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Faith & Reason: Alvin Plantinga

The last years have seen a remarkable series of letters and encyclicals from Pope John Paul II. The most remarkable, in my opinion, is Salvifici Doloris ("The Christian Meaning of Human Suffering"), published in 1984—surely one of the finest documents (outside the Bible) ever written on this topic, and surely required reading for anyone interested in the so-called problem of evil, or the problems that suffering can pose for the Christian spiritual life or, more generally, the place of suffering in the life of the Christian. Last fall the pope issued another in the series: Fides et Ratio ("Faith and Reason"). This one doesn't strike me as having the sheer depth and power of Salvifici; and perhaps its message is also a little blurred, hard to get completely in focus. Nevertheless, from any seriously Christian point of view—Protestant as well as Catholic—it contains a great deal of solid good sense; and it also provides a wonderful occasion for rethinking its topic. I don't know how much of this document the pope himself wrote; given his philosophical proclivities and background, though, his own personal contribution could be extensive. For present purposes, I'll assume that he substantially wrote the document, an assumption that is encouraged by the use of the first person singular through out. While the letter is officially addressed "to the bishops of the Catholic Church," it seems, in fact, to be addressed much more broadly: to Catholic theologians and philosophers certainly, but also to Catholics and perhaps Christians generally and, in deed, to philosophers generally, whether Christian or not. The letter is divided into seven chapters (plus an in troduction and conclusion) and into 108 sections; I'll refer to specific passages by section.


The central topic is the age-old and never-finished discussion of the relation between faith and reason.1 In any event, it is an ancient topic that goes all the way back to the very beginnings of the Christian religion. But while it is an ancient topic, it is also a crucial current topic; there is no topic, it seems to me, more important for the present-day Christian community than this, and none that warrants more of our best thought and attention.

What the pope proposes here is very much in line with a traditional Catholic answer to the relevant questions, an answer that one attributes to Thomas Aquinas (subject to contradiction by scholars, such being the penalty for attributions to Aquinas, to adapt a phrase of Willard Van Orman Quine). The basic idea is that faith and reason are two separate sources of justified or warranted belief: "there exists a knowledge which is peculiar to faith, surpassing the knowledge proper to human reason, which nevertheless by its nature can discover the Creator" (8); "There exists a twofold order of knowledge, distinct not only as regards their source, but also as regards their object" (9). Reason, as you might expect, is just the human faculty whereby we know what we know in science and everyday life; and faith is a supernatural gift that essentially involves trusting God and believing his Revelation to us through the Bible and the (Roman Catholic) Church. The basic idea is that faith and reason are in harmony. The pope mentions several times what he calls "the unity of truth," the idea that no truth of reason can contradict a truth of faith. That much is truistic: no truth of any kind can contradict any truth of any kind. What is not truistic is the pope's further claim: since God is the author both of faith and of our reason, God would not bring it about or permit it to be that faith and reason were in conflict. "It is the one and the same God who establishes and guarantees the intelligibility and reasonableness of the natural order of things upon which scientists confidently depend, and who reveals himself as the Father of our Lord Jesus Christ" (34). "Both the light of reason and the light of faith come from God … ; hence there can be no contradiction between them" (43). The thought is that God would not permit any deliverance of faith to be inconsistent with any deliverance of reason.

The two are in harmony, therefore, but each has its own sphere: "Philosophy and the sciences function within the order of natural reason; while faith, enlightened and guided by the Spirit, recognizes in the message of salvation the 'fullness of grace and truth'" (9). It is the province of reason and philosophy, says the pope, to ask the great questions associated with the meaning of life: what is our place in the universe? how shall we think about human suffering? in what does shalom or human flourishing consist? In older terminology, what is the chief end of man? It is also the province of philosophy to try to answer these questions, but to do so without adverting to the content of faith.

Philosophy is a purely rational subject. That is not merely to deny that it is irrational (a denial those acquainted mainly with contemporary French philosophy may be pardoned for viewing with a bit of skepticism); it is rather to say that in philosophy one properly relies on reason alone, not employing any of the deliverances of faith. In philosophy, you abstract from what you know or think you know by faith; if you employ what you know by faith (e.g., some of the specific teachings of Christianity) in addressing a problem, the result of the inquiry will not be philosophy but theology.

