.

Knowing this makes the often cryptic language of the alchemists more understandable. An example taken from The Book of Abraham the Jew, by Rabbi Abraham Eleazar, as part of his work of Uraltes chymisches Werk, from 1760:

For the Spirit of the Lord is unfathomable. It hovers in the Air, it signifies the winged serpent and permeates Man and all Creatures that are created in the Earth. The winged Serpent signifies the Spiritus Mundi Universalem [the Universal World Spirit], and permeates all things under the heavens. This is our Materia [Matter] which we prepare out of the Coagulated Air. This is the Spirit which is extracted out of the Dew, and with which we prepare our Salt. The lowest serpent however signifies our Materia, which is found everywhere; and is earthly as well as heavenly, for it is the true Terra Virginea et Adamica [Virgin and Adamic Earth].

Salt is the physical form which is created by the Spirit.

Spiritus, or Spiritus Mundi, is symbolized by the god Mercury, or Mercurius. Mercury is aerial in nature, and flies between the heavenly realms and the physical world. The philosophical Mercury in the alchemical texts is the universal medicine. It has the potential to cure everything, because in essence it comes from the Divine. From another point of view, Mercury is corporified in the center of the Earth. What this means is that the physical world contains the mercurial spirit. It is firmly embedded in it in order to create and vivify the physical forms. As such it is called the Prima Materia, or the First Matter that underlies all of creation.

The Soul, or Anima is the same life-giving energy but seen in its female aspect. The alchemists didn't make much difference between the two. The anima can be seen both as the soul of man, or a the Soul of the World, or Anima Mundi. The World Soul was seen as a pure ethereal spirit diffused throughout all nature, the divine essence that embraces and energizes all life in the universe. The World Soul animated and formed nature according to divine proportions.

Anton Josef Kirchweger wries in his Golden Chain of Homer, 1723, writes:

Nature comprehends the visible and invisible Creatures of the Whole universe. What we call Nature especially, is the universal fire or Anima Mundi, filling the whole system of the Universe, and therefore is a Universal Agent, omnipresent, and endowed with an unerring instinct, and manifests itself in fire and Light. It is the First creature of Divine Omnipotence.

In short, the alchemists believed that all creation was imbued with an identifiable life-force, variously designated world spirit (spiritus mundi), world soul (anima mundi), or sometimes universal spirit. Paracelsus called it an aerial nitre. This was the basis for the philosophical Great Work, but it was also present in the chemical or laboratory work, because the physical substances are permeated by this life-force. Some alchemists tried to isolate and analyze this spirit. Samuel Hahnemann, who gave birth to homeopathy, denied any link to or interest in alchemy, but his work is nevertheless very similar to the old alchemists like Paracelsus (who specialized in alchemical medicines). Most likely Hahnemann wanted to avoid any stigmata attached to the concept of alchemy that prevailed in a scientific age.

Below are some artful alchemical depictions of the Spiritus (Mundi) and Anima (Mundi).

Quinta essentia, by Leonhard Thurneisser zum Thurn, 1574

Leonard Thurneysser (1531–1595) was a scholar and miracle doctor at the court of Elector John George of Brandenburg, Germany. He wrote two alchemical books, Archidoxa in 1569, and Quinta essentia in 1570. Quinta essentia is primarily about alchemical medicines.

The left picture from the book show Mercurius as Spiritus Sulphur. The term sulphur was used as a male, fiery term (sulfur being very flammable), and can have different meanings. He is holding a cup which emits vapors, emphasizing his volatile nature.

The right picture is the Anima Mundi, as Anima Mercury. Sulfur and Mercury are the two male/female underlying qualities of all existence. Sulfur is the fiery, warm quality, Mercury is the watery, cool quality.

The Second Key from The Twelve Keys by Basilius Valentinus, taken from Tripus aureus, a compendium of alchemical works published by Michael Maier in 1618.

The identity of Basil Valentine is uncertain, and more than one author might have published under this name. The author(s) must have had a lot of chemical knowledge. The Twelve Keys is a typical alchemical text, but at times also very cryptic.

