166 THE AMERICAN JOURNAL OF SOCIOLOGY
also the founding of such an antithesis. The tri-unity as such appears to me to produce three sorts of typical group-forms, which on the one hand are not possible with two elements, on the other hand, in case of a number greater than three, are either likewise excluded, or are merely extended quantitatively without changing their form-type.
i. The unpartisan and the mediator. It is a highly effective sociological fact that the common relationshipof isolated elements to a potentiality existing outside of themselves produces a unifi- cation between them beginning with the league of states which is formed for defense against a common enemy, and extending to the "invisible church," which composes all believers into a unity, through the like relation of all to the one God. This society-constructing mediation of a third element is, however, to be treated in a later connection. For the third element has here such a distance, so far as the two others are concerned, that a real sociological reciprocity which embraces the three elements in a unity is not at hand. We have rather configurations of twos, since either the relation of those who act together is in question sociologically, or that which exists between them as a unity, on the one hand, and the center of interests in contrast with them, on the other hand. At this point, however, the ques- tion is concerning three elements so close to each other, or so approaching each other, that they permanently or temporarily constitute a group.
In the most significant case of bipartite combinations, namely, monogamous marriage, the child or the children, as a third element, may often exercise the function of holding the whole together. In the case of many nature peoples, the mar- riage is only considered actually complete or as indissoluble when a child is born. The ground for this rests, of course, in the value which the child has for the man, and in his inclination, sanc- tioned by statute or custom, to disown a childless wife. The actual result, however, is that this third additional element really for the first time closes the circle by binding the two others together. This may occur in two forms. Either the existence of the third element immediately produces or strength-
