Thus we arrive at the first criterium of religious beliefs. Undoubtedly there are secondary species within these two fundamental classes which, in their turn, are more or less incompatible with each other.[72] But the real characteristic of religious phenomena is that they always suppose a bipartite division of the whole universe, known and knowable, into two classes which embrace all that exists, but which radically exclude each other. Sacred things are those which the interdictions protect and isolate; profane things, those to which these interdictions are applied and which must remain at a distance from the first. Religious beliefs are the representations which express the nature of sacred things and the relations which they sustain, either with each other or with profane things. Finally, rites are the rules of conduct which prescribe how a man should comport himself in the presence of these sacred objects. When a certain number of sacred things sustain relations of co-ordination or subordination with each other in such a way as to form a system having a certain unity, but which is not comprised within any other system of the same sort, the totality of these beliefs and their corresponding rites constitutes a religion. From this definition it is seen that a religion is not necessarily contained within one sole and single idea, and does not proceed from one unique principle which, though varying according to the circumstances under which it is applied, is nevertheless at bottom always the same: it is rather a whole made up of distinct and relatively individualized parts. Each homogeneous group of sacred things, or even each sacred thing of some importance, constitutes a centre of organization about which gravitate a group of beliefs and rites, or a particular cult; there is no religion, howsoever unified it may be, which does not recognize a plurality of sacred things. Even Christianity, at least in its Catholic form, admits, in addition to the divine personality which, incidentally, is triple as well as one, the Virgin, angels, saints, souls of the dead, etc. Thus a religion cannot be reduced to one single cult generally, but father consists in a system of cults, each endowed with a certain autonomy. Also, this autonomy is variable. Sometimes they are arranged in a hierarchy, and subordinated to some predominating cult, into which they are finally absorbed; but sometimes, also, they are merely rearranged and united. The religion which we are going to study will furnish us with an example of just this latter sort of organization.