It appears to be characteristic of a very large number of societies that from time to time movements arise in opposition to the established religious institutions, offering either new means of attaining the benefits offered by the established religion or new interpretations of its dogmas. The leaders of these movements often claim to have received direct revelation from supernatural sources, and for that reason are frequently called prophets, though this name is of wider application, embracing also such persons as the Hebrew prophets, whose chief function appears to have been that of moral criticism, and also the givers of oracles who have a recognized place in some established systems. There is no reason to suppose that the movements of this kind which appear among non-European peoples subject to European rule form a class by themselves, but, owing to the circumstances in which ethnographic information has been collected, the bulk of this refers to subject peoples, and among such peoples religious movements are largely concerned with the relations between subject and ruler.