Apologetics, sometimes called fundamental theology, is that branch of Catholic theology that establishes the reasonableness of the act of faith. It is a comprehensive, systematic vindication of the grounds of Catholic belief.
In developing his arguments, the apologist employs philosophical and historical reasoning. Apologetics, however, is not a branch of philosophy or history, nor an intermediate discipline lying between philosophy and theology, but is an integral part of theology. The apologist is a theologian. Possessing the virtue of faith, he is guided by Sacred Scripture and Catholic Tradition in his choice of arguments and the way he develops them as he shows that it is reasonable to believe that God has revealed himself in Jesus Christ and that Christ established a Church to ensure that the truths he revealed would be taught without falsification until the end of time.
Apologetics in the New Testament
Christian apologetics has a long and honorable history, beginning in New Testament times, for we find Peter making a plea for apologetical reasoning when he writes, “Always be prepared to make a defense [apologia] to anyone who calls you to account for the hope that is in you” (1 Pet. 3:15).
Our Lord himself engaged in apologetical argument when he appealed to his miracles as proof that he was sent by the Father and possessed supernatural powers. His works, he said, bear witness that the Father had sent him (cf. John 5:36), and, addressing the apostle Philip, he appealed to his miracles as warrant for demanding faith in him: “Do you not believe that I am in the Father and the Father in me? . . . Believe me that I am in the Father and the Father in me; or else believe me for the sake of the works themselves” (John 14:10, 11).
It is clear from the opening verses of Luke’s Gospel that the evangelist, in writing his Gospel, had an apologetical purpose: “It seemed good to me . . . to write an orderly account for you, most excellent Theophilus, that you may know the truth concerning the things of which you have been informed” (Luke 1:3–4).
Indeed, it has been argued that all the Gospels are apologetical in scope, being written for believers to show them that their faith in Christ was well-founded and for Jews and pagans to lead them to faith in Christ.
In the Acts of the Apostles, Luke has recorded only two of the sermons that Paul addressed to pagan hearers, and both are apologetical. At Lystra, the apostle appeals to the witness that the visible creation bears to the existence of a provident Creator (cf. Acts 14:14–16), and at Athens he argues that since men, who are the children of God, possess a spiritual nature, God must be a spirit; as the Creator who gives life and breath to all that lives he must himself be a living being, not an idol of gold or silver (cf. Acts 17:23–29). Since the Jews were monotheists, there was no need to put before them arguments for the existence of the one true God. What they had to be persuaded of was that Jesus of Nazareth, who had been crucified on the orders of Pontius Pilate, was the long-awaited Messiah. Accordingly, the Christian apologetic directed to the Jews strove to show that the various Old Testament prophecies concerning the Messiah had been fulfilled in Christ. He himself laid the foundations of this line of argument when he instructed the disciples on the way to Emmaus: “Beginning with Moses and all the prophets, he interpreted to them in all the scriptures the things concerning himself” (Luke 24:27).
The crucified Messiah whom the apostles were preaching was so unlike the Messiah the Jews had been expecting that we may be sure that there was a demand for credentials establishing the truth of the apostolic message. These were provided, and they were of two kinds: (a) the witness of the apostles who had been in the Lord’s company during his public life, and (b) the witness of the Scripture that had been fulfilled in him.
We find both elements of proof in the authoritative tradition that Paul had received and that he handed on to the Corinthians (cf. 1 Cor. 15:3ff.).
Apologetics in the Early Centuries
From the time of Nero (d. A.D. 68), the Christian faith was treated by the civil authorities as an unlawful religion, and Christians were slandered by pagan propagandists as atheists who took part in cannibal feasts and indulged in sexual promiscuity. The apologists therefore faced a twofold task: to refute the charge of atheism and immorality and to appeal to the Roman Emperors, in the name of justice, for toleration for the Christian religion.
Justin Martyr wrote two apologies in Rome, the first about 150 and the second between 155 and 160. Both are primarily concerned with winning civil toleration for Christians. The First Apology is addressed to the Emperor Antoninus Pius and argues that Christians should not be condemned just for being Christians. He describes their beliefs and practices to show that in these there is nothing deserving of death. The Second Apology is addressed to the Roman Senate and pleads for justice for the Christians. Christ, he declares, is the fullness of truth, and in his teaching will be found whatever there is of truth in the teachings of such men as Socrates and Plato.
