When the Gods forged Creation they imbued everything with a spirit of its own, a soul so to speak. The trees, the bushes, serpents and birds, everything was imbued with a soul. Even the very earth and the mountains got spirits of their own, as did the winds, the rain and the storms. There are spirits of love and spirits of disease, spirits of hate and spirits of passion, and all of these spirits answer the calls of the gods, though the Gods concern themselves primarily with the more powerful spirits like Storm-spirits or Earth-Spirits.
Men does not need a love spirit to love, the wind does not need a spirit to blow, nor does the Mountain need a spirit at all, but these spirits are the very souls of nature, caretakers and guardians, keeping silent vigil but also possessing agendas of their own. Every living thing, plants, animals but not microscopic life forms such as bacteria, have their own soul. Stones, mountains, the sea and the winds have shared spirits of nature, invisible beings of essence which float through existence in accordance with the Grand Scheme of the Gods.
These souls are what keep creation alive. Without his soul a man cannot walk, nor do anything else for that matter, a tree would wither and die. The mountain would still stand and the winds would still blow, but a farmer’s prayer for rain would go unheard as the Gods no longer had any spirit to command for the task. If a wind-spirit died the winds in its region would become calmer, more dormant and feel dead. Freak storms born of a Spirits rage would no longer occur, nor would the benevolent intervention on the behalf of the Gods (or in rare instances on behalf of the spirit itself).
Binding a Spirit:
The Spirits are what keep things alive and are nexuses of white essence, the essence that unites the elements and imbues them with life. As such the spirits are powerful and all mages learn early that they are resources that can be harvested or harnessed to fuel their magic and magic creations. Lesser spirits, like those of mice, birds and the insects, provide little fuel, but normal spirits, those of men, dwarves and even elves prove to be powerful sources of energy which can be put to many uses. Rarely does a mage get the opportunity to ensnare powerful souls like those of mountains, the wind, and the sea or of love and hate, but if they do, they have incredible resources at hand, if they prove adept enough to properly wield them, for the manipulation of such souls of power is difficult at the best of times.
Spirits of lesser and normal magnitude are already bound to a certain shape and cannot take any other form. The Greater Spirits can and do take any shape they desire, provided it is not a shape that is an anathema to their existence. It is worth noting that when the spirits take a shape, they do not actually look identical to any member of that race or plant, but instead they take a form based upon the spirits knowledge of the shape they take, and additionally they retain the traits of their true selves. Thus if a wind spirit took the shape of a woman, it would seem unearthly beautiful, too perfect and its hair would be battered by winds, as gusts of wind stagger the area around the taken shape, even though the wind should be completely still in nearby locations. In some rare instances, a Greater Spirit might fall in love with, or even come to hate, an ordinary mortal. These are instances about which legends are forged and any mortal blessed (or cursed) in this manner have some pretty abnormal experiences in store.