The pope doesn't say so here, but the Thomistic reason for observing this distinction is that (so the thought goes) to know or believe something by way of faith is to know or believe it on the basis of someone else's say-so, testimony; but what you learn for yourself, by way of reason, is something you "know better," something that has more epistemic clout, a higher kind of epistemic status, for you than what you believe on the authority of someone else (even God). For example, if I believe the Fundamental Theorem of the Calculus on the authority of my mathematician friend Paul, I don't know it as well as if I learn the appropriate bit of mathematics and come myself to see how the proof goes. (But isn't this doubtful? Given my mathematical limitations and my dubious grasp of the proof, perhaps I'd be better off believing on Paul's authority.)

Furthermore, according to John Paul, reason can go a considerable distance toward answering these questions: for example, it can prove the existence of God. Perhaps it can't prove the central claims of Christianity—for Sin, In carnation, Atonement, Redemption we need faith—but it can prove the existence of God, and that's no mean feat. And while we need faith for Incarnation and Atonement, this faith in no way contradicts reason. In fact, says John Paul, faith fulfills reason; I think he means that a person who didn't know about the gospel but thought very hard and responsibly about those topics (some of the ancient philosophers, say) and then came to hear the gospel, could or would see that what the gospel proposes is what he was really looking for all along. The Church Fathers, he says, "succeeded in disclosing completely all that remained implicit and preliminary in the thinking of the great philosophers of antiquity" (41). "Illumined by faith," furthermore, "reason is set free from the fragility and limitations deriving from the disobedience of sin and finds the strength required to rise to the knowledge of the Triune God" (43). Faith and reason, then, though two quite different sources of warranted belief, are wholly harmonious. Faith fulfills reason, and reason is the organon by which faith comes to understand itself.

This is the basic teaching on the topic of faith and reason, and, as I say, it is clearly continuous with traditional Catholic thought. Why then does the Pope take up these topics at present; why does he feel compelled or called to write this letter now? Because, of course, he sees a present need for the reiteration of these teachings; and the need arises because at present these teachings are widely flouted, or ignored, or contradicted. Perhaps the most pressing problem, from the pope's point of view, is a loss of confidence in reason, a stance in which he sees a kind of false modesty, a vice masquerading as a virtue. This deplorable line of thought manifests itself in many different ways, and in theology, history, literary studies, and Western culture generally, not just in philosophy.

Here the pope quite properly notes a distressing tendency, on the part of many so-called postmodern thinkers. They often seem to leap lightly from the thought that human beings cannot easily arrive at the truth, that there are no methods or algorithms that can guarantee reason that she will arrive at the truth, to the vastly different and vastly more portentous (and pretentious) claim that there simply isn't any such thing as truth. Much of the letter is taken up with advice to philosophers: accept the help offered by divine revelation, and don't lose faith in reason. There is also advice to theologians: again, don't lose faith in reason; don't be blown about by every philosophical wind of doctrine; don't uncritically run after the latest philosophical fad; but be very serious about philosophy ("I cannot fail to note with surprise and displeasure that this lack of interest in the study of philosophy is shared by not a few theologians" [61]). The rest of us Christians can only applaud the pope's strictures on the postmodern irrationalism running (or, to avoid exaggeration, jogging) riot through the humanities. His advice to theologians also seems to me particularly apposite; but then, as a philosopher, I could be expected to think that.


This is a long letter, and of course there is a lot more to it than the bare bones summary I have given. The bare bones summary will have to suffice, however; and in what follows I would like to make a couple of comments on the pope's suggestions.

A. Non-Christian philosophy: First, a fairly standard Reformed comment on what the pope apparently sees as the relation between philosophy and the Christian faith. As we saw above, he thinks of natural reason as an ensemble of powers or capacities we have just by virtue of the way we were created by God. With the Fall, certain supernatural gifts were lost; but natural reason was substantially unaffected. These powers, furthermore, can take us a good way with respect to answering those great questions of the meaning of life. The ancient philosophers—perhaps, in particular, Plato and Aristotle—were able by virtue of reason to move some significant distance toward the whole Christian truth. Furthermore, divine revelation, which is, of course, necessary for the final steps, can be seen to fulfill reason in the sense that it is in continuity with their thought, and actually provides what they were groping for.

