In preparing the present volume, the writer has been actuated by a conscientious desire to deepen and vivify our faith in the Christian system of truth, by showing that it does not rest solely on a special class of facts, but upon all the facts of nature and humanity; that its authority does not repose alone on the peculiar and supernatural events which transpired in Palestine, but also on the still broader foundations of the ideas and laws of the reason, and the common wants and instinctive yearnings of the human heart. It is his conviction that the course and constitution of nature, the whole current of history, and the entire development of human thought in the ages anterior to the advent of the Redeemer centre in, and can only be interpreted by, the purpose of redemption. The method hitherto most prevalent, of treating the history of human thought as a series of isolated, disconnected, and lawless movements, without unity and purpose; and the practice of denouncing the religions and philosophies of the ancient world as inventions of satanic mischief, or as the capricious and wicked efforts of humanity to relegate itself from the bonds of allegiance to the One Supreme Lord and Lawgiver, have, in his judgment, been prejudicial to the interests of all truth, and especially injurious to the cause of Christianity. They betray an utter insensibility to the grand unities of nature and of thought, and a strange forgetfulness of that universal Providence which comprehends all nature and all history, and is yet so minute in its regards that it numbers the hairs on every human head, and takes note of every sparrow's fall, A juster method will lead us to regard the entire history of human thought as a development towards a specific end, and the providence of God as an all-embracing plan, which sweeps over all ages and all nations, and which, in its final consummation, will, through Christ, "gather together all things in one, both things which are in heaven and things which are on earth." The central and unifying thought of this volume is that the necessary ideas and laws of the reason, and the native instincts of the human heart, originally implanted by God, are the primal and germinal forces of history; and that these have been developed under conditions which were first ordained, and have been continually supervised by the providence of God. God is the Father of humanity, and he is also the Guide and Educator of our race. As "the offspring of God," humanity is not a bare, indeterminate potentiality, but a living energy, an active reason, having definite qualities, and inheriting fundamental principles and necessary ideas which constitute it "the image and likeness of God." And though it has suffered a moral lapse, and, in the exercise of its freedom, has become alienated from the life of God, yet God has never abandoned the human race. He still "magnifies man, and sets his heart upon him." "He visits him every morning, and tries him every moment." "The inspiration of the Almighty still gives him understanding." The illumination of the Divine Logos still "teacheth man knowledge." The Spirit of God still comes near to and touches with strong emotion every human heart. "God has never left himself without a witness" in any nation, or in any age. The providence of God has always guided the dispersions and migrations of the families of the earth, and presided over and directed the education of the race. "He has foreordained the times of each nation's existence, and fixed the geographical boundaries of their habitations, in order that they should seek the Lord, and feel after and find Him who is not far from any one of us." The religions of the ancient world were the painful effort of the human spirit to return to its true rest and centre--the struggle to "find Him" who is so intimately near to every human heart, and who has never ceased to be the want of the human race. The philosophies of the ancient world were the earnest effort of human reason to reconcile the finite and the infinite, the human and the Divine, the subject and God. An overruling Providence, which makes even the wrath of man to praise Him, took up all these sincere, though often mistaken, efforts into his own plan, and made them sub-serve the purpose of redemption. They aided in developing among the nations "the desire of salvation," and in preparing the world for the advent of the Son of God. The entire course and history of Divine providence, in every nation, and in every age, has been directed towards the one grand purpose of "reconciling all things to Himself." Christianity, as a comprehensive scheme of reconciliation, embracing "all things," can not, therefore, be properly studied apart from the ages of earnest thought, of profound inquiry, and of intense religious feeling which preceded it. To despise the religions of the ancient world, to sneer at the efforts and achievements of the old philosophers, or even to cut them off in thought from all relation to the plans and movements of that Providence which has cared for, and watched over, and pitied, and guided all the nations of the earth, is to refuse to comprehend Christianity itself.