In A Dialogue with Trypho, a Jew, Justin tells how, after studying the various philosophical systems, he was led to embrace the Christian faith as the true philosophy. He then goes on to show that with the coming of Christ, the law of Moses has been abrogated and that in him the various Old Testament prophecies have been fulfilled.
Near the end of the first century, Irenaeus published his great work Against Heresies. It consists of five works, the first two being devoted to the exposition and refutation of various Gnostic heresies prevalent at the time; the last three books contain a profound theological account of the Christian faith.
The same decade saw the publication of the True Doctrine, in which Celsus, a pagan philosopher, attacked the supernatural character of Christianity. He denied that Christ worked miracles, and the arguments he brought forward to show that the testimony of the Gospels is unreliable were echoed in the writings of the Rationalists of the eighteenth and nineteenth centuries. Celsus’ book has been lost, but the text can be reconstructed from the detailed refutation that Origen published some seventy years later with the title Against Celsus.
Clement of Alexandria (d. 214), who was head of the catechetical school of Alexandria, in his book Protrepticus, an exhortation to conversion, gives evidence of a knowledge of Greek culture that is wide and deep. Having himself experienced the appeal of Greek mythology, philosophy, and the mystery cults, he is able to show how all that is of value in these is surpassingly fulfilled in Christ, the supreme Master of wisdom and Expounder of the mysteries.
All the works we have so far mentioned were written in Greek. Toward the end of the second century, works in Latin began to appear. Among these is the Octavius of Minucius Felix, a Roman lawyer who had been converted to Christianity. It is in the form of a dialogue in which one speaker, Caecilius, states the case for the pagan religion, and the other, Octavius, the case for Christianity, Minucius acting as chairman. The discussion is confined to such topics as the unity of God, divine providence, and life after death, and there is no mention of the Christian mysteries of the Trinity, the Incarnation, and the Redemption. The author was concerned only to remove the prejudices of the pagans and show how it was possible to take seriously the Christian claims.
Tertullian, a Roman lawyer who was converted to the Christian faith about the year 193, published his Apology in 197. In this work he proves with irresistible logic that the persecution of the Christians is completely opposed to the rules of Roman jurisprudence, for, although the Christians were treated as criminals, the Emperor Trajan had ordered that they were not to be sought out by the civil authorities. After refuting the customary charges of atheism, promiscuity, and infanticide, Tertullian goes on to describe in glowing terms the Christian way of life, a source of many blessings for the community at large.
Early in the fourth century, Lactantius, a rhetorician by profession, published a work in seven books, the Divine Institutes, in which he provided a systematic apology for Christianity. He points out the absurdities of the pagan myths and shows that there can be only one true God. He then argues for the divinity of Christ, appealing to his miracles and the fulfillment in him of the Old Testament prophecies, and then goes on to provide an account of the Christian moral code. His work undoubtedly served to facilitate the conversion of many educated Romans.
Eusebius of Caesarea, the first great Church historian, writing in Greek about the same time as Lactantius, published a monumental two-part apologetical work, The Preparation of the Gospel and The Proof of the Gospel. The book seems to have been written in reply to a work by Porphyry, a disciple of the neo-Platonist philosopher Plotinus, entitled Against the Christians. In the first part Eusebius refuted Porphyry’s philosophical arguments and in the second his historical arguments against the miracles and the Resurrection of Christ.
Augustine was often engaged in apologetical argument with pagans and heretics. His greatest apologetical work is The City of God, written over many years and finished in 426. The pagans were contending that the calamities that had recently befallen the Roman Empire, such as the sack of Rome by Alaric in 410, were due to the abandonment of the pagan gods. To refute this charge, Augustine shows that the pagan religion was not the source of Rome’s temporal prosperity and is still less capable of bringing man to eternal blessedness; then he goes on to break new ground by providing a Christian interpretation of the history of the human race.
