Animism

Animism is probably one of man's oldest beliefs along with Totemism and Naturism, from its earliest beginnings it was held that spirit existed in everything, that the world is profoundly alive. The trees, rocks, wind, rain, rivers, birds, thunder,  all natural objects and phenomena are alive and have vital essence and consciousness giving them the potential ability to communicate with other beings. Animism further attributes soul or spirit to abstract concepts such as words or metaphors in mythology. Consciousness or spirit is a quality of the entire universe and world, rather than the exclusive possession of humankind.

Varieties of animism can be found in the worldview of countless indigenous people from every geographical area and period of time, from paleolithic ages to the modern. Though animism is widely found in the religions of indigenous people, aspects and forms of it are found in Shinto, Hinduism, Buddhism and Pagan faiths to name a few. 

Throughout European history, many philosophers like Aristotle, contemplated the possibility that souls existed in animals and plants as well as people. There have been sharply divided and varied thoughts as to the original concepts of animism held by primitive peoples.

The nineteenth century anthropologist Edward Tylor (1832-1917) claimed that the origins of religion lay in animism, which he defined as a "belief in spirit beings". Tylor saw the origin of religion in individual psychology, he thought that in primitive humans the idea of religion arose from the notion of a soul which came from dreams. The soul was  transformed into a spirit being after death, leading to the development of ancestor and spirit cults. 
 "Primitive Culture" (1871) By Edward B. Tylor

 Tylor was later criticized by another British anthropologist Robert Ranulph Marett (1866-1943) who was convinced that primitive man had not developed the intellect to form such simplistic explanations as Tylor proposed. Marett suggested early religion was more emotional and intuitional in origin. He theorized that early man recognized some inanimate objects because they had some particular characteristic or behaved in some unusual way which mysteriously made them seem alive. He believed early man treated all animate objects as having a life and will of their own, but he argued that animism was preceded by an earlier form of belief, a magical "pre-animism" characterized by an impersonal force which Marett identified with the concept of mana. 
Marett's idea of mana was developed in The Threshold of Religion (1909), Anthropology (1912), and Psychology and Folklore (1920).

Alfred Irving Hallowell’s  (1892-1974)
In his essay Ojibwa Ontology, Behavior, and World View
Instead of discussing animism in terms of individual “souls” that can be cleanly separated from a “body,” Hallowell introduced the term “other-than-human persons” to denote those beings that the Ojibwa people of south-central Canada perceive to have the fundamental qualities of personhood, consciousness, will, and the ability to communicate with other persons. Persons can come from any class of things, a few examples, Hallowell cites instances of stones, shells, thunder and trees being treated as “persons” in this sense.
 
Graham Harvey (2005), in  "Animism: Respecting the Living World", defines animism with the view that the world is full of persons, only some of whom are humans. http://www.grahamharvey.org/