Whatever beliefs are, none of us harbors an infinite number of them.18 While philosophers may doubt whether beliefs are the sort of thing that can be counted, it is clear that we have a finite amount of storage in our brains,19 a finite number of discrete memories, and a finite vocabulary that waxes and wanes somewhere well shy of 100,000 words. There is a distinction to be made, therefore, between beliefs that are causally active20 -i.e., those that we already have in our heads-and those that can be constructed on demand. If believing is anything like perceiving, it is obvious that our intuitions about how many of our beliefs are present within us at any given moment might be unreliable. Studies of "change blindness," for instance, have revealed that we do not perceive nearly as much of the world as we think we do, since a large percentage of the visual scene can be suddenly altered without our noticing.21 An analogy with computer gaming also seems apropos: current generations of computer games do not compute parts of their virtual world until a player makes a move that demands their existence.22 Perhaps many of our cognitive commitments are just like this.23
Whether most of what we believe is always present within our minds or whether it must be continually reconstructed, it seems that many beliefs must be freshly vetted before they can guide our behavior. This is demonstrated whenever we come to doubt a proposition that we previously believed, Just consider what it is like to forget the multiplication table-12 x 7 = ? All of us have had moments when 84 just didn't sound quite right. At such times, we may be forced to perform some additional calculations before we can again be said to believe that 12x7 = 84. Or consider what it is like to fall into doubt over a familiar person's name ("Is his name really Jeff? Is that what I call him?"). It is clear that even very well-worn beliefs can occasionally fail to achieve credibility in the present. Such failures of truth testing have important implications, to which we now turn.
A Matter of True and False
Imagine that you are having dinner in a restaurant with several old friends. You leave the table briefly to use the restroom, and upon your return you hear one of your friends whisper, "Just be quiet. He can't know about any of this."
What are you to make of this statement? Everything turns on whether you believe that you are the "he" in question. If you are a woman, and therefore excluded by this choice of pronoun, you would probably feel nothing but curiosity. Upon retaking your seat, you might even whisper, "Who are you guys talking about?" If you are a man, on the other hand, things have just gotten interesting. What secret could your friends be keeping from you? If your birthday is just a few weeks away, you might assume that a surprise party has been planned in your honor. If not, more Shakespearean possibilities await your consideration.
Given your prior cognitive commitments, and the contextual cues in which the utterance was spoken, some credence-granting circuit inside your brain will begin to test a variety of possibilities. You will study your friends' faces. Are their expressions compatible with the more nefarious interpretations of this statement that are now occurring to you? Has one of your friends just confessed to sleeping with your wife? When could this have happened? There has always been a certain chemistry between them.... Suffice it to say that whichever interpretation of these events becomes a matter of belief for you will have important personal and social consequences.
At present, we have no understanding of what it means, at the level of the brain, to say that a person believes or disbelieves a given proposition-and yet it is upon this difference that all subsequent cognitive and behavioral commitments turn. To believe a proposition we must endorse, and thereby become behaviorally susceptible to, its representational content. There are good reasons to think that this process happens quite automatically-and, indeed, that the mere comprehension of an idea may be tantamount to believing it, if only for a moment. The Dutch philosopher Spinoza thought that belief and comprehension were identical, while disbelief required a subsequent act of rejection. Some very interesting work in psychology bears this out.24 It seems rather likely that understanding a proposition is analogous to perceiving an object in physical space. Our default setting may be to accept appearances as reality until they prove to be otherwise. This would explain why merely entertaining the possibility of a friend's betrayal may have set your heart racing a moment ago.
Whether belief formation is a passive or an active process, it is clear that we continuously monitor spoken utterances (both our own and those of others) for logical and factual errors. The failure to find such errors allows us to live by the logic of what would otherwise be empty phrases. Of course, even the change of a single word can mean the difference between complaisance and death-defying feats: if your child comes to you in the middle of the night saying, "Daddy, there's an elephant in the hall," you might escort him back to bed toting an imaginary gun; if he had said, "Daddy, there's a man in the hall," you would probably be inclined to carry a real one.
