The pneumatic model of medicine is very well known throughout Arunia and probably represents the primary medical approach. It is certainly the one taught by the physicians and medici of the Avaunite order. Pneumatics is based upon the notion of a liquid or airy soul that inhabits the body. This soul or spirit is a physical fluid that permeates the body and particularly finds home in the veins by admixture with the blood. Pneuma is what gives blood its life-bearing property; living blood and tissue is suffused with pneuma, while dead tissue or spilled blood has lost its pneumatics.
Eyesight is essentially pneumatic: a pneuma of airy spirit is emitted from the eye in an invisible ray, stretching back to the brain, where the pneuma suffuses the imaginative portion. This is how evil things can enter the body through the gaze; spells, the power of medusae, cockatrice, etc.
Magic is also pneumatic. Those things that don't possess a pneuma must have a false pneuma. Indeed, the art of necromancy is believed primarily to be concerned with the manipulation of a true living pneuma or the creation of a false one.
Medicine, in dealing with the pneuma, seeks to balance the humoral makeup of this spirit fluid. This is primarily achieved through one of two methods: bleeding and feeding. Bleeding is intended to reduce the pneumatic composition of the body and thus allow fresh pneuma to replace it. Feeding is a way to introduce combinations of the four humors that will actually change the balance of the pneuma.
There are derangements purely of the mind that stem from imbalance of the pneuma. Illusions act upon the pneuma. Many things are believed to interact with it. It is the presence of pneuma in each troll's limb and finger that permits it to live on after it is detached from the body. Ghosts and other such spirits are all pneuma, insulated from dissolution by a powerful positive or negative plane connection.
The pneuma is what solves the problem of pieces and essentialism. If a man loses his hand, is he any less a man? No, because it is the pattern in his pneuma that suffuses every piece of him that makes him himself.
The pneumatic model is rarely challenged in the North. However, there is a place where pneumatics is in conflict with planar theory. A satisfying resolution has yet to be proposed. The conflict occurs where magicians examine the ethereal plane. It is clearly possible for a wizard to become ethereal, yet this state is also attributed to ghosts and spirits. Are they truly ethereal? If so, there would be no reason to resort to a pneumatic explanation for their presence. However, pneuma, being able to dissolve through all physical material, certainly is an attractive explanation for the power of ghosts and spirits to pass through walls and all other solid matter. The essential dichotomy is that planar theory suggests the possibility of the immaterial, while pneumatic theory is a materialist doctrine.