Apologetics in the Middle Ages
In the Middle Ages, Christian apologists were concerned to meet the objections of Jews and Muslims and by reasoned argument convince them of the truth of the Christian faith. There were Jewish groups in the West living by the law of Moses and the Talmud. The Muslims controlled most of Spain and the coast of North Africa and posed a constant threat to the Byzantine Empire.
In the East, John Damascene published in 750 his Discussion between a Saracen and a Christian, in which he put forward a reasoned case for Christianity.
Theodore Abu Qurrah, a disciple of John, in his book God and the True Religion shows that Christianity is superior to the other religions that claim to be divinely revealed—Zoroastrianism, the Samaritan religion, Judaism, Manichaeism, Gnosticism and Islam—since it is better able to meet man’s religious needs and moreover is guaranteed by miracles.
Anselm (d. 1109) sought a more profound understanding of the truths of the Christian faith and wrote not only for the instruction of his fellow believers but also to refute the unbeliever.
The greatest apologetical work of this period is the Summa Contra Gentiles of Thomas Aquinas. He begins by pointing out that the Christian revelation contains two kinds of truth. Some can be discovered by human reason using its natural resources, whereas others are beyond the range of reason and can be known only by divine revelation. In the first three books he deals with truths of the first kind, and in the fourth he discusses the articles of faith that transcend reason, showing that, although they transcend reason, they do not contradict it. The doctrines of the heretics, on the other hand, contradict either truths known by reason or fundamental doctrines of the Christian faith.
Apologetics in Modern Times
In the sixteenth century the Catholic apologist had to meet a new challenge, for he had now to defend the Catholic faith against the attacks of the Protestant Reformers. Among the first in the field were John Fisher, with books refuting the errors of Luther and Oecolampadius, and Thomas More, who was engaged in controversy with Luther and various English heretics. They were followed by such men as Thomas Stapleton (d. 1598) and Robert Bellarmine (d. 1621). Bellarmine’s great work Disputations concerning the Controversies of the Christian Faith was an arsenal from which Catholic apologists were able to draw from the end of the sixteenth century onward. It was supplemented by the Ecclesiastical Annals of Cardinal Baronius (d. 1607), written to refute the Lutheran version of Church history put out thirty years earlier by the Centuriators of Magdeburg.
With the rise of Rationalism in the seventeenth century and its diffusion in the eighteenth, the central mysteries of the Christian faith came under attack, and orthodox Protestants as well as Catholics sprang to their defense. Blaise Pascal (d. 1662) recognized the Rationalist threat quite early and planned a systematic work of apologetics. He died before he could write the book, but the material he had collected for the project, a series of disconnected but often profound reflections, was published under the title of Pensees, in an incomplete edition in 1670.
In 1794, William Paley published A View of the Evidence of Christianity, which became a popular work of apologetics on account of its effective presentation of the facts in vigorous English prose. He followed this in 1802 with his Natural Theology, in which he developed at length the argument for the existence of God from the presence of design in nature.
In his book A Grammar of Assent, published in 1870, John Henry Cardinal Newman discussed with great subtlety the process by means of which men arrive at certainty, and in the final section of the book he provides a powerful apologetical argument for the truth of the Christian religion. Throughout his adult life, he said in 1879, he had been engaged in defending the Christian faith against the spirit of Liberalism, the doctrine that religion is not concerned with truth but is a matter of sentiment and taste.
In the early part of the twentieth century, the most eminent Catholic apologist was G. K. Chesterton (d. 1936). In 1908, there appeared a brilliant defense of the Christian faith against the errors of the day with the title Orthodoxy. In this book Chesterton took as the criterion of orthodoxy the Apostles’ Creed. In The Everlasting Man (1925), he argued for the uniqueness of man and Christianity against the naturalistic evolutionism that inspired H. G. Wells’s Outline of History.
In more recent times the Christian faith has been ably defended by C. S. Lewis (d. 1963). Refraining from debate on subjects on which orthodox Christians differed, he wrote—in defense of the central mysteries of Christianity—Miracles, The Abolition of Man, and Mere Christianity.