Elemental Theory
King Rulwyna and her mother Lolwyna were the first to lay out the formalization of alchemy still used today, dividing the composition of the material world up into the Four Primary Elements of Earth, Water, Air, and Fire, divided up by the combination of the Cardinal Pairs of Hot vs. Cool and Wet vs. Dry. Earth is Cool and Dry; Water is Cool and Wet; Air is Hot and Wet; and Fire is Hot and Dry. There are two further elements conceptualized by the alchemists and priests as being essential to the function of the world but not primarily a part of it. These are Vitriol and Quicksilver/Gygo, and are defined of as being Neither Hot nor Cool, Wet nor Dry and Both Hot and Cool, Wet and Dry; these contradictions make them outside the realm of the everyday material world, but of key importance to spiritual function and alchemy. However, which is the element of Neither and which is the element of Both is highly contested. Most alchemists believe that Vitriol - or at least the pure form - is Neither, which allows it to facilitate the transformation of one element to another, but some contest that it must be Both so that it can take and contribute attributes to materials. Research and argument continues, but is hampered by the fact that all agree that there has never been an isolation of a pure element.
Take for example the water one finds in a river or sea. It may seem pure, but if one boils it all away then residues of solid materials can be found - especially in seawater where there is a significant quantity of salt present. If one passes a piece of pottery through a flame it comes away blackened with soot from the flame, indicating the presence of Earth. While some materials are close to the pure forms of the elements, pure elements in of themselves are the workings of the divine. For those without access to the magic of the gods, this is perhaps a good thing, as vitriol can only be controlled by humans when in a suspension of water. Pure vitriol, unbound to a carrier, would surely be lethal to the human form as it rapidly catalyzed random change in everything it touched.
While esoteric ways to combine and manipulate the elements are known to the priests and alchemists, the everyday world has many obvious ways in which the elements interact. Take example the potter. Clay is a combination of Water and Earth, which allows the potter to shape it with ease. The application of Air however removes much of the water, setting the clay mostly in place, while the application of Fire sets it permanently. The application of certain powders adds in tiny solid carriers of Vitriol, which the Fire liberates to promote transformation of the clay into a glaze.
Elements and the Soul
All living things have at least one soul, the Heart Soul, with higher order beings having at least one Mind Soul. It has been speculated that higher order beings still can have more than one Heart and Mind Soul, and even hierarchies of souls and sub-souls. It has been determined that while the elements themselves are not gendered, when manifest in spirits they are. The Hot elements of Fire and Air are masculine - passionate and active but also fickle and explosive; the Cool elements of Water and Earth are feminine - supportive and deliberative but also passive and slower. In a properly balanced body all the elements are present in the correct mixture, with each of the Heart and Mind souls producing a Primary and Secondary element.
In a well balanced man, the Heart Soul is Primary Fire and Secondary Water, while the Mind Soul is Primary Air and Secondary Earth. This gives men exceptional strength and quickness of mind, but also makes them prone to impatience and an excess of emotion. In a well balanced woman, the Heart Soul is Primary Earth and Secondary Air, while the Mind Soul is Primary Water and Secondary Fire. This makes women calm, stable, and patient but also less immediately active. It must be noted that all people contain all elements, and thus men can be patient and women's tempers can boil over, it is simply that they are less prone to these behaviours and attitudes naturally.
It can of course be the case in the imperfect world of the material that imbalanced combinations can occur. The most common is that a soul produces the incorrect Secondary Element, leading to a spiritual imbalance. Excess Fire tends to produce nigh uncontrollable passions, excess Air a flightiness of the mind, excess Water a dullness of the emotions, and excess Earth an ossification of the mind. These imbalances can also shift the masculinity or femininity of a person, leading to a shift in attractions to those around them. The most extreme cases are where there is a mismatch in genders for the Heart and Mind Souls. In these cases the Heart Soul will produce a body of one gender while the Mind Soul will feel as another. In all cases of these imbalances, while it can produce discomfort and alienation from the community, the priests and shamans know the proper rituals to help better align the flows of energy, and in fact the excess can be used to work certain kinds of magic. While not universally accepted, it is believed that same sex attraction can as much be driven by a deficit of properly gendered energy as by an excess.
Third Souls
While the exact cause is hotly debated, there is undeniable proof of those with at least three souls. While these individuals can have disturbed lives, the excess of energy produced by an extra soul can also grant extraordinary physical and magical power. It has been suggested that the Third Soul is fact an artifact of the womb. Metaphysically, while the female body provides an abundance of Water and Earth for the flesh of a child to grow upon, there must also be a storage space for the child's souls within the mother's body in the time between conception and the flesh of the child becoming viable. As all men are descended from the First Mother, it stands to reason that they would also have the room within their Soul Structure for such a space, but it goes unused - some priests contest that this structure is in fact the testes of men, which contains the material for one soul of a child, the mother contributing the other, but as these scholars often argue with each other about which soul the mother contributes and which the father contributes they are not the majority opinion. It is thus posited that under the correct circumstances an additional soul may take up residence within this space, with many pointing to the difficulties of Third Soul individuals have in having children as being indicative of their metaphysical reproductive organs being otherwise occupied. Counter examples of Third Souls having children are usually in turn countered with the fact that twins exist and Third Souls also are often suspected as having four or more souls to account for their abilities, so perhaps the soul womb has sufficient room for up to four more souls.
It is believed that the physical presence of a womb makes women somewhat more likely to become Third Souls, explaining the existence of certain women among the ranks of the martial heroes of the People.
Demon Souls
The definition of a demon is a long standing argument among scholars and priests. While classically a demon is a spirit with no proper function in the material world, making its presence actively disharmonious, some consider the category to be a prior lack of understanding. While once believed to be caused by demonic activity, it is now felt that diseases of decay are caused by human interference into natural processes. Some in fact believe that demons are spirits of Vitriol or Quicksilver, performing tasks that do not make sense within the realm of the primary elements. With the dangers of Vitriol and many metals known if ingested or inhaled, it is believed that some examples of particularly badly affected spirit-touched individuals may not in fact be possession, but Third Souls who have a Vitriol or Quicksilver soul attached rather than a more traditional variation. While all agree that a Vitriol or Quicksilver Heart or Mind Soul would not result in a viable birth, in the Third Soul position survival may be possible, but the introduction of such esoteric elements would produce both exceptional spiritual capacity and a wildly divergent mind and/or body.
In recent years, with further insights from with careful handling of the spirit-touched, it is starting to become recognized that the rituals and spells for aiding those with imbalances of the Primary Elements are inadequate for those with a more esoteric Third Soul. Furthermore, since these elements are directly integrated into their soul structure, exorcism is not only useless but actively detrimental to their health. Determining the difference between demonic possession and an esoteric Third Soul remains an aggressively controversial point of contention between scholars, priests, and shamans.