Founder, and commissioned in His name to teach and sanctify mankind; possessing the essential features of visibility, indefectibility, and infallibility; characterized by the distinctive marks of unity, holiness, catholicity, and apostolicity. These notes of the true Church of Christ are then applied as criteria to the various rival Christian denominations of the present day, with the result that they are found fully exemplified in the Roman Catholic Church alone. With the supplementary exposition of the primacy and infallibility of the Pope, and of the rule of faith, the work of apologetics is brought to its fitting close. It is true that some apologists see fit to treat also of inspiration and the analysis of the act of faith. But, strictly speaking, these are not apologetic subjects. While they may logically be included in the prolegomena of dogmatic theology, they rather belong, the one to the province of Scripture-study, the other to the tract of moral theology dealing with the theological virtues.
The history of apologetic literature involves the survey of the varied attacks that have been made against the grounds of Christian, Catholic belief. It may be marked off into four great divisions. The First division is the period from the beginning of Christianity to the downfall of the Roman Empire (a. d. 476). It is chiefly characterized by the two-fold struggle of Christianity with Judaism and with paganism. The Second division is coextensive with the Middle Ages, from a. d. 476 to the Reformation. In this period we find Christianity in conflict with the Mohammedan religion and philosophy. The Third division takes in the period from the beginning of the Reformation to the rise of rationalism in England in the middle of the seventeenth century. It is the period of struggle between Catholicism and Protestantism. The Fourth division embraces the period of rationalism, from the middle of the seventeenth century down to the present day. Here we find Christianity in conflict with Deism, Pantheism, Materialism, Agnosticism, and Naturalism.
First Period. (a) Apologies in Answer to the Opposition of Judaism.—It lay in the nature of things that Christianity should meet with strong Jewish opposition. In dispensing with circumcision and other works of the Law, Christianity had incurred the imputation of running counter to God's immutable will. Again, Christ's humble and obscure life, ending in the ignominious death on the cross, was the very opposite of what the Jews expected of their Messiah. Their judgment seemed to be confirmed by the fact that Christianity attracted but an insignificant portion of the Jewish people, and spread with greatest vigour among the despised Gentiles. To justify the claims of Christianity before the Jews, the early apologists had to give an answer to these difficulties. Of these apologies the most important is the "Dialogue with Trypho the Jew" composed by Justin Martyr about 155–160. He vindicates the new religion against the objections of the learned Jew, arguing with great cogency that it is the perfection of the Old Law, and showing by an imposing array of Old Testament passages that the Hebrew prophets point to Jesus as the Messiah and incarnate Son of God. He insists also that it is in Christianity that the destiny of the Hebrew religion to become the religion of the world is to find its realization, and hence it is the followers of Christ, and not the unbelieving Jews, that are the true children of Israel. By his elaborate argument from Messianic prophecy, Justin won the grateful recognition of later apologists. Similar apologies were composed by Tertullian, "Against the Jews" (Adversus Judæos, about 200), and by St. Cyprian, "Three Books of Evidences against the Jews" (about 250). (b) Apologies in Answer to Pagan Opposition.—Of far more serious moment to the early Christian Church was the bitter opposition it met from paganism. The polytheistic religion of the Roman Empire, venerated for its antiquity, was intertwined with every fibre of the body politic. Its providential influence was a matter of firm belief. It was associated with the highest culture, and had the sanction of the greatest poets and sages of Greece and Rome. Its splendid temples and stately ritual gave it a grace and dignity that captivated the popular imagination. On the other hand, Christian monotheism was an innovation. It made no imposing display of liturgy. Its disciples were, for the most part, persons of humble birth and station. Its sacred literature had little attraction for the fastidious reader accustomed to the elegant diction of the classic authors. And so the popular mind viewed it with misgivings, or despised it as an ignorant superstition. But opposition did not end here. The uncompromising attitude of the new religion towards pagan rites was decried as the greatest impiety. The Christians were branded as atheists, and as they held aloof from the public functions also, which were invariably associated with these false rites they were accused of being enemies of the State. The Christian custom of worshipping in secret assembly seemed to add force to this charge, for secret societies were forbidden by Roman law. Nor were calumnies wanting. The popular imagination easily distorted the vaguely-known Agape and Eucharistic Sacrifice into abominable rites marked by feasting on infant flesh and by indiscriminate lust. The outcome was that the people and authorities took alarm at the rapidly spreading Church and sought to repress it by force. To vindicate the Christian cause against these attacks of paganism, many apologies were written. Some, notably the "Apology" of Justin Martyr (150), the "Plea for the Christians", by Athenagoras (177), and the "Apologetic" of Tertullian (197), were addressed to emperors for the express purpose of securing for the Christians immunity from persecution. Others were composed to convince the pagans of the folly of polytheism and of the saving truth of Christianity. Such were: Tatian, "Discourse to the Greeks" (160), Theophilus, "Three Books to Autolychus" (180), the "Epistle to Diognetus" (about 190), the "Octavius" of Minucius Felix (192), Origen, "True Discourse against Celsus" (248), Lactantius, "Institutes" (312), and St. Augustine, "City of God" (415–426). In these apologies the argument from Old Testament prophecy has a more prominent place than that from miracles. But the one on which most stress is laid is that of the transcendent excellence of Christianity. Though not clearly marked out, a twofold line of thought runs through this argument: Christianity is light, whereas paganism is darkness; Christianity is power, whereas paganism is weakness. Enlarging on these ideas, the apologists contrast the logical coherence of the religious tenets of Christianity, and its lofty ethical teaching, with the follies and inconsistencies of polytheism, the low ethical principles of its philosophers, and the indecencies of its mythology and of some of its rites. They likewise show that the Christian religion alone has the power to transform man from a slave of sin into a spiritual freeman. They compare what they once were as pagans with what they now are as Christians. They draw a telling contrast between the loose morality of pagan society and the exemplary lives of Christians, whose devotion to their religious principles is stronger than death itself.
Second Period. Christianity in conflict with Mohammedan Religion and Philosophy. The one dangerous rival with which Christianity had to contend in the Middle Ages was the Mohammedan religion. Within a century of its birth, it had torn from Christendom some of its fairest lands and ex-
