Reasonable Faith: Christian Truth and Apologetics
Click on image to enlarge.
by William Lane Craig
Description: Written for thoughtful readers, this updated edition by a ranking apologist presents a systematic, positive case for Christianity that reflects the latest work in astrophysics, philosophy, probability calculus, the arguments for the existence of God, and Reformed epistemology.
eBook Publisher: Crossway Books, 2009
eBookwise Release Date: July 2009
1 Reader Ratings:
Available eBook Formats: OEBFF Format (IMP) [913 KB]
Reading time: 545-763 min.
How Do I Know Christianity
Before we attempt to build a case for Christianity, we must come to grips with some very fundamental questions about the nature and relationship of faith and reason. Exactly how do we know Christianity to be true? Is it simply by a leap of faith or on the authority of the Word of God, both unrelated to reason? Does religious experience assure us of the truth of the Christian faith, so that no further justification is needed? Or is an evidential foundation for faith necessary, without which faith would be unjustified and irrational? We can better answer these questions if we briefly survey some of the most important representative thinkers of the past.
In our historical survey, let's look first at Augustine (354-430) and Thomas Aquinas (1224-1274). Their approaches were determinative for the Middle Ages.
Augustine's attitude toward faith and reason is very difficult to interpret, especially because his views apparently evolved over the years. Sometimes we get the impression that he was a strict authoritarian; that is to say, he held that the ground for faith was sheer, unquestionable, divine authority. This authority might be expressed in either the Scriptures or in the church. Thus, Augustine confessed, "I should not believe the Gospel except as moved by the authority of the Catholic Church." The authority of Scripture he held in even higher esteem than that of the church. Because the Scriptures are inspired by God, they are completely free from error and are therefore to be believed absolutely. Such a view of authority would seem to imply that reason has no role to play in the justification of belief, and sometimes Augustine gives that impression. He asserts that one must first believe before he can know. He was fond of quoting Isaiah 7:9 in the Septuagint version: "Unless you believe you shall not understand." The fundamental principle of the Augustinian tradition throughout the Middle Ages was fides quaerens intel-lectum: faith seeking understanding.
[Footnote 1: Augustine, Against the Epistle of Manichaeus Called Fundamental 5.6.]
[Footnote 2: Augustine,Letters 82.3; idem City of God 21.6.1.]
[Footnote 3: Augustine, On Free Will 2.1.6.]
But certain statements of Augustine's make it clear that he was not an unqualified authoritarian. He maintained that authority and reason cooperate in bringing a person to faith. Authority demands belief and prepares man for reason, and reason in turn leads to understanding and knowledge. But at the same time, reason is not entirely absent from authority, for one has to consider whom to believe, and the highest authority belongs to clearly known truth; that is to say, the truth, when it is clearly known, has the highest claim to authority because it demands our assent. According to Augustine, it is our duty to consider what men or what books we ought to believe in order to worship God rightly. Gerhard Strauss, in his book on Augustine's doctrine of Scripture, explains that although for Augustine Scripture is absolutely authoritative and inerrant in itself, it does not carry credibility in itself--that is, people will not automatically accept its authority upon hearing it. Therefore, there must be certain signs (indicia) of credibility that make its authority evident. On the basis of these signs, we can believe that the Scripture is the authoritative Word of God and submit to its authority. The principal signs adduced by Augustine on behalf of the authority of Scripture are miracle and prophecy. Though many religions boast of revelations showing the way of salvation, only the Scriptures have the support of miracle and prophecy, which prove it to be the true authority.
Thus, Augustine's authoritarianism would seem to be drastically qualified. Perhaps Augustine's apparent inconsistency is best explained by the medieval understanding of authority. In the early church, authority (auctoritas ) included not just theological truths but the whole tradition of past knowledge. The relationship between authority and reason was not the same as that between faith and reason.Rather it was the relationship between all past knowledge and present-day understanding. Knowledge of the past was simply accepted on the basis of authority. This seems to have been Augustine's attitude. He distinguishes between what is seen to be true and what is believed to be true. We see that something is true by either physical perception or rational demonstration. We believe that something is true on the basis of the testimony of others. Hence, with regard to miracle and prophecy, Augustine says that the trustworthiness of reports of either past or future events must be believed, not known by the intelligence. Elsewhere he declares that one should believe in God because belief in him is taught in the books of men who have left their testimony in writing that they lived with the Son of God and saw things that could not have happened if there were no God. Then he concludes that one must believe before he can know. Since for Augustine the historical evidence for miracle and prophecy lay in the past, it was in the realm of authority, not reason. Today, on the other hand, we would say that such a procedure would be an attempt to provide a rational foundation for authority via historical apologetics.
Now the obvious question at this point is, Why accept the authority of the writers of the past, whether they be the classical writers or the authors of Scripture? Clearly, if Augustine is to avoid circular reasoning, he cannot say that we should accept the authority of the evangelists because of the authority of Scripture, for it is the evangelists' testimony to miracle and prophecy that is supposed to make evident the authority of Scripture. So Augustine must either come up with some reason to accept the evangelists' testimony as reliable or abandon this historically oriented approach. Since he lacked the historical method, the first alternative was not open to him. Therefore, he chose the second. He frankly admits that the books containing the story of Christ belong to an ancient history that anyone may refuse to believe. Therefore, he turns to the present miracle of the church as the basis for accepting the authority of Scripture. He saw the very existence of the mighty and universal church as an overwhelming sign that the Scriptures are true and divine.
Now notice that Augustine is not basing the authority of Scripture on the authority of the church, for he held the Scripture's authority to exceed even that of the church. Rather, his appeal is still to the sign of miracle, not indeed the Gospel miracles, which are irretrievably removed in the past, but the present and evident miracle of the church. In The City of God he states that even if the unbeliever rejects all biblical miracles, he is still left with one stupendous miracle, which is all one needs, namely, the fact of the whole world believing in Christianity without the benefit of the Gospel miracles. It's interesting that, by appealing to a present miracle as the sign of the authority of Scripture, Augustine seems to have implicitly denied authoritarianism, since this sign was not in the past, in the realm of authority where it could only be believed, but in the present, where it could be seen and known. Be that as it may, Augustine's emphases on biblical authority and signs of credibility were to set the tone for subsequent medieval theology.
[Footnote 4: Augustine, City of God 22.5.]
T HOMAS A QUINAS
Aquinas's Summa contra gentiles, written to combat Greco-Arabic philosophy, is the greatest apologetic work of the Middle Ages and so merits our attention. Thomas develops a framework for the relationship of faith and reason that includes the Augustinian signs of credibility. He begins by making a distinction within truths about God. On the one hand, there are truths that completely surpass the capability of human reason, for example, the doctrine of the Trinity. On the other hand, many truths lie within the grasp of human reason, such as the existence of God. In the first three volumes of the Summa contra gentiles, Thomas attempts to prove these truths of reason, including the existence and nature of God, the orders of creation, the nature and end of man, and so forth. But when he comes to the fourth volume, in which he handles subjects like the Trinity, the incarnation, the sacraments, and the last things, he suddenly changes his method of approach. He states that these things are to be proved by the authority of Holy Scripture, not by natural reason. Because these doctrines surpass reason, they are properly objects of faith.