Faith and Evidence
It does not require any special knowledge of psychology or neuro-science to observe that human beings are generally reluctant to change their minds. As many authors have noted, we are conservative in our beliefs in the sense that we do not add or subtract from our store of them without reason. Belief, in the epistemic sense-that is, belief that aims at representing our knowledge about the world-requires that we believe a given proposition to be true, not merely that we wish it were so. Such a constraint upon our thinking is undoubtedly a good thing, since unrestrained wishful thinking would uncouple our beliefs from the regularities in the world that they purport to represent. Why is it wrong to believe a proposition to be true just because it might feel good to believe it? One need only linger over the meaning of the word "because" (Middle English "by" + "cause") to see the problem here. "Because" suggests a causal connection between a proposition's being true and a person's believing that it is. This explains the value we generally place on evidence: because evidence is simply an account of the causal linkage between states of the world and our beliefs about them. ("I believe Oswald shot Kennedy because I found his fingerprints on the gun, and because my cousin saw him do it, and my cousin doesn't lie.") We can believe a proposition to be true only because something in our experience, or in our reasoning about the world, actually speaks to the truth of the proposition in question.25
Let's say that I believe that God exists, and some impertinent person asks me why. This question invites-indeed, demands-an answer of the form "I believe that God exists because..." I cannot say, however, "I believe that God exists because it is prudent to do so" (as Pascal would have us do). Of course, I can say this, but I cannot mean by the word "believe" what I mean when I say things like "I believe that water is really two parts hydrogen and one part oxygen because two centuries of physical experiments attest to this" or "I believe there is an oak in my yard because I can see it." Nor can I say things like "I believe in God because it makes me feel good." The fact that I would feel good if there were a God does not give me the slightest reason to believe that one exists. This is easily seen when we swap the existence of God for some other consoling proposition. Let's say that I want to believe that there is a diamond buried somewhere in my yard that is the size of a refrigerator. It is true that it would feel uncommonly good to believe this. But do I have any reason to believe that there is actually a diamond in my yard that is thousands of times larger than any yet discovered? No. Here we can see why
Pascal's wager, Kierkegaard's leap of faith, and other epistemological ponzi schemes won't do. To believe that God exists is to believe that I stand in some relation to his existence such that his existence is itself the reason for my belief. There must be some causal connection, or an appearance thereof, between the fact in question and my acceptance of it. In this way, we can see that religious beliefs, to be beliefs about the way the world is, must be as evidentiary in spirit as any other.
The moment we admit that our beliefs are attempts to represent states of the world, we see that they must stand in the right relation to
the world to be valid. It should be clear that if a person believes in God because he has had certain spiritual experiences, or because the Bible makes so much sense, or because he trusts the authority of the church, he is playing the same game of justification that we all play when claiming to know the most ordinary facts. This is probably a conclusion that many religious believers will want to resist; but resistance is not only futile but incoherent. There is simply no other logical space for our beliefs about the world to occupy. As long as religious propositions purport to be about the way the world is- God can actually hear your prayers, If you take his name in vain bad things will happen to you, etc.-they must stand in relation to the world, and to our other beliefs about it. And it is only by being so situated that propositions of this sort can influence our subsequent thinking or behavior. As long as a person maintains that his beliefs represent an actual state of the world (visible or invisible; spiritual or mundane), he must believe that his beliefs are a consequence of the way the world is. This, by definition, leaves him vulnerable to new evidence. Indeed, if there were no conceivable change in the world that could get a person to question his religious beliefs, this would prove that his beliefs were not predicated upon his taking any state of the world into account. He could not claim, therefore, to be representing the world at all.26
Although many things can be said in criticism of religious faith, there is no discounting its power. Millions among us, even now, are quite willing to die for our unjustified beliefs, and millions more, it seems, are willing to kill for them. Those who are destined to suffer terribly throughout their lives, or upon the threshold of death, often find consolation in one unfounded proposition or another. Faith enables many of us to endure life's difficulties with an equanimity that would be scarcely conceivable in a world lit only by reason. Faith also appears to have direct physical consequences in cases where mere expectations, good or bad, can incline the body toward health or untimely death.27 But the fact that religious beliefs have a great influence on human life says nothing at all about their validity. For the paranoid, pursued by persecutory delusions, terror of the CIA may have great influence, but this does not mean that his phones are tapped.
What is faith, then? Is it something other than belief? The Hebrew term 'emund (verb 'ran) is alternately translated as "to have faith," "to believe," or "to trust." The Septuagint, the Greek translation of the Hebrew Bible, retains the same meaning in the term pisteuein, and this Greek equivalent is adopted in the New Testament. Hebrews 11:1 defines faith as "the assurance of things hoped for, the conviction of things not seen." Read in the right way, this passage seems to render faith entirely self-justifying: perhaps the very fact that one believes in something which has not yet come to pass ("things hoped for") or for which one has no evidence ("things not seen") constitutes evidence for its actuality ("assurance"). Let's see how this works: I feel a certain, rather thrilling "conviction" that Nicole Kidman is in love with me. As we have never met, my feeling is my only evidence of her infatuation. I reason thus: my feelings suggest that Nicole and I must have a special, even metaphysical, connection-otherwise, how could I have this feeling in the first place? I decide to set up camp outside her house to make the necessary introductions; clearly, this sort of faith is a tricky business.
