That the answer to this must be in the negative is at last beginning to be generally admitted. Prof. Tiele, writing in 1897, was obliged to confess that “the new science of religions was in many quarters regarded with suspicion[8],” but Dr Jevons, when lecturing at Hartford in 1908, was able to say that “the time has happily gone by when the mere idea of comparing Christianity with any other religion would have been rejected with horror as treasonous and treacherous[9].” Yet it may be doubted whether the clouds have rolled completely away, and it is fairly certain that the many learned and able Catholic priests who have done so much to elucidate the origins and tendencies of ancient religions other than their own have until lately avoided the discussion of their relations with the earliest forms of Christianity. This is the more to be regretted, because they are in many cases peculiarly fitted for the investigation, and their acquaintance with the extra-Canonical Christian writers before Constantine, hitherto much neglected by Protestant theologians, would make their conclusions upon it especially valuable. Yet it is along these lines that future inquiry will probably advance; and if, as most of us believe, the Christian religion has outdistanced and survived all its early competitors because it was better fitted than they to its environment, it is of great importance even from the point of view of the most rigid orthodoxy, that we should have a clear conception of what that environment was. Fortunately the gaps in our knowledge have been in great measure filled by the work of Continental scholars outside the pale of the Catholic Church, who have been indefatigable of late years in discovering documents, editing texts, and publishing monuments which throw great light on the history of the religions which at the outset competed with Christianity for the favour of the Graeco-Roman world. A summary of these labours is one of the objects aimed at in the following pages.