Now at first blush this seems to suggest that for Aquinas these truths of faith are mysteries, somehow "above logic." But here we must be very careful. For as I read Aquinas, that's not how he defines his terms. Rather he seems to mean that truths of faith surpass reason in the sense that they are neither empirically evident nor demonstrable with absolute certainty. He makes no suggestion that truths of faith transcend Aristotelian logic. Rather there are just no empirical facts which make these truths evident or from which these truths may be inferred. For example, although the existence of God can be proved from his effects, there are no empirical facts from which the Trinity may be inferred. Or again, the eschatological resurrection of the dead cannot be proved, because there is no empirical evidence for this future event. Elsewhere Thomas makes it clear that truths of faith cannot be demonstrated by reason alone, either. He maintains that we Christians must use only arguments that prove their conclusions with absolute certainty; for if we use mere probability arguments, the insufficiency of those arguments will only serve to confirm the non-Christian in his unbelief.
[Footnote 5: Thomas Aquinas, Summa theologiae 1a.32.1; cf. idem, Summa contra gentiles 1.9.]
Thus, the distinction Thomas makes between truths of reason and truths of faith is rather like Augustine's distinction between seeing and believing. Truths of reason may be "seen"--that is, either proved with rational certainty or accepted as empirically evident--whereas truths of faith must be believed, since they are neither empirically evident nor rationally provable. This does not mean that truths of faith are incomprehensible or "above logic."
Now because truths of faith can only be believed, does this imply that Thomas is in the end a fideist or an authoritarian? The answer seems clearly no. For like Augustine he proceeds to argue that God provides the signs of miracle and prophecy, which serve to confirm the truths of faith, though not demonstrating them directly. Because of these signs, Aquinas held that a man can see the truths of faith: "Then they are indeed seen by the one who believes; he would not believe unless he saw that they are worthy of belief on the basis of evident signs or something of this sort." Thomas calls these signs "confirmations," "arguments," and "proofs" for the truths of faith. This seems to make it clear that Aquinas believed there are good grounds for accepting the truths of faith as a whole. The proofs of miracle and prophecy are compelling, although they are indirect. Thus, for example, the doctrine of the Trinity is a truth of faith because it cannot be directly proved by any argument; nevertheless, it is indirectly proved insofar as the truths of faith taken together as a whole are shown to be credible by the divine signs.
[Footnote 6: Thomas Aquinas, Summa theologiae 2a2ae.1.4 ad 2.]
[Footnote 7: Thomas Aquinas, Summa contra gentiles 3.154; 1.6.]
Thomas's procedure, then, may be summarized in three steps: (1) Fulfilled prophecies and miracles make it credible that the Scriptures taken together as a whole are a revelation from God. (2) As a revelation from God, Scripture is absolutely authoritative. (3) Therefore, those doctrines taught by Scripture that are neither demonstrably provable nor empirically evident may be accepted by faith on the authority of Scripture. Thus, Aquinas can say that an opponent may be convinced of the truths of faith on the basis of the authority of Scripture as confirmed by God with miracles.
[Footnote 8: Ibid., 1.9.]
Again the question arises: How do we know that the purported miracles or fulfilled prophecies ever took place? The medieval thinkers, lacking the historical method, could not answer this question. They developed a philosophical framework in which the signs of credibility confirmed the truths of faith, but they had no way of proving the signs themselves. About the only argument was Augustine's indirect proof from the miracle of the church. Thus, Thomas declares,
Now such a wondrous conversion of the world to the Christian faith is a most indubitable proof that such signs did take place.... For it would be the most wondrous sign of all if without any wondrous signs the world were persuaded by simple and lowly men to believe things so arduous, to accomplish things so difficult, and to hope for things so sublime.
[Footnote 9: Ibid.]
A final word might be added. With Aquinas we see the reduction of faith to an epistemological category; that is to say, faith was no longer trust or commitment of the heart, but became a way of knowing, complementary to reason. Faith was essentially intellectual assent to doctrines not provable by reason--hence, Aquinas's view that a doctrine cannot be both known and believed: if you know it (by reason), then you cannot believe it (by faith). Thus, Aquinas diminished the view of faith as trust or commitment. This same intellectualist understanding of faith characterized the documents of the Council of Trent and of Vatican I but was adjusted in the documents of Vatican II.
The fact that the Enlightenment is also known as the Age of Reason gives us a good clue as to how thinkers of that period regarded the relationship between faith and reason. Nevertheless, there was not complete agreement on this issue, and the two figures we shall survey represent two fundamentally opposed viewpoints.
J OHN L OCKE
The thought of John Locke (1632-1704) was determinative for the eighteenth century. His Essay Concerning Human Understanding (1689) laid down the epistemological principles that were to shape religious thought during that age. Though he rejected the philosophical rationalism of Descartes, Locke was nevertheless an ardent theological rationalist. That is to say, he maintained that religious belief must have an evidential foundation and that where such a foundation is absent, religious belief is unwarranted. Locke himself attempted to provide such an evidential foundation.
Locke argued for the existence of God by means of a cosmological argument--indeed, he maintained that the existence of God is "the most obvious truth that reason discovers," having an evidence "equal to mathematical certainty."  When one moves beyond such matters of demonstrable reason into matters of faith, Locke insisted that revealed truths cannot contradict reason. God can reveal to us both truths attainable by reason (though reason gives greater certainty of these than does revelation) as well as truths unattainable by reason. The revealed truths unattainable by reason cannot contradict reason, because we shall always be more certain of the truth of reason than we shall be of a purported revelation that contradicts reason. Therefore, no proposition contrary to reason can be accepted as divine revelation. Thus, although we know that a revelation from God must be true, it still lies within the scope of reason to determine if a supposed revelation really is from God and to determine its meaning.
[Footnote 10: John Locke, An Essay Concerning Human Understanding, 4.10.1.]
[Footnote 11: Ibid., 4.18.5.]
More than that, revelation must not only be in harmony with reason but must itself be guaranteed by appropriate rational proofs that it is indeed divine. Otherwise, one degenerates into irresponsible enthusiasm:
Revelation is natural reason enlarged by a new set of discoveries communicated by God immediately, which reason vouches the truth of by the testimony and proofs it gives that they come from God. So that he that takes away reason to make way for revelation, puts out the light of both; and does much the same as if he would persuade a man to put out his eyes, the better to receive the remote light of an invisible star by a telescope. .
[Footnote 12: Ibid., 4.19.4.]
Religious enthusiasm was the form of religious expression most scorned by the intellectualist believers of the Age of Reason, and Locke would have nothing to do with it. Only if reason makes plausible that a purported revelation is genuine can that revelation be believed.
Hence, in his subsequent works The Reasonableness of Christianity (1695) and Discourse on Miracles (1690), Locke argued that fulfilled prophecy and palpable miracles furnish proof of Christ's divine mission. He set forth three criteria for discerning a genuine revelation. First, it must not be dishonoring to God or inconsistent with natural religion and the natural moral law. Second, it must not inform man of things indifferent, insignificant, or easily discovered by natural ability. Third, it must be confirmed by supernatural signs. For Locke, the chief of these signs was miracle. On the basis of Jesus' miracles, we are justified in regarding him as the Messiah and his revelation from God as true.
As the fountainhead for both Deist works and orthodox apologetics, Locke's outlook shaped the religious thought of the eighteenth century. Be they Deist or orthodox, most thinkers of the century after Locke agreed that reason was to be given priority even in matters of faith, that revelation could not contradict reason, and that reason provided the essential foundation to religious belief.