Now, perhaps it is not unreasonable to think of the matter this way in connection with ancient philosophy (but even here, aren't there Democritus and Lucretius as well as Plato and Aristotle, and isn't the Cross "foolishness to the Greeks"?). Once we come to modern philosophy, however, with post-Kantian and post-Humean turning away from Christian or even theistic belief, doesn't it look as if much of philosophy is less an incomplete approach to Christian belief than arrogant apostasy? One branch of this apostasy culminates in the philosophical naturalism dominating most of the most important con temporary American philosophy departments, a naturalism that explicitly rejects not just Christian truth but theism generally. The other branch perhaps culminates in Friedrich Nietzsche's subtle and modulated observations that God is dead, and that Christian belief both fosters and arises from a sort of sniveling, servile, cowardly, evasive, duplicitous, and all-around contemptible sort of character that is at the same time envious, self-righteous, and full of hate disguised as charitable kindness. (Not a pretty picture.) Neither group is best seen as making an approach to Christian truth but just falling a bit short.

What the Catholic view neglects here, according to this Reformed rejoinder, is the fact that non-Christian philosophy is not merely handicapped by the "inherent weakness of human reason" (75); it is rather that philosophers, like humanity generally, are fallen, and in need of conversion. Much of philosophy is a categorical renunciation of Christian belief, and an attempt to work out a view of the world wholly incompatible with that of Christian theism. Contemporary philosophy doesn't look at all like an incomplete approximation to Christian truth; nor is it the case that contemporary philosophers, if they heard the gospel, would see that this is really what they were looking for all along. Instead (so it seems to me), much contemporary philosophy is a development and elaboration of a view of the world (and indeed, a view of the world that is at bottom religious) that is antithetical to Christianity. Thus it is less a deliverance of reason than the articulation of a rival faith.

Permit me to elaborate. Contemporary philosophy is a vast and variegated affair, but perhaps it is possible to introduce some order by noting that there are really three basic kinds of world-views on offer at present and in the West. (Of course, there are also various combinations of them.) First, there is Christian theism together with various approximations to it. Second, there is naturalism, where the basic idea is that there is no such person as God,2 and human beings must be understood, not in terms of their being image bearers of God, but in terms of their evolutionary origin. Naturalism is extremely popular at the moment; just about every other issue of the New York Review of Books carries a review of another book intended to interpret ourselves to ourselves along these lines. A recent high point is a book in which a new understanding of religion is proposed: at a certain point in our evolutionary history we human beings made the transition from being prey to being predators, and religion arose as a celebration of that happy moment! (But wouldn't you think we would have needed religion even more when we were still prey?) Prime contemporary examples of naturalists among philosophers would be W. V. O. Quine and Daniel Dennett,3 and, at a much deeper and more subtle level, David Lewis.

Third, there is what the pope calls Nihilism, or antirealism with respect to truth, or relativism, which at bottom is the idea that there really isn't any such thing as truth. While naturalism dominates philosophy in America, antirealism is rampant in various areas of the humanities, such as literary studies, film studies, studies in continental philosophy, and to some degree, in history. This popular but lamentable way of thinking begins in Immanuel Kant's idea that (not God, but) we human beings are somehow responsible for the basic structure of the world we live in; it progresses through the thought that we all make our own worlds, to the culminating conclusion that there really isn't any such thing as the way things are. There is only my version, your version, and so on—my interpretation, your interpretation, but no reality that these interpretations are interpretations of. (It's interpretation all the way down.) Those who accept this view usually capitalize the initial t of truth, claiming that what they reject is Truth with a capital T (whatever that is); they then offer pale and ghostly and sometimes silly substitutes for truth.

A paradigm would be Richard Rorty (although his voice is only one among many), with his suggestion that truth is really something like what your peers will let you get away with saying. (Then, just as sophomore students tell us, a proposition might be true for me but false for you; disagreeable fellow that I am, my peers won't let me get away with saying things your peers don't mind your saying.) We might note ambulando that this way of thinking has interesting moral possibilities: if you have done something wrong, lie about it; try to get your peers to let you get away with saying you didn't do it. If you succeed, then it will be true that you didn't do it, in which case you won't have done it; furthermore, as an added bonus, you won't even have lied about it! No doubt you can see further interesting possibilities for dealing with war, poverty, disease, and the other ills our flesh is heir to. Antirealism with respect to truth is carrying to its illogical conclusion the modern insistence upon human autonomy. In deed, the trouble with truth, says Rorty, is that it limits one's possibilities for self-redefinition. After all, it is only my allegiance to truth that prevents me from redefining myself as a Nobel Prize-winning chemist, or a world-class tenor, or a premier NFL running back.

