Paganism, that is ethnic religions, can only be understood historically. They are the precipitate of a tribe's, a people's, group-experiences during its process of formation. They are passed on from generation to generation by way of tradition and are expressed either as customs, as mythology or as cult—the distinction between these three kinds of thoughts, words and deeds always remaining pretty vague. Moreover, all these group-expressions are in a constant flux; new experiences are added, modifying and perhaps logically contradicting, the previous forms of expression, possibly superseding them altogether.

Nothing, therefore, could be more misleading than wanting to explain a pagan ideology, an ethnic religion, in the same manner as that of a religion based on a depositum fidei, from which everything can be logically deduced. An ethnic religion never starts as a system, though in the end, at a certain point of intellectual development, systematisers arise that try to arrest the growth of amorphous agglomerations of group-experiences in the rigid moulds of a static ideology.