That is not to say that dissenting voices could not be heard. Henry Dodwell (1700-1784) in his Christianity Not Founded on Argument (1742) attacked the prevailing theological rationalism as antithetical to true Christianity. Dodwell was so out of step with his times that he has even been suspected of being an unbeliever who appealed to an arational, subjective basis for religious faith as a subterfuge for undermining the rationality of Christianity. It seems to me, however, that Dodwell is to be taken straightforwardly as a spokesman for the anti-rationalistic religious tradition, which was not altogether absent even during the Enlightenment.
Dodwell argues that matters of religious faith lie outside the determination of reason. God could not possibly have intended that reason should be the faculty to lead us to faith, for faith cannot hang indefinitely in suspense while reason cautiously weighs and reweighs arguments. The Scriptures teach, on the contrary, that the way to God is by means of the heart, not by means of the intellect. Faith is simply a gift of the Holy Spirit. What then is the basis of faith? Dodwell answers, authority--not indeed the arbitrary authority of the church but rather the inner light of a constant and particular revelation imparted separately and supernaturally to every individual. Dodwell's appeal is thus to the inner, faith-producing work of the Holy Spirit in each individual's heart. His subjectively based apologetic appears to have generated no following among the scholars of his day, but later a similar emphasis on the witness of the Spirit by the Wesleys and Whitefield was to be an earmark of the great revivals that opened fresh springs for the dry souls of the English laity.
During the twentieth century, theological discussion of the relationship between faith and reason has replayed many of these same themes.
KARL BARTH AND RUDOLF BULTMANN
Both the dialectical theology championed by Karl Barth (1886-1968) and the existential theology propounded by Rudolf Bultmann (1884-1976) were characterized by a religious epistemology of authoritarianism.
According to Barth, there can be no approach to God whatsoever via human reason. Apart from God's revelation in Christ, human reason comprehends absolutely nothing about God. The fundamental reason for this agnosticism concerning human knowledge of God seems to be Barth's firm commitment to the thesis that God is "wholly other" and therefore transcends all categories of human thought and logic. This belief led Barth to deny the Roman Catholic doctrine of an analogy of being between God and man. According to that doctrine, creation as the product of its Creator shares in an analogous way certain properties possessed most perfectly by God such as being, goodness, truth, and so forth. According to Barth, God is so transcendent that no analogy exists between him and the creature. Hence, it follows that there can be no natural knowledge of God at all. But God has revealed himself to man in Jesus Christ; indeed, Christ is the revelation or Word of God. In him alone there is found an analogy of faith that affords some knowledge of God. But even this knowledge seems to be experiential rather than cognitive: it is a personal encounter with the Word of God, who confronts us now and again through different forms, such as the Bible or preaching. Even in his self-disclosure God remains hidden: "He meets us as the One who is hidden, the One about whom we must admit that we do not know what we are saying when we try to say who He is." God remains incomprehensible and the propositions we assert about him are true in an incomprehensible way.
[Footnote 13: Karl Barth, The Knowledge of God and the Science of God according to the Teaching of the Reformation, trans. J. L. M. Haire and I. Henderson (New York: Scribner's, 1939), 27.]
This might lead one to think that for Barth fideism is the only route by which someone might come to the knowledge of God. This does not, however, seem to be precisely correct. For Barth emphasizes that the personal encounter with the Word of God results entirely from the sovereign, divine initiative. Lost in sin, man cannot even begin to move in the direction of faith, so that even a leap of faith is impossible for him. No, it must be God who breaks into man's indolent sinfulness to confront him with the Word of God. As Barth writes, "Knowledge of God is a knowledge completely effected and determined from the side of its object, from the side of God." Or again, "the fact that he did come to this decision, that he really believed, and that he actually had freedom to enter this new life of obedience and hope--all this was not the work of his spirit, but the work of the Holy Spirit." Barth believed that the Reformation doctrine of justification by grace through faith is incompatible with any human initiative--even fideism. If knowing God depends wholly on God's grace, then even the act of faith would be a sinful work were it not wholly wrought by God. If it be asked how one knows that it is indeed the Word of God that confronts him and not a delusion, Barth would simply respond that such a question is meaningless. When the Word of God confronts a man, he is not free to analyze, weigh, and consider as a disinterested judge or observer--he can only obey. The authority of the Word of God is the foundation for religious belief.
[Footnote 14: Karl Barth, Dogmatics in Outline, trans. G. J. Thomson (New York: Philosophical Library, 1947), 24.]
[Footnote 15: Barth, Knowledge, 109.]
Like Barth, Bultmann also rejects any human apprehension of the Word of God (which he seems to identify primarily with the call to authentic existence embodied in the gospel) apart from faith. Bultmann construes faith in epistemological categories, opposing it to knowledge based on proof. In the existentialist tradition, he considers it essential to faith that it involves risk and uncertainty. Therefore, rational evidence is not only irrelevant, but actually contrary to faith. Faith, in order to be faith, must exist in an evidential vacuum. For this reason Bultmann denies any significance for the Christian message to the historical Jesus, apart from his bare existence. Bultmann recognizes that Paul in 1 Corinthians 15 does "think that he can guarantee the resurrection of Christ as an objective fact by listing the witnesses who had seen him risen." But he characterizes such historical argumentation as "fatal" because it tries to produce proof for the Christian proclamation.  Should an attempt at proof succeed, this would mean the destruction of faith. Only a decision to believe wholly apart from evidence will bring one into contact with the existential significance of the gospel. Bultmann emphasizes that this does not mean that such a step is made arbitrarily or lightheartedly. No, the existential issues of life and death weigh so heavily that this decision to believe is the most important and awesome step a person can take. But it must be taken in the absence of any rational criteria for choice.
[Footnote 16: Rudolf Bultmann, Theologie des Neuen Testaments, 7th ed., ed. O. Merk (Tübingen: J.C.B. Mohr, 1961), 295.]
[Footnote 17: Rudolf Bultmann, "Reply to the Theses of J. Schniewind," in Kerygma and Myth, ed. H.-W. Bartsch, trans. R. H. Fuller (London: SPCK, 1953), 1:112.]
This might lead one to think that Bultmann is a pure fideist; but again this does not seem quite correct. For he insists that the very authority of the Word of God strips away all demands for criteria: "As though God had to justify himself to man! As though every demand for justification (including the one concealed in the demand for criteria) did not have to be dropped as soon as the face of God appears!" As Wolfhart Pannenberg explains, the "basic presupposition underlying German Protestant theology as expressed by Barth or Bultmann is that the basis of theology is the self-authenticating Word of God which demands obedience." Thus, it would seem that in both dialectical and existential theology the final appeal is authoritarian.
[Footnote 18: Rudolf Bultmann, "The Case for Demythologizing: A Reply," in Kerygma and Myth, ed. H.-W. Bartsch, trans. R. H. Fuller (London: SPCK, 1953), 2:191.]
[Footnote 19: Wolfhart Pannenberg, ed. Revelation as History, trans. D. Granskou (London: Macmillan, 1968), 9.]
Pannenberg's rigorously evidential approach to theological questions was widely acclaimed as ushering in a new phase in European Protestant theology. In 1961 a circle of young theologians for whom Pannenberg served as the principal spokesman asserted in their manifesto Offenbarung als Geschichte [Revelation as History] that revelation ought to be understood exclusively in terms of God's acts in history, not as some self-authenticating Word.