Now, in this connection it seems as if the pope sometimes addresses philosophers generally (not just Catholic or Christian philosophers) as if they were something like confused Catholics, Catholics who have overlooked or forgotten about the proper relation between faith and reason. But naturalists and relativists, philosophers like Quine or Dennett or Derrida or Rorty, are not confused Catholics. They are unlikely to be swayed by the pope's appeal; they have no allegiance to Catholic, or Christian, or theistic belief, and will not be at all likely to accept advice based on a Christian view of faith and reason. Nor is it the case that if they heard the gospel, they would see it as the fulfillment of what they were looking for all along. In deed, nearly all of them have heard the gospel—most, I suppose, were brought up as Christians of one sort or another—and have rejected it. Instead, they are working out the implications of a way of looking at the world, a way wholly incompatible with Christian theism.

So one sort of comment on the document: it underestimates the place of sin, apostasy, rejection of Christian truth in non-Christian philosophy. It isn't that the result of sin, with respect to our intellectual capacities, is just that we lost a supernatural addition to our natural faculties, those natural faculties themselves functioning more or less as be fore. It is rather that (a) our natural faculties them selves suffered substantially from the results of sin, so that our ability to know ourselves, others, and God has been damaged, and that (b) by virtue of our corruption, we are inclined to set ourselves against God. Part of the latter is working out views of the world in explicit opposition to Christian truth.

B. Christian philosophy: A second Reformed comment addresses the nature of Christian philosophy. The pope is a doughty defender of philosophy, being himself a philosopher, and he mentions a large number of important and impressive Catholic philosophers of the last decades. (He doesn't mention the remarkable work in Christian philosophy done by Protestants over the last generation or so, partly because of the geographical distance between Rome and North America, where most of it has been going on, and partly, no doubt, because of the theological distance between Rome and Geneva.) But what, according to John Paul, is Christian philosophy? We have already seen the main point: whatever precisely it is, philosophy—including Christian philosophy—is a purely ration al discipline with no input from faith: "We see here philosophy's valid aspiration to be an autonomous enterprise, obeying its own rules and employing the powers of reason alone" (75). But then what distinguishes Christian philosophy from just any old kind of philosophy?

Following Etienne Gilson and others, the pope suggests that Christian philosophy is philosophy that receives a certain help from faith, help of two kinds. First, faith functions as a sort of error detector: the Christian philosopher knows she's gone wrong, in following out a line of thought or an argument, if she encounters a proposition that is incompatible with Christian faith. Then she knows she's made a mistake somewhere and must go back and check her work. And second, faith can suggest topics for philosophical work to the philosopher: perhaps among the things that she believes by faith, there are some that she can prove by reason; the result of such effort would be Christian philosophy. "Revelation clearly proposes certain truths which might never have been discovered by reason unaided, al though they are not of themselves inaccessible to reason" (76).

Now Gilson calls the view just outlined the Thomist view and notes that "Augustinians," as he calls them (and many Protestants would be among these Augustinians), see matters a bit differently. First, they might be doubtful that everything one proves for oneself has more epistemic clout than anything one believes on the basis of testimony. It is only by testimony that I so much as know my name (my birth certificate is just more testimony); but don't I know this "better," so to speak, than some complex theorem of mathematics for which I can produce what is at best a shaky proof?

