The division of labor is a particular form of the differentiation of productive functions; just as the differentiation of productive functions is a particular form of social cooperation.… Social cooperation occurs whenever people work jointly to effect a particular end. Differentiation of function occurs when those who are cooperating perform qualitatively distinct tasks.… Division of labor is a special case of functional differentiation. It occurs whenever the various productive functions are performed in such a way that each person is assigned a task as his or her particular occupation. If jobs are rotated, then we have differentiation of function but not division of labor. This distinction is crucial.