The distinctive feature of the doctrinal system of Christianity can thus be readily explained by a reference to the conditions of its origin. To investigate in detail, by the same method of historical inquiry, the causes which produced its separate dogmas, is the object of this essay. The origin of the earlier ones must be traced through the history of Judaism; the later ones were Pagan, but they were grafted on a Jewish stock. Starting from primary religious ideas, we have to examine the growth and modification of theological dogma. Our study, accordingly, will take us over the whole period of history. CHAPTER I. THE FOUNDATION OF MONOTHEISM. At the time of the birth of Christianity, only in one portion of the Roman world could a new and pure religion have arisen. The fusion of the empire had, by destroying their national basis, fatally weakened the Pagan religions; so far as real feeling was concerned, they had passed into the hands of the ignorant classes exclusively, and had lost the vitality in which alone the higher religious forces can germinate. Philosophies, resting on a common basis of contempt of the popular polytheism, were the refuge of the more enlightened. Between philosophers and those who still believed in the power of the ancient gods there existed a vast mass of people who had religious instincts with no sure means of satisfying them, ripe subjects for the new religion which they looked for but could not originate. At this time, throughout the Pagan world, a high and systematic morality could only be reared on an intellectual basis which destroyed sympathy with common men; in no part of it could have been developed the pure enthusiasm needed for the founding of a great religion.