The correspondence between the divine and the human parent is one that, for these reasons among others, is very deeply rooted in the human mind. In an advanced stage of culture it may find its most natural expression in the related concepts of an ultimate and an immediate creator respectively, but at a more primitive mental level it is usually brought into connection with the distinction between remoter ancestors and immediate parents. There can be no doubt that the most important aspects of the theory and practice of religion are very largely derived from, and influenced by, ancestor worship, even though they may not, as Herbert Spencer has contended[162], have entirely originated from this source. Granted the fundamental assumption of animism--the existence of an individual soul or spirit which is to some extent independent of the body and may survive bodily death--it becomes easy to attribute to one's dead parents or to one's remoter ancestors powers that exceed those of persons who are still alive. There is not, as in the case of the living, any obvious and well defined limit to their capacity, and it becomes possible therefore to displace freely on to them the exaggerated notions which it is no longer possible to hold with regard to parents who are still subject to the conditions of earthly existence. The tendency which thus arises is reinforced by the very general fear of the dead[163], which easily attributes to its objects an exaggerated power--especially for evil. The more remote the ancestors in time, the more easy does it become to assign to them a power which is manifestly superior to that of the living, though the ideas of the ancestors and of their power necessarily become at the same time more shadowy and vague. [Sidenote: Unsatisfying features of simple ancestor worship]