Because this "Word," which was understood as God's self-disclosure in a divine-human encounter, needs no external authentication, theology, according to Pannenberg, has depreciated the relevance of history to faith and walled itself off against secular knowledge. On the one hand, Bultmann's existentialist theology neglected objective historical facticity in favor of finding the conditions for authentic human existence in the apostolic proclamation, to which historical facts are thought to be strictly irrelevant. On the other hand, Barth's understanding of peculiarly Christian events as belonging, not to the course of ordinary, investigable history, but rather to redemptive history, which is closed to historical research, equally devalues real history. Both schools share a common motive in their depreciation of the importance of history for faith, namely, the desire to secure for faith an impregnable stronghold against the assaults of modern historical-critical studies. Dialectical theology fled into the harbor of supra-history, supposedly safe from the historical-critical floodtide, while existential theology withdrew from the course of objective history to the subjective experience of human authenticity. Theology's attempt at self-isolationism backfired, however, because the secular sciences turned upon it to criticize and contradict it. "For much too long a time faith has been misunderstood to be subjectivity's fortress into which Christianity could retreat from the attacks of scientific knowledge. Such a retreat into pious subjectivity can only lead to destroying any consciousness of the truth of the Christian faith."
[Footnote 20: Wolfhart Pannenberg, "The Revelation of God in Jesus of Nazareth," in New Frontiers in Theology, vol. 3: Theology as History, ed. J. M. Robinson and J. B. Cobb Jr. (New York: Harper & Row, 1967), 131.]
Therefore, if Christianity is to make any meaningful claim to truth, it must, according to Pannenberg, submit to the same procedures of testing and verification that are employed in the secular sciences. This method of verification will be indirect, for example, by means of historical research. A theological interpretation of history will be tested positively by "its ability to take into account all known historical details," and negatively by "the proof that without its specific assertions the accessible information would not be at all or would be only incompletely explicable." Since the Christian faith is based on a real past event, and since there is no way to know the past other than by historical-critical research, it follows that the object of Christian faith cannot remain untouched by the results of such research. On the one hand, a kerygmatic Christ utterly unrelated to the real, historical Jesus would be "pure myth"; and on the other hand, a Christ known only through dialectical encounter would be impossible to distinguish from "self-delusion." Therefore, the unavoidable conclusion is that the burden of proving that God has revealed himself in Jesus of Nazareth must fall upon the historian.
[Footnote 21: Wolfhart Pannenberg, "Redemptive Event and History," in Basic Questions in Theology, trans. G. Kehm (Philadelphia: Fortress, 1970), 1:78.]
[Footnote 22: Wolfhart Pannenberg, Jesus--God and Man, trans. L. L. Wilkins and D. A. Priebe (London: SCM, 1968), 27-28.]
Pannenberg acknowledges that if the historical foundation for faith were removed, then Christianity should be abandoned. He is, however, confident that given the historical facts that we now have, this eventuality will not occur. Pan-nenberg realizes that the results of historical investigation always retain a degree of uncertainty, but nevertheless, through this "precarious and provisional" way a knowledge of the truth of Christianity is possible. Without this factual foundation logically prior to faith, faith would be reduced to gullibility, credulity, or superstition. Only this evidential approach, in contrast to the subjectivism of modern theology, can establish Christianity's truth claim. The historical facts at the foundation of Christianity are reliable, and therefore we can base our faith, our lives, and our future on them.
Appealing to what he (erroneously, I think) calls the Reformed objection to natural theology, Alvin Plantinga has launched a sustained attack on theological rationalism. Plantinga maintains that belief in God and in the central doctrines of Christianity is both rational and warranted wholly apart from any evidential foundations for belief.
This brings him into conflict with what he calls the evidentialist objection to theistic belief. According to the evidentialist, one is rationally justified in believing a proposition to be true only if that proposition is either foundational to knowledge or is established by evidence that is ultimately based on such a foundation. According to this viewpoint, since the proposition "God exists" is not foundational, it would be irrational to believe this proposition apart from rational evidence for its truth.
But, Plantinga asks, why can't the proposition "God exists" be itself part of the foundation, so that no rational evidence is necessary? The evidentialist replies that only propositions that are properly basic can be part of the foundation of knowledge. What, then, are the criteria that determine whether or not a proposition is properly basic? Typically, the evidentialist asserts that only propositions that are self-evident or incorrigible are properly basic. For example, the proposition "The sum of the squares of the two sides of a right triangle is equal to the square of the hypotenuse" is self-evidently true. Similarly, the proposition "I feel pain" is incorrigibly true, since even if I am only imagining my injury, it is still true that I feel pain. Since the proposition "God exists" is neither self-evident nor incorrigible, it is not properly basic and therefore requires evidence if it is to be believed. To believe this proposition without evidence is therefore irrational.
Plantinga does not deny that self-evident and incorrigible propositions are properly basic, but he does ask how we know that these are the only properly basic propositions or beliefs. If they are, then we are all irrational, since we commonly accept numerous beliefs that are not based on evidence and that are neither self-evident nor incorrigible. For example, take the belief that the world was not created five minutes ago with built-in memory traces, food in our stomachs from the breakfasts we never really ate, and other appearances of age. Surely it is rational to believe that the world has existed longer than five minutes, even though there is no evidence for this. The evidentialist's criteria for proper basicality must be flawed.In fact, what about the status of those criteria? Is the proposition "Only propositions that are self-evident or incorrigible are properly basic" itself properly basic?Apparently not, for it is certainly not self-evident or incorrigible. Therefore, if we are to believe this proposition, we must have evidence that it is true. But there is no such evidence. The proposition appears to be just an arbitrary definition--and not a very plausible one at that! Hence, the evidentialist cannot exclude the possibility that belief in God is a properly basic belief.
And in fact, Plantinga maintains, following John Calvin, belief in God is properly basic. Man has an innate, natural capacity to apprehend God's existence even as he has a natural capacity to accept truths of perception (like "I see a tree"). Given the appropriate circumstances--such as moments of guilt, gratitude, or a sense of God's handiwork in nature--man naturally apprehends God's existence. In the same way that certain perceptual beliefs, like "I see a tree," are properly basic given the appropriate circumstances, so belief in God is properly basic in appropriate circumstances. Neither the tree's existence nor God's existence is inferred from one's experience of the circumstances. But being in the appropriate circumstances is what renders one's belief properly basic; the belief would be irrational were it to be held under inappropriate circumstances. Thus, the basic belief that God exists is not arbitrary, since it is properly held only by a person placed in appropriate circumstances. Similarly, taking belief in God as properly basic does not commit one to the relativistic view that virtually any belief can be properly basic for a normal adult. In the absence of appropriate circumstances, various beliefs taken as basic by certain persons will be arbitrarily and irrationally held. Even in the absence of an adequate criterion of proper basicality to replace the flawed evidentialist criterion, the fact is that we can know that some beliefs are just not properly basic. Thus, the Christian who takes belief in God as properly basic can legitimately reject the proper basicality of other beliefs. Plantinga thus insists that his epistemology is not fideistic; the deliverances of reason include not only inferred propositions, but also properly basic propositions. God has so constructed us that we naturally form the belief in his existence under appropriate circumstances, just as we do the belief in perceptual objects, the reality of the past, and so forth. Hence, belief in God is among the deliverances of reason, not faith.
