It is only during the present century that the Texts of Taoism have begun to receive the attention which they deserve. Christianity was introduced into China by Nestorian missionaries in the seventh century; and from the Xi’an Monument, which was erected by their successors in 781, nearly 150 years after their first entrance, we perceive that they were as familiar with the books of Laozi and Chuang-tzŭ as with the Confucian literature of the empire, but that monument is the only memorial of them that remains. In the thirteenth century the Roman Catholic Church sent its earliest missionaries to China, but we hardly know anything of their literary labours.