More important, the Augustinian would think it perfectly appropriate, in philosophy, to appeal to what she knows by way of faith. Philosophy is a matter of faith seeking understanding, sure enough: but this need not proceed by trying to offer a proof of the item of faith in question from purely rational premises. Another way to seek understanding is to ascertain the relation of the proposition in question to other items of the faith, and to what one knows by way of reason; and still another way to increase understanding here is to see what the faith implies or entails with respect to the sorts of questions philosophers ask and answer. So the Augustinian (and Protestant) philosopher might ask such questions as this: what does Christian faith imply with respect to the nature of human beings, of knowledge, of the good, of causation, of natural laws, or morality, of universals, propositions, sets, possible worlds, and a thousand other topics? Suppose I come to hold a certain philosophical view by virtue of some argument one essential premise of which comes from faith: that doesn't mean, says the Augustinian, that my conclusion is theology rather than philosophy. It is properly thought of as philosophy because it is an answer to one of the questions philosophers ask and answer, even if my answer is essentially dependent upon faith.

The Thomist, as we have seen, will regard my answer as theology rather than philosophy just because it wasn't reached on the basis of reason alone but depended upon a premise from faith. But maybe here we can propose an irenic compromise. Let's agree that the Thomist is right: any proposition I believe, even on specifically philosophical topics, which is such that my reasons for holding it include propositions from the faith, is for me not philosophy but theology. But now consider the project of figuring out the best way to think about a given topic—the nature of causality, say, or any other of the above topics—given the truth of Christian faith. We could put the project like this: you say to yourself, "Suppose Christian faith were true—I'm not saying for present purposes whether it is or isn't—but suppose it were: then what would be the right way to think about causality?" The result of your inquiry would be conditional: If Christian faith is true, then this is the right or best or anyway a good way to think about causality. You don't, in pursuing this inquiry, assert that the Christian faith is true; you only explore its consequences. And in this exploration (in figuring out that conditional), you would, of course, use just reason, not faith; you don't employ as premises anything you know by faith. From the Thomist point of view, therefore, working at those conditionals will be philosophy rather than theology; for you don't at any point accept as a premise any of the deliverances of the faith; all your premises come from reason alone.

Now both Augustinian and Thomist will as Christians assert the antecedent (the Christian faith is true) and hence also the consequent (the right way to think about causality is thus and so); but the Thomist will hold that in asserting that consequent, he and the Augustinian are really doing theology and not philosophy. Well, OK, says the Augustinian; let's concede that; the important thing is that philosophers should think about those conditionals that relate the Christian faith to the various areas of philosophy. There is little need to argue about whether asserting their consequents is philosophy or theology. Call it what you like; what counts is that philosophers, and others, work out those conditionals. This irenic proposal should give the Thomist all he wants: Christian philosophy is working at those conditionals, and doing so is strictly a rational procedure. But it also gives the Augustinian all, or almost all (enough, anyway), of what she wants: it is the philosopher's job to figure out what the bearing of faith is on these great questions of philosophy.

So Protestants—at any rate, those with Reformed proclivities—will find some things in this encyclical with which they may be in less than enthusiastic agreement. Overall, however, they will (or should) regard both the pope and Catholics generally as brothers and sisters in Christ—and as wonderful allies in precisely these areas of responding to contemporary non-Christian philosophy, and working out Christian answers to the questions philosophers ask. We Catholic and Protestant and Orthodox Christians now, as opposed, perhaps, to 400 years ago, have real enemies in the world, and common enemies; we do not need to fight each other. We must make common cause with these fellow Christians, and perhaps especially common cause in the world of philosophy and the intellectual life in general.4

Alvin Plantinga is John A. O'Brien Professor of Philosophy and director of the Center of Philosophy of Religion at the University of Notre Dame. An anthology of his work, The Analytic Theist: An Alvin Plantinga Reader, edited by James F. Sennett, has recently been published by Eerdmans, and the concluding volume of his trilogy on warrant is forthcoming from Oxford University Press.

  1. The encyclical is also to some extent aimed at a quite distinct topic: the relation between Christ and culture. I believe it is crucial to see that these two questions are distinct questions. In my opinion, they are insufficiently distinguished in this document. (Perhaps some will see here a Catholic/Protestant difference.)
  2. This is ontological naturalism; another variant is epistemic naturalism, where the idea is that science really tells us all there is to know (and one thing science definitely does not tell us is that there is such a person as God).
  3. See his Darwin's Dangerous Idea, and see my "Dennett's Dangerous Idea: Darwin, Mind and Meaning," BOOKS & CULTURE May/June 1996.
  4. My thanks to the members of the Notre Dame Center for Philosophy of Religion colloquium.

Other pages in our "Faith & Reason" section:

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