In this Second Key, we see a winged Mercury holding a caduceus in each hand, with the Mercury sign above him. To the left is a Sun and to the right a Moon. Under his feet are a set of wings. The wings are on the ground, thus signifying that the volatile Mercurial Spirit is fixed in the Earth/Body. The swords also are a symbol of Fixation. The same for the bird sitting (and not flying) on the sword.

Les Rudiments de la Philosophie naturelle, by Nicolas de Locques, 1665

A beautiful engraving from Nicolas de Locques who was the 'spagyric physician of his majesty' of king Louis IV. Les Rudiments de la Philosophie naturelle contains a description of all the operations to achieve the Great Work, and description of the different methods of distillation.

The text below the image reads Ut viuant flammas falsis extinguit in undis, accenditq udis coelestes ignibus ignes, or In order to live, he extinguishes the false flames in the waves, and kindles the moist fires of heavenly fires. The false flames in the waves are the lower emotions, while the heavenly fires are the higher feelings.

What we see here is the Spiritus Mundi as mercury and the Anima Mundi as Venus. They are joining their torches, as they are two aspects of one medium, the life-force. The union of opposites is also shown by putting the moon underneath the sun. Usually they are depicted left and right in an emblem. The triangle Venus is standing on is the sign for the element of Water, while the upward torches form an upward triangle, the symbol for the element of Fire; again showing of opposites. The flames of the torches are inside a glass vessel, symbol for the human body in which this all needs to take place.

Utriusque cosmi maioris, Vol I, by Robert Fludd, 1617

Robert Fludd, (1574–1637), was a prominent English Paracelsian physician with both scientific and many occult interests. He had the gift of putting the esoteric ideas of his time into beautiful illustrations. Utriusque cosmi maioris is an encyclopedic compendium blending medicine and alchemy with scientific studies of nature, memory, and the soul.

The image is titled Integra Natura Speculum Artisque imago, or The Whole(ness) of Nature reflected in the Mirror of Art. The top displays the typical cloud with the Hebrew name of God, YHVH, who is the origin of all creation below him, with the many divisions of the worlds. The naked woman is the Anima Mundi, positioned (chained) between the Earth she stands on and God above her. She mediates between the two. She is crowned with twelve stars, and has a moon on one breast and one on her vagina. This depiction also reminds us of the woman in the Apocalypse, a depiction sometimes used for the Virgin Mary, which in alchemical iconography also stands for the Anima Mundi. One of the breast of the woman is sprouting forth milk (the life-force) moistening the earth. In alchemical terms, this is called The Virgin's Milk (Lac Virginis). The monkey at her feet refers to the alchemist who needs to imitate Nature.

Atalanta Fugiens, by Michael Maier, 1618

Michael Maier (1568–1622) was a German alchemist, whose book Atalanta Fugiens contains many engravings illustrating a mythological motif with alchemical symbols.

The first picture bears the title Nutrix ejus terra est, or The Earth is his Nurse. Here the Earth is the Anima Mundi who nurses the alchemist. She provides the life-force for all living beings.

The second image shows the alchemist who follows Nature. The Anima Mundi is here presented as Nature who carries the flowers and the fruits (of labor). All the alchemist has to do is to follow her path. If you go against nature, or the life-force, then your work is doomed. The title is In Chymicis versanti Natura, Ratio, Experientia et lectio, sint Dux, scipio, perspicilia et lampas, or In Chemistry Nature, Reason, Experience and Reading must be the Guide, Staff, Spectacles and Lamp.

A Key to Physics and the Occult Sciences, by Ebenezer Sibly, 1796

The engraving is called Symbol of the Universal Spirit of Nature. Nature is depicted as a nude woman with the Mercurial sign above her. In the 18^th century, the interest in alchemy was already on the decline, but this book gives the still prevailing belief systems at that time. Nature was still seen as an Anima Mundi lying at the base of all creation. The different symbols (some are alchemical signs) and images are more a reflections of several esoteric concepts.