Plantinga emphasizes that the proper basicality of the belief that God exists does not imply its indubitability. This belief is defeasible; that is to say, it can be defeated by other incompatible beliefs which come to be accepted by the theist. In such a case, the individual in question must give up some of his beliefs if he is to remain rational, and perhaps it will be his belief in God that is jettisoned. Thus, for example, a Christian who encounters the problem of evil is faced with a potential defeater of his belief in God. If he is to remain rational in his Christian belief, he must have an answer for the defeater. This is where Christian apologetics comes in; it can help to formulate answers to potential defeaters, such as the Free Will Defense in response to the problem of evil. But Plantinga also argues that in some cases, the original belief itself may so exceed its alleged defeater in rational warrant that it becomes an intrinsic defeater of its ostensible defeater. He gives the example of someone accused of a crime and against whom all the evidence stands, even though that person knows he is innocent. In such a case, that person is not rationally obligated to abandon belief in his own innocence and to accept instead the evidence that he is guilty. The belief that he did not commit the crime intrinsically defeats the defeaters brought against it by the evidence. Plantinga makes the theological application by suggesting that belief in God may similarly intrinsically defeat all the defeaters that might be brought against it. Plantinga suggests that the mechanisms which could produce so powerful a warrant for belief in God are the implanted, natural sense of the divine (Calvin's sensus divinitatis), strengthened and accentuated by the testimony of the Holy Spirit.
[Footnote 23: See his extended discussion in Alvin Plantinga, Warranted Christian Belief (New York: Oxford University Press, 2000).]
Plantinga argues that belief in God is not merely rational for the person who takes it as properly basic, but that this belief is so warranted that such a person can be said to know that God exists. A belief that is merely rational could in fact be false. When we say that a belief is rational, we mean that the person holding it is within his epistemological rights in so doing or that he exhibits no defect in his noetic structure in so believing. But in order that some belief constitutes knowledge, it must be true and in some sense justified or warranted for the person holding it.
The notion of warrant, that quality which differentiates knowledge from merely true belief, is philosophically controversial, and it is to the analysis of this notion that Plantinga then turns. He first exposits and then criticizes all major theories of warrant which are offered by epistemologists today, such as deontologism, reliablism, coherentism, and so forth. Fundamentally, Plantinga's method of exposing the inadequacy of such theories is to construct thought experiments or scenarios in which all the conditions for warrant stipulated by a theory are met and yet in which it is obvious that the person in question does not have knowledge of the proposition which he believes because his cognitive faculties are malfunctioning in forming the belief. This common failing suggests that rational warrant inherently involves the notion of the proper functioning of one's cognitive faculties. But this raises the troublesome question, what does it mean for one's cognitive faculties to be "functioning properly"? Here Plantinga drops a bomb into mainstream epistemology by proposing a peculiarly theistic account of rational warrant and proper functioning, namely, that one's cognitive faculties are functioning properly only if they are functioning as God designed them to.
Although he adds various subtle philosophical qualifications, the basic idea of Plantinga's account is that a belief is warranted for a person just in the case his cognitive faculties are, in forming that belief, functioning in an appropriate environment as God designed them to. The more firmly such a person holds the belief in question, the more warrant it has for him, and if he believes it firmly enough, it has sufficient warrant to constitute knowledge. With respect to the belief that God exists, Plantinga holds that God has so constituted us that we naturally form this belief under certain circumstances; since the belief is thus formed by properly functioning cognitive faculties in an appropriate environment, it is warranted for us, and, insofar as our faculties are not disrupted by the noetic effects of sin, we shall believe this proposition deeply and firmly, so that we can be said, in virtue of the great warrant accruing to this belief for us, to know that God exists.
But what about specifically Christian beliefs? How can one be justified and warranted in holding to Christian theism? In order to answer this question, Plan-tinga extends his account to include not just the sensus divinitatis but also the inner witness or instigation of the Holy Spirit.
The extended account postulates that our fall into sin has had disastrous cognitive and affective consequences. The sensus divinitatis has been damaged and deformed, its deliverances muted. Moreover, our affections have been skewed, so that we resist what deliverances of the sensus divinitatis remain, being self-centered rather than God-centered. God in his grace needed to find a way to inform us of the plan of salvation which he has made available, and he has chosen to do so by the trifold means of the Scriptures, which lay out the great truths of the gospel, the work of the Holy Spirit, who repairs the cognitive and affective damage of sin so that we can believe the great truths of the gospel, and, finally, faith, which is the principal work of the Holy Spirit produced in believers' hearts. In Plantinga's view the internal instigation of the Holy Spirit is the close analogue of a cognitive faculty in that it, too, is a belief-forming "mechanism." As such the beliefs formed by this process meet the conditions for warrant. Therefore, one can be said to know the great truths of the gospel through the instigation of the Holy Spirit.
Because we know the great truths of the gospel through the Holy Spirit's work, we have no need of evidence for them. Rather they are properly basic for us, both with respect to justification and warrant. Plantinga therefore affirms that "according to the model, the central truths of the Gospel are self-authenticating"; that is to say, "They do not get their evidence or warrant by way of being believed on the evidential basis of other propositions."
[Footnote 24: Ibid., 261-62.]
"How do I know that Christianity is true?" Probably every Christian has asked himself that question. "I believe that God exists, I believe that Jesus rose from the dead, and I've experienced his life-changing power in my life, but how do I know it's really true?" The problem becomes especially acute when we're faced with someone who either does not believe in God or Jesus or who adheres to some other world religion. They may demand of us how we know that Christianity is true and to prove it to them. What are we supposed to say? How do I know that Christianity is true?
In answering this question, I have found it helpful to distinguish between knowing Christianity to be true and showing Christianity to be true.
Knowing Christianity to Be True
Here I want to examine two points: first, the role of the Holy Spirit, and second, the role of argument and evidence.
ROLE OF THE HOLY SPIRIT
I think that Dodwell and Plantinga are correct that, fundamentally, the way we know Christianity to be true is by the self-authenticating witness of God's Holy Spirit. Now what do I mean by that? I mean that the experience of the Holy Spirit is veridical and unmistakable (though not necessarily irresistible or indubitable) for him who has it; that such a person does not need supplementary arguments or evidence in order to know and to know with confidence that he is in fact experiencing the Spirit of God; that such experience does not function in this case as a premise in any argument from religious experience to God, but rather is the immediate experiencing of God himself; that in certain contexts the experience of the Holy Spirit will imply the apprehension of certain truths of the Christian religion, such as "God exists," "I am condemned by God," "I am reconciled to God," "Christ lives in me," and so forth; that such an experience provides one not only with a subjective assurance of Christianity's truth, but with objective knowledge of that truth; and that arguments and evidence incompatible with that truth are overwhelmed by the experience of the Holy Spirit for him who attends fully to it.
It seems to me that the New Testament teaches such a view with respect to both the believer and the unbeliever alike. Now at first blush it might seem self-defeating or perhaps circular for me to appeal to scriptural proof texts concerning the witness of the Spirit, as if to say that we believe in the Spirit's witness because the Scripture says there is such a witness. But insofar as ours is an "in-house" discussion among Christians, it is entirely appropriate to lay out what Scripture teaches on religious epistemology. In interacting with a non-Christian, by contrast, one would simply say that we Christians do in fact experience the inner testimony of God's Spirit.