Throughout this book, I am criticizing faith in its ordinary, scriptural sense-as belief in, and life orientation toward, certain historical and metaphysical propositions. The meaning of the term, both in the Bible and upon the lips of the faithful, seems to be entirely unambiguous. It is true that certain theologians and contemplatives have attempted to recast faith as a spiritual principle that transcends mere motivated credulity. Paul Tillich, in his Dynamics of Faith (1957), rarefied the original import of the term out of existence, casting away what he called "idolatrous faith" and, indeed, all equations between faith and belief. Surely other theologians have done likewise. Of course, anyone is free to redefine the term "faith" however he sees fit and thereby bring it into conformity with some rational or mystical ideal. But this is not the "faith" that has animated the faithful for millennia. The faith that I am calling into question is precisely the gesture that Tillich himself decried as "an act of knowledge that has a low degree of evidence." My argument, after all, is aimed at the majority of the faithful in every religious tradition, not at Tillich's blameless parish of one.
Despite the considerable exertions of men like Tillich who have attempted to hide the serpent lurking at the foot of every altar, the truth is that religious faith is simply unjustified belief in matters of ultimate concern-specifically in propositions that promise some mechanism by which human life can be spared the ravages of time and death. Faith is what credulity becomes when it finally achieves escape velocity from the constraints of terrestrial discourse-constraints like reasonableness, internal coherence, civility, and candor. However far you feel you have fled the parish (even if you are just now adjusting the mirror on the Hubble Space Telescope), you are likely to be the product of a culture that has elevated belief, in the absence of evidence, to the highest place in the hierarchy of human virtues. Ignorance is the true coinage of this realm-"Blessed are those who have not seen and have believed" (John 20:29)-and every child is instructed that it is, at the very least, an option, if not a sacred duty, to disregard the facts of this world out of deference to the God who lurks in his mother's and father's imaginations.
But faith is an impostor. This can be readily seen in the way that all the extraordinary phenomena of the religious life-a statue of the Virgin weeps, a child casts his crutches to the ground-are seized upon by the faithful as confirmation of their faith. At these moments, religious believers appear like men and women in the desert of uncertainty given a cool drink of data. There is no way around the fact that we crave justification for our core beliefs and believe them only because we think such justification is, at the very least, in the offing. Is there a practicing Christian in the West who would be indifferent to the appearance of incontestable physical evidence that attested to the literal truth of the Gospels? Imagine if carbon dating of the shroud of Turin28 had shown it to be as old as Easter Sunday, AD 29: Is there any doubt that this revelation would have occasioned a spectacle of awe, exultation, and zealous remission of sins throughout the Christian world?
This is the very same faith that will not stoop to reason when it has no good reasons to believe. If a little supportive evidence emerges, however, the faithful prove as attentive to data as the damned. This demonstrates that faith is nothing more than a willingness to await the evidence-be it the Day of Judgment or some other downpour of corroboration. It is the search for knowledge on the installment plan: believe now, live an untestable hypothesis until your dying day, and you will discover that you were right.
But in any other sphere of life, a belief is a check that everyone insists upon cashing this side of the grave: the engineer says the bridge will hold; the doctor says the infection is resistant to penicillin-these people have defeasible reasons for their claims about the way the world is. The mullah, the priest, and the rabbi do not. Nothing could change about this world, or about the world of their experience, that would demonstrate the falsity of many of their core beliefs. This proves that these beliefs are not born of any examination of the world, or of the world of their experience. (They are, in Karl Popper's sense, "unfalsifiable.") It appears that even the Holocaust did not lead most Jews to doubt the existence of an omnipotent and benevolent God. If having half of your people systematically delivered to the furnace does not count as evidence against the notion that an all-powerful God is looking out for your interests, it seems reasonable to assume that nothing could. How does the mullah know that the Koran is the verbatim word of God? The only answer to be given in any language that does not make a mockery of the word "know" is- he doesn't.
A man's faith is just a subset of his beliefs about the world: beliefs about matters of ultimate concern that we, as a culture, have told him he need not justify in the presen
t. It is time we recognized just how maladaptive this Balkanization of our discourse has become. All pretensions to theological knowledge should now be seen from the perspective of a man who was just beginning his day on the one hundredth floor of the World Trade Center on the morning of September 11, 2001, only to find his meandering thoughts-of family and friends, of errands run and unrun, of coffee in need of sweetener-inexplicably usurped by a choice of terrible starkness and simplicity: between being burned alive by jet fuel or leaping one thousand feet to the concrete below. In fact, we should take the perspective of thousands of such men, women, and children who were robbed of life, far sooner than they imagined possible, in absolute terror and confusion. The men who committed the atrocities of September 11 were certainly not "cowards," as they were repeatedly described in the Western media, nor were they lunatics in any ordinary sense. They were men of faith- perfect faith, as it turns out-and this, it must finally be acknowledged, is a terrible thing to be.