What is animism?
The term animism applies to the belief that within all creatures and all objects there exists a soul or personality. It is thus a spiritual belief, and many scholars have offered the idea that animism was the first spiritual concept of humankind, and that it underlies all further religious thought.
Roughly speaking (for always there is scholarly dispute about such matters) animism is comprised of three fundamental forms. The first - sometimes called animatism - is belief that objects both natural and manufactured have spirits (trees, the sea, weapons, jewelry), and even volition. Second is belief in spirits that are not firmly connected to anything physical, i.e. ghosts, or even spirits of events such as thunder, wind, or dawn. Third is belief in and worship of the souls of people and animals, both the living and the dead, as in ancestor worship.
- Peter Kohler
From Encarta Online
A Christian perspective on animism - argumentative but instructive due to the contrasts drawn
Defined from the perspective of practicing pagans