First, let's look at the role of the Holy Spirit in the life of the believer. When a person becomes a Christian, he automatically becomes an adopted son of God and is indwelt with the Holy Spirit: "for in Christ Jesus you are all sons of God, through faith.... And because you are sons, God has sent the Spirit of his Son into our hearts, crying, 'Abba! Father!'" (Gal. 3:26; 4:6 esv). Paul emphasizes the point in Romans 8. Here he explains that it is the witness of the Holy Spirit with our spirit that allows us to know that we are God's children: "For you did not receive the spirit of slavery to fall back into fear, but you have received the spirit of sonship. When we cry, 'Abba! Father!' it is the Spirit himself bearing witness with our spirit that we are children of God" (Rom. 8:15-16 rsv). Paul uses the term plerophoria (complete confidence, full assurance) to indicate that the believer has knowledge of the truth as a result of the Spirit's work (Col. 2:2; 1 Thess. 1:5; cf. Rom. 4:21; 14:5; Col. 4:12). Sometimes this is called "assurance of salvation" by Christians today; and assurance of salvation entails certain truths of Christianity, such as "God forgives my sin," "Christ has reconciled me to God," and so on, so that in having assurance of salvation one has assurance of these truths.
The apostle John also makes quite clear that it is the Holy Spirit within us who gives believers conviction of the truth of Christianity. "But you have been anointed by the Holy One, and you all know ... the anointing which you received from him abides in you, and you have no need that any one should teach you; as his anointing teaches you about everything, and is true, and is no lie, just as it has taught you, abide in him" (1 John 2:20, 27 rsv). Here John explains that it is the Holy Spirit who teaches the believer the truth of divine things. John is clearly echoing the teaching of Jesus himself, when he says, "But the Counselor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your remembrance all that I have said to you" (John 14:26 rsv). Now the truth that the Holy Spirit teaches us is not, I'm convinced, the subtleties of Christian doctrine.There are too many Spirit-filled Christians who differ doctrinally for that to be the case. What John is talking about is the inner assurance the Holy Spirit gives of the basic truths of the Christian faith, what Plantinga calls the great truths of the gospel. This assurance does not come from human arguments but directly from the Holy Spirit himself.
Now someone might point to 1 John 4:1-3 (esv) as evidence that the testimony of the Holy Spirit is not self-authenticating, but needs to be tested:
Beloved, do not believe every spirit, but test the spirits to see whether they are of God; for many false prophets have gone out into the world. By this you know the Spirit of God: every spirit which confesses that Jesus Christ has come in the flesh is of God, and every spirit which does not confess Jesus is not of God. This is the spirit of antichrist.
But such an understanding would be a misinterpretation of the passage. John is not talking about testing the witness of the Spirit in our own hearts; rather he's talking about testing people who come to you claiming to be speaking by the Holy Spirit. He referred to the same people earlier: "Children, it is the last hour; and as you have heard that antichrist is coming, so now many antichrists have come; therefore we know that it is the last hour. They went out from us, but they were not of us" (1 John 2:18-19 esv). John never encourages the believer to doubt the witness of the Spirit in his own heart; rather he says that if someone else comes claiming to speak by the Holy Spirit, then, since the situation is external to oneself and involves additional truth claims not immediately apprehended, we must test that person in order to determine if his claim is true. But in our own lives, the inner witness of God's Spirit is sufficient to assure us of the truths to which he testifies.
John also underlines other teachings of Jesus on the work of the Holy Spirit. For example, according to Jesus it is the indwelling Holy Spirit that gives the believer certainty of knowing that Jesus lives in him and that he is in Jesus, in the sense of being united with him:
And I will pray the Father, and he will give you another Counselor, to be with you for ever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him; you know him, for he dwells with you, and will be in you.... In that day you will know that I am in my Father, and you in me, and I in you.
(John 14:16-17, 20 rsv)
John teaches the same thing: "And by this we know that he abides in us, by the Spirit which he has given us.... By this we know that we abide in him and he in us, because he has given us of his own Spirit" (l John 3:24; 4:13 rsv). John uses his characteristic phrase "by this we know" to emphasize that as Christians we have a confident knowledge that our faith is true, that we really do abide in God, and God really does live in us. In fact John goes so far as to contrast the confidence which the Spirit's testimony brings to that brought by human evidence:
This is he who came by water and blood, Jesus Christ, not with the water only but with the water and the blood. And the Spirit is the witness, because the Spirit is the truth. There are three witnesses, the Spirit, the water, and the blood; and these three agree. If we receive the testimony of men, the testimony of God is greater; for this is the testimony of God that he has borne witness to his Son. He who believes in the Son of God has the testimony in himself. He who does not believe God has made him a liar, because he has not believed in the testimony that God has borne to his Son. (1 John 5:6-10 rsv)
The "water" here probably refers to Jesus' baptism, and the "blood" to his crucifixion, those being the two events which marked the beginning and end of his earthly ministry. "The testimony of men" is therefore nothing less than the apostolic testimony to the events of Jesus' life and ministry. Though John had laid such great weight on precisely that apostolic testimony in his Gospel (John 20:31; 21:24), here he declares that even though we quite rightly receive this testimony, still the inner testimony of the Holy Spirit is even greater! As Christians we have the testimony of God living within us, the Holy Spirit who bears witness with our spirit that we are children of God.
Thus, although arguments and evidence may be used to support the believer's faith, they are never properly the basis of that faith. For the believer, God is not the conclusion of a syllogism; he is the living God of Abraham, Isaac, and Jacob dwelling within us. How then does the believer know that Christianity is true?He knows because of the self-authenticating witness of God's Spirit who lives within him.
But what about the role of the Holy Spirit in the life of an unbeliever? Since the Holy Spirit does not indwell him, does this mean that he must rely only upon arguments and evidence to convince him that Christianity is true? No, not at all. According to the Scripture, God has a different ministry of the Holy Spirit especially geared to the needs of the unbeliever. Jesus describes this ministry in John 16:7-11 (rsv):
It is to your advantage that I go away, for if I do not go away, the Counselor will not come to you; but if I go, I will send him to you. And when he comes, he will convince the world concerning sin and righteousness and judgment: concerning sin, because they do not believe in me; concerning righteousness, because I go to the Father, and you will see me no more; concerning judgment, because the ruler of this world is judged.
Here the Holy Spirit's ministry is threefold: he convicts the unbeliever of his own sin, of God's righteousness, and of his condemnation before God. The unbeliever so convicted can therefore be said to know such truths as "God exists," "I am guilty before God," and so forth.
This is the way it has to be. For if it weren't for the work of the Holy Spirit, no one would ever become a Christian. According to Paul, natural man left to himself does not even seek God: "None is righteous, no, not one; no one understands, no one seeks for God" (Rom 3:10-11 esv). Unregenerate man cannot understand spiritual things: "The unspiritual man does not receive the gifts of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned" (1 Cor. 2:14 rsv). And he is hostile to God: "For the mind that is set on the flesh is hostile to God; for it does not submit to God's law; indeed, it cannot" (Rom. 8:7 esv). As Jesus said, men love darkness rather than light. Left to himself, natural man would never come to God.
The fact that we do find people who are seeking God and are ready to believe in Christ is evidence that the Holy Spirit has already been at work, convicting them and drawing them to him. As Jesus said, "No one can come to me unless the Father who sent me draws him" (John 6:44 esv).
