But it should be recognized that the difficulties experienced by those who, in the period before World War I, attempted to arrive at a "definition" of the class position of clerical employees are somewhat the same as the difficulties one must today confront in defining the intermediate strata of modern employment.  These difficulties arise, in the last analysis, from the fact that classes, the class structure, and the social structure as a whole, are not fixed entities but rather ongoing processes, rich in change, transition, variation, and incapable of being encapsulated in formulas, no matter how analytically proper such formulas may be.  The analysis of this process requires an understanding of the internal relations and connections which serve as its motive power, so that its direction as a process may be understood.  Only secondarily does the problem arise of "defining" the place of particular elements in the process, and this problem cannot always be solved neatly and definitively, nor, it should be added, does science require that it must be so solved (282-283).