Earlier chapters have tried to show that, as well as being related to doctrinal and theological considerations, the norms and teaching of the Church were also linked, and sometimes more closely, with its economic and political interests, both of which were necessarily involved in the establishment of God's rule on earth. But this level is clearly not the only one on which we must examine European kinship, for resistance and opposition may be as important as control and imposition.

In dealing with historical materials, one is often restricted to data which relate to the more formal aspects of a society. The sources, too, tend to consist of works of theology rather than of expressions of popular belief, to be concerned with the written law rather than with oral custom, with the ‘rules’ rather than the guidelines of practice, let alone the unannounced or unpublicised breaches of either. Literate societies produce sets of norms formulated in writing which may be very far removed from practice. These written norms can have a reference group whose members take them seriously, but there may be other elements in the population, who may be defined by class, ethnicity, sex or literacy, who work by different sets of norms, lying outside the realm in which le droit écrit is dominant. These alternative beliefs and practices cannot simply be regarded as variants on a common, written theme, for they may represent different interests, different ideologies, and may thus stand in marked opposition to the other mode.