Therefore, when a person refuses to come to Christ, it is never just because of lack of evidence or because of intellectual difficulties: at root, he refuses to come because he willingly ignores and rejects the drawing of God's Spirit on his heart. No one in the final analysis really fails to become a Christian because of lack of arguments; he fails to become a Christian because he loves darkness rather than light and wants nothing to do with God. But anyone who responds to the drawing of God's Spirit with an open mind and an open heart can know with assurance that Christianity is true, because God's Spirit will convict him that it is. Jesus said, "My teaching is not mine, but his who sent me; if any man's will is to do his will, he shall know whether the teaching is from God or whether I am speaking on my own authority" (John 7:16-17 rsv). Jesus affirms that if anyone is truly seeking God, then he will know that Jesus' teaching is truly from God.
So then for the unbeliever as well as for the believer, it is the testimony of God's Spirit that ultimately assures him of the truth of Christianity. The unbeliever who is truly seeking God will be convinced of the truth of the Christian message.
Therefore, we find that for believer and unbeliever alike it is the self-authenticating work of the Holy Spirit that supplies knowledge of Christianity's truth. Thus, I would agree that belief in the God of the Bible is a properly basic belief and emphasize that it is the ministry of the Holy Spirit that supplies the circumstances for its proper basicality. And because this belief is formed in response to the self-disclosure of God himself, who needs no external authentication, it is not merely rational for us, but constitutes knowledge. We can know Christianity's truth.
R OLE OF A RGUMENT AND E VIDENCE
But what about the second point: the role of argument and evidence in knowing Christianity to be true? I've already said that it is the self-authenticating witness of the Holy Spirit that gives us the fundamental knowledge of Christianity's truth. Therefore, the only role left for argument and evidence to play is a subsidiary role. I think Martin Luther correctly distinguished between what he called the magisterial and ministerial uses of reason. The magisterial use of reason occurs when reason stands over and above the gospel like a magistrate and judges it on the basis of argument and evidence. The ministerial use of reason occurs when reason submits to and serves the gospel. In light of the Spirit's witness, only the ministerial use of reason is legitimate. Philosophy is rightly the handmaid of theology. Reason is a tool to help us better understand and defend our faith; as Anselm put it, ours is a faith that seeks understanding. A person who knows that Christianity is true on the basis of the witness of the Spirit may also have a sound apologetic which reinforces or confirms for him the Spirit's witness, but it does not serve as the basis of his belief. If the arguments of natural theology and Christian evidences are successful, then Christian belief is warranted by such arguments and evidences for the person who grasps them, even if that person would still be warranted in their absence. Such a person is doubly warranted in his Christian belief, in the sense that he enjoys two sources of warrant.
One can envision great benefits of having such a dual warrant of one's Christian beliefs. Having sound arguments for the existence of a Creator and Designer of the universe or evidence for the historical credibility of the New Testament records of the life of Jesus in addition to the inner witness of the Spirit could increase one's confidence in the veracity of Christian truth claims. On Plantinga's epistemological model, at least, one would then have greater warrant for believing such claims. Greater warrant could in turn lead an unbeliever to come to faith more readily or inspire a believer to share his faith more boldly. Moreover, the availability of independent warrant for Christian truth claims apart from the Spirit's witness could help predispose an unbeliever to respond to the drawing of the Holy Spirit when he hears the gospel and could provide the believer with support in times of spiritual dryness or doubt when the Spirit's witness seems eclipsed. One could doubtless think of many other ways in which the possession of such dual warrant for Christian beliefs would be beneficial. Should a conflict arise between the witness of the Holy Spirit to the fundamental truth of the Christian faith and beliefs based on argument and evidence, then it is the former which must take precedence over the latter, not vice versa.
There is a danger in all this so far. Some persons might say that we should never seek to defend the faith. Just preach the gospel and let the Holy Spirit work! But this attitude is unbalanced and unscriptural, as we'll see in a moment. For now, let's just note in passing that as long as reason is a minister of the Christian faith, Christians should employ it.
Some people disagree with what I've said about the role of argument and evidence. They would say that reason can be used in a magisterial role, at least by the unbeliever. They ask how else we could determine which is true, the Bible, the Qur'an, or the Book of Mormon, unless we use argument and evidence to judge them. The Muslim or the Mormon also claims to have a witness of God's Spirit or a "burning in the bosom" which authenticates to him the truth of his scriptures. Christian claims to a subjective experience seem to be on a par with similar non-Christian claims.
But how is the fact that other persons claim to experience a self-authenticating witness of God's Spirit relevant to my knowing the truth of Christianity via the Spirit's witness? The existence of an authentic and unique witness of the Spirit does not exclude the existence of false claims to such a witness. How, then, does the existence of false claims of the Spirit's witness to the truth of a non-Christian religion do anything logically to undermine the fact that the Christian believer does possess the genuine witness of the Spirit? Why should I be robbed of my joy and assurance of salvation simply because someone else falsely pretends, sincerely or insincerely, to the Spirit's witness? If a Mormon or Muslim falsely claims to experience the witness of God's Spirit in his heart, that does nothing to undermine the veridicality of my experience.
But someone may insist, "But how do you know that your experience isn't also spurious?" That question has already been answered: the experience of the Spirit's witness is self-authenticating for him who really has it. The Spirit-filled Christian can know immediately that his claim to the Spirit's witness is true despite the false claims made by persons adhering to other religions.
Perhaps the most plausible spin to put on this objection is to say that false claims to a witness of the Holy Spirit ought to undermine my confidence in the reliability of the cognitive faculties which form religious beliefs, since those faculties apparently so often mislead people. The fact that so many people apparently sincerely, yet falsely, believe that God's Spirit is testifying to them of the truth of their religious beliefs ought therefore to make us very leery concerning our own experience of God.
There are at least two things wrong with this construal of the objection. First, the Christian needn't say that non-Christian religious experience is simply spurious. It may well be the case that adherents of other religions do enjoy a veridical experience of God as the Ground of Being on whom we creatures are dependent or as the Moral Absolute from whom values derive or even as the loving Father of mankind. So we're not at all committed to claiming that the cognitive faculties responsible for people's religious beliefs are fundamentally unreliable. Second, the objection unjustifiably assumes that the witness of the Holy Spirit is the product of human cognitive faculties or is indistinguishable from their outputs. In fact, non-Christian religious experience, such as Buddhist or Hindu religious experience, is typically very different from Christian experience. Why should I think that when a Mormon claims to experience a "burning in the bosom" he is having an experience qualitatively indistinguishable from the witness of the Holy Spirit that I enjoy? I see no reason to think that non-veridical religious experiences are indistinguishable from the witness of the Holy Spirit. One way to get some empirical evidence for this would be simply to ask ex-Mormons and Muslims who have become Christians if their experience of God in Christianity is identical to what they had before their conversion.
Someone might say, "But can't neuroscientists artificially induce in the brain religious experiences which are non-veridical and yet seem to be like the witness of the Holy Spirit?" In fact, this is not true. The sort of religious experiences which have been artificially induced by brain stimulus have been more akin to pantheistic religious experiences, a sense of oneness with the All, rather than Christian experience of God's personal presence and love. But more importantly, the fact that a non-veridical experience can be induced which is qualitatively identical to a veridical experience does absolutely nothing to undermine the fact that there are veridical experiences and that we are rational in taking our experiences to be veridical. Otherwise, one would have to say that because neuroscientists can artificially cause us to see and hear things that aren't really there, our senses of sight and hearing are unreliable or untrustworthy! Just because a neurologist could stimulate my brain to make me think that I'm having an experience of God is no proof at all that on some occasion when he is not stimulating my brain that I do not have a genuine experience of God. So the objection to a self-authenticating witness of the Spirit on the basis of false claims to such an experience does not undermine my rationally trusting in the deliverances of the Holy Spirit's witness.
Moreover, let me suggest two theological reasons why I think those Christians who support the magisterial role of reason are mistaken. First, such a role would consign most Christians to irrationality. The vast majority of the human race have neither the time, training, nor resources to develop a full-blown Christian apologetic as the basis of their faith. Even the proponents of the magisterial use of reason at one time in the course of their education presumably lacked such an apologetic. According to the magisterial role of reason, these persons should not have believed in Christ until they finished their apologetic. Otherwise, they would be believing for insufficient reasons. I once asked a fellow seminary student, "How do you know Christianity is true?" He replied, "I really don't know." Does that mean he should give up Christianity until he finds rational arguments to ground his faith? Of course not! He knew Christianity is true because he knew Jesus, regardless of rational arguments. The fact is that we can know the truth whether we have rational arguments or not.
Second, if the magisterial role of reason were legitimate, then a person who had been given poor arguments for Christianity would have a just excuse before God for not believing in him. Suppose someone had been told to believe in God on the basis of an invalid argument. Could he stand before God on the judgment day and say, "God, those Christians only gave me a lousy argument for believing in you. That's why I didn't believe"? Of course not! The Bible says all men are without excuse. Even those who are given no good reason to believe and many persuasive reasons to disbelieve have no excuse, because the ultimate reason they do not believe is that they have deliberately rejected God's Holy Spirit.Therefore, the role of rational argumentation in knowing Christianity to be true is the role of a servant. A person knows Christianity is true because the Holy Spirit tells him it is true, and while argument and evidence can be used to support this conclusion, they cannot legitimately overrule it.
Showing Christianity to Be True
Such are the roles of the Holy Spirit and of argument in knowing Christianity to be true. But what about their roles in showing Christianity to be true? Here things are somewhat reversed.
ROLE OF REASON
Let's look first at the role of argument and evidence in showing that Christianity is true. Here we're concerned about how to prove to another person that our faith is true. Even if I myself know personally on the basis of the Spirit's witness that Christianity is true, how can I demonstrate to somebody else that what I believe is true?
Consider again the case of the Christian confronted with an adherent of some other world religion who also claims to have a self-authenticating experience of God. William Alston points out that this situation taken in isolation results in an epistemic standoff. For neither person knows how to convince the other that he alone has a veridical, rather than delusory, experience. This standoff does not undermine the rationality of the Christian's belief, for even if his process of forming his belief is as reliable as can be, there's no way he can give a noncircular proof of this fact. Thus his inability to provide such a proof does not nullify the rationality of his belief. But although he is rational in retaining his Christian belief, the Christian in such circumstances is at a complete loss as to how to show his non-Christian friend that he is correct and that his friend is wrong in his respective beliefs.
[Footnote 25: William Alston, "Religious Diversity and Perceptual Knowledge of God," Faith and Philosophy 5, no. 4 (1988): 442-43.]
How is one to break this deadlock? Alston answers that the Christian should do whatever he can to search for common ground on which to adjudicate the crucial differences between their competing views, seeking to show in a noncircular way which of them is correct. If, by proceeding on the basis of considerations that are common to both parties, such as sense perception, rational self-evidence, and common modes of reasoning, the Christian can show that his own beliefs are true and those of his non-Christian friend false, then he will have succeeded in showing that the Christian is in the better epistemic position for discerning the truth about these matters. Once apologetics is allowed to enter the picture, the objective difference between their epistemic situations becomes crucial, for since the non-Christian only thinks he has a self-authenticating experience of God, when in fact he does not, the power of the evidence and argument may, by God's grace, crack his false assurance of the truth of his faith and persuade him to place his faith in Christ.
The task of showing that Christianity is true involves the presentation of sound and persuasive arguments for Christian truth claims. Accordingly, we need to ask ourselves how it is that one proves something to be true. A statement or proposition is true if and only if it corresponds to reality--that is to say, reality is just as the statement says that it is. Thus, the statement "The Cubs won the 1993 World Series" is true if and only if the Cubs won the 1993 World Series. In order to prove a proposition to be true, we present arguments and evidence which have that proposition as the conclusion. Such reasoning can be either deductive or inductive.
In a sound deductive argument, the conclusion follows inevitably from the premises. The two prerequisites of a sound deductive argument are that the premises be true and the logic be valid. If the premises are true but the logic is fallacious, then the argument is invalid. An example of an invalid argument would be:
1) If God exists, objective moral values exist.
2) Objective moral values exist.
3) Therefore, God exists.
Although both the premises are true, the conclusion does not follow logically from them, because the argument commits the fallacy known as "affirming the consequent." On the other hand, an argument can be logically valid but still unsound, because it has false premises. An example of such an unsound argument would be:
1) If Jesus were not Lord, he would be a liar or a lunatic.
2) Jesus was neither a liar nor a lunatic.
3) Therefore, Jesus is Lord.
This is a valid argument, inferring the negation of the first premise's antecedent based on the negation of its consequent. But the argument is still unsound, because the first premise is false: there are other, better alternatives, for example, that Jesus as described in the Gospels is a legend. Hence, in presenting a deductive argument for some Christian truth claim we need to be careful to construct arguments which are logically valid and have true premises.
An inductive argument is an argument of which the premises may be true and the logical inferences valid but the conclusion still be false. In such reasoning the evidence and rules of inference are said to "underdetermine" the conclusion; that is to say, they render the conclusion plausible or likely, but do not guarantee its truth. For example, a sound inductive argument would be:
1) Groups A, B, and C were composed of similar persons suffering from the same disease.
2) Group A was administered a certain new drug, group B was administered a placebo, and group C was not given any treatment.
3) The rate of death from the disease was subsequently lower in group A by 75 percent in comparison with both groups B and C.
4) Therefore, the new drug is effective in reducing the death rate from said disease.
The conclusion is quite likely true based on the evidence and rules of inductive reasoning, but it is not inevitably true; maybe the people in group A were just lucky or some unknown variable caused their improvement.
Although inductive reasoning is part and parcel of everyday life, the description of such reasoning is a matter of controversy among philosophers. One way of understanding inductive reasoning is by means of the probability calculus. Probability theorists have formulated various rules for accurately calculating the probability of particular statements or events given the truth or occurrence of certain other statements or events. Such probabilities are called conditional probabilities and are symbolized Pr (A.B). This is to be read as the probability of A on B, or A given B, where A and B stand for particular statements or events. Probabilities range between 0 and 1, with 1 representing the highest and 0 the lowest probability. Thus, a value ].5 indicates some positive probability of a statement or event and [.5 some improbability, while .5 would indicate a precise balance between the two.
Many of the typical cases of inductive reasoning involve inferences from sample cases to generalizations--for example, the probability of Jones's contracting lung cancer given that he is a smoker--and so have greater relevance to scientific than to philosophical concerns. Still a philosophical or theological position can constitute a hypothesis, and that hypothesis can be argued to be more probable than not, or more probable than a particular competing hypothesis, given various other facts taken as one's evidence. In such cases, the apologist may have recourse to Bayes' Theorem, which lays down formulas for calculating the probability of a hypothesis (H) on given evidence (E).
One form of Bayes' Theorem is the following: