Edward N. Martin, Ph.D.
Trinity College & Seminary, Newburgh, IN
This is a paper about God, evil, and the soul-making theodicy. Too often we pair together this theodicy with various liberal philosophical theologians (e.g. John Hick), and miss the importance of the rich resources that we find in the theodicy itself. I would like to propose that we not overlook the continuing importance of this theodical method, for this method or approach to theodicy seems squarely in line, in its essential parts, with the New Testament conception of the development of Christian character and the theological virtue of hope. Consider Paul’s sentiment in the Book of Romans.
“…we also rejoice in our sufferings, because we know that suffering produces perseverance; perseverance, character; and character, hope.” (Rom 5:3,4 [NIV])
Obviously, for suffering to ultimately produce character and hope for the believer there has to be a structure in place whereby the intrinsic evil of suffering can “produce” this sequential process, from suffering to perseverance to character and finally to hope.
What ought we to say, however, for the unbeliever? Is there a structure in place in the human psyche or the human mind such that suffering can, in some way, produce hope for this person as well? The “hope” in view here need not be true, conscious Christ-focused eschatological hope, or a true instantiation of the theological virtue of hope (which takes knowledge of Christ as personal savior as a necessary condition for obtaining). Although Paul was addressing believing Christians in Romans 5, perhaps there is a sort of “first level” of hope whereby even the unbeliever can get a foretaste or shadow of the true hope which we find in Christ.
Let us examine this possibility by means of an investigation of the structure of our belief-forming mechanisms. Since suffering is what sets this chain of implications in motion of which Paul speaks in Romans 5, we know that suffering therefore plays a key role in this process. It is the door, the gateway, that can lead the human heart and mind ultimately to hope.
I will employ a sort of transcendental approach in this paper, that approach offered by Kant in his first Critique. The transcendental argument-type one may employ would be to observe an X, and to ask: what are the conditions for the possibility of the instantiation of X? The strength of this approach for theodicy is that it allows for two important steps in properly expressing a theodicy. First, the theist is allowed to start with basic knowledge claims that both sides of the debate can agree upon. We might call this set of claims that he starts with “common background knowledge.” Second, it allows the theist to “tell the theodical story” with a goal in mind of supplying sets of plausible or not irrational sufficient conditions for God’s permission of evils. Many theodicists, for example, have started with basic assumptions such as the following:
1. There is a vast amount of evil in the world.
2. Our belief-forming mechanisms are wonderfully complex and exhibit intelligent design.
3. We do note that some evils do patently give rise, once followed out in an historical situation, to a greater good.
4. Some evils, when followed out for a significant space of time, for reasons we cannot perceive do not patently give rise to an observational greater good.
What are some sets of sufficient conditions that could, or might, plausibly give rise to worlds in which the above agreed-upon realities are true?
In order to begin here to answer this question, let us look at the framework within which the soul-making theodicy is usually given. It is clear that the theist must include, as part of his presentation, a good bit of ethical theory by which to explain and help understand God’s duties as a creator, the definition of virtue, suffering as a possible extrinsic good, and the like. Some recent developments in the area of epistemology are also, I believe, of great relevance to theodicy. Recent work by Alvin Plantinga and others holds that epistemic justification or “warrant” hinges on the idea of the “proper functioning” of one’s cognitive mechanisms in one’s environment at a time, in the absence of significant epistemic defeaters, overriders or undercutters. If we form a belief in a circumstance, such as “my shoe is on fire,” and we are lead to believe this by means of possession of a properly functioning belief-forming apparatus (our minds), which functions according to a “design plan,” and those minds are functioning within the environment in which they are “designed” to function at peak capacity (on Earth, say, rather than in the fiery atmosphere of Alpha Centuri), then we are justified or warranted in that belief, that “my foot is on fire.” (Thankfully, at this time, this is a false belief and one that I rightly do not possess.) The terms I have employed here, “design plan,” “designed,” and the like have been carefully selected so as not to beg the important question of etiology of these epistemic mechanisms. Darwinian evolutionist and theist alike could speak of the “design plan” of a tulip, which might entail the flower’s “way” of reproduction and propagation, its genetic constituents, and whatever teleological (or seeming teleological) systems may be enjoyed by the tulip (such as heliotropism, turning towards the light of the sun during the day, etc.). Evolution might be said to have “designed” such a system. Though strained, I believe this is right, and therefore it does not beg the question to use these terms.
Theists hold that our belief-forming mechanisms are created by God not only to provide us the ability to form true beliefs about ourselves and our environment, but also to lead us, at some opportune moment, to freely believe in Him. Part of Plantinga’s emphasis is to underline the fact that our minds have to be operating in the environment in which He designed the mind to function and achieve peak performance. We may ask: how do our belief-forming mechanisms operate in our environment in such a way that they cooperate with God’s work in our hearts, working as a necessary but not sufficient component for fully human rational thought and consciousness? For obviously there was a time in each of our lives at which we did not believe in God. However, through various experiences and the prodding and effectual call of the Holy Spirit upon our lives, we came to put our trust in God for salvation. It is not irrational to think, but eminently rational, that if our belief-forming mechanisms had not been functioning properly in the past, and were not functioning properly now, we may well have not “seen” God, seen that object for which the properly-functioning mind was designed to “see” (“see” in the sense of “perceive”).
One false conclusion to draw from this last point would be that since unbelievers do not “see” God and have not put their faith and trust in Him, they must not have properly functioning belief-forming mechanisms. But I believe this would be a faulty inference. According to Ephesians 4:23, it is the “spirit of the mind,” not the mind itself, that is renewed in salvation. The spirit or helmsman over the human mind is evidently the will, not the mind itself. With respect to Natural Theology, there have been divisions on this point, e.g., surrounding the issue on what truth the mind of the unbeliever can come to regarding God with the mind alone in its pre-saved state. Augustine claims that
if those who are called philosophers, particularly the Platonists, have said anything which is true and consistent with our faith, we must not reject it, but claim it for our own use, in the knowledge that they possess it unlawfully.
C.S. Lewis, in contradistinction, in the context in which Lord Digory is telling Eustace and Lucy, in The Last Battle (vol 7 of the Narnia series), how this present life is but a shadow of the reality of heaven that is to come, says that this truth is “all in Plato, all in Plato: bless me, what do they teach them at these schools!” The point is that the mind is functioning properly or largely properly in the unbeliever; however, the will is not allowing the evidence of creation, the written Word of God, and the voice of God within, to convict properly and lead to a repentant heart that longs to know and “see” God again and again. What the mind is designed to “see,” the heart is designed to will to desire time and time again. Augustine spoke wisely when he said, in the opening lines of Confessions, that “our hearts find no peace until they rest in you [the Lord].”
The experience I would like to focus on here that gives rise to religious and moral awareness in humans is the experience of pain and suffering. It goes without saying that every human individual has experienced great pain on many occasions in his life, and that pain, among its many useful qualities, has one in particular that makes it perhaps a singularly unique quality. This property is the virtuous property of being able to completely take hold of and sustain our attention until such pain should be eradicated, or the dimensions of the pain are understood. For example, if my wife puts a cool and refreshing drink on my desk while I am not looking, I may leisurely discover the source of this blessing later on in the day. However, if my left big toe is beset with a terrible cramp, I turn all of my attention to eradicate or alleviate this painful condition. Indeed, pain is God’s “megaphone” by which God awakens the soul, again and again, from its dogmatic slumbers.
My claim here would be that part of our “belief-forming mechanisms,” those mechanisms with which God has so outfitted us to form beliefs upon experiencing certain cognitive or psychological states in this life, is the same part which gives rise to an awareness of a state which we might call “exasperation by evil.”
If indeed we are “naturally outfitted,” with our minds so constructed, whether Christian or pagan, when experiencing a sufficiently dreadful evil situation, to give rise to feelings and beliefs of exasperation, then one should conclude that it is therefore “natural” to cry, as the Psalmist did, “How long, O Lord? How long?” (cf. Ps 13:1)
Our belief-forming mechanisms naturally lead us to form such beliefs as these when we experience debilitating or soul-destroying evil.
Suppose we say that when in a pain state, which is sufficiently long-lasting and violent, I form the belief that there is no loving heavenly Father who loves me as a Father loves his children. Call this a “D- ” or “Doubt-belief mechanism,” and the formation of such a belief “D-belief formation.” So far, we are saying that both a Christian and pagan are outfitted to form such a belief by God’s creative activity. So, it is therefore “natural” to form beliefs of doubt, or D-beliefs, concerning God’s existence and the existence of a loving heavenly father who loves us as an earthly father loves his children. To appreciate what I am up to here, I do want to point out a few very important ideas. First, it may well be that the Christian believer has immediate cognitive defeating mechanisms, such as a thoroughly considered past array of experiences whereby positive belief in God was maintained due to positive experiences in one’s life. However, as part of my analysis, I am breaking down the act of belief formation and the mechanisms important to such formation of beliefs into some of the important component parts. But by so distinguishing between the belief mechanisms, I am not meaning to imply (and probably would rather want to deny) that many of the belief-forming mechanisms that we enjoy definitely do not work simultaneously to produce their intended effects.
Second, let me add that this model I’m presenting is also consistent with the person who is so certain of God’s existence and goodness that he/she does not doubt at all, even in the midst of exasperating evil. While I have perhaps never met someone who would fall into this category of human persons who are able not to doubt (posse not dubitare?), still such is possible. In such an instance, we could say that the person is either so resolute and assured of God’s goodness that D-beliefs never come to his mind; or, never come consciously, on that occasion, to his mind; or, his mind simply lacks some part of the design plan which usually functions so that D-beliefs are formed in those circumstances. I do not mean to build in auxiliary hypothesis into my model here that causes it to be unverifiable and resilient to testing. But the experience of the formation of D-beliefs is so well verified in common experience (and in the literature of the world) in common day to day life that such exceptions would seem exceptionally rare. Even Jesus praying in the garden before his arrest is akin to this idea of forming D-beliefs, in a natural way, when he experiences the pangs of exasperating evil.
Forming a belief of doubt, or “D-Belief,” then, is part of the natural process of soul-maturation, and, importantly, is not essentially sinful. It is important to note, in the general context of the soul-making theodicy, that this point is consistent, I believe, with that theodical approach as well as with the traditional account of Adam’s original created state. Recent versions of virtue ethics work well in this proposed model, and, when applied to Adam, see Adam as one who was not created as absolutely morally perfect, but rather morally spotless and in process of undergoing moral growth toward moral perfection. He was so disposed that he was able not to sin, being able to grow incrementally by responding to progressively revealed commands and moral situations by God. Adam would not be considered as created absolutely morally perfect, for moral perfection has significant moral experience through which one has lived as a necessary condition, which is not the case for Adam according to traditional Genesis account. However, Adam failed in one of the steps that was revealed to him as a commandment of God to be resolutely followed, as recorded in the Book of Genesis, and this was sufficient to warrant the consequence that God had declared, namely, that his disobedience would spell death. Let us examine the phenomenon of evil as we experience it in day to day life. Is it morally blameworthy to form a belief such as, “I’m doubting whether God exists and cares about me and my pain?” While it may be morally permissible to form belief in the uncaring nature of God (which would entail the nonexistence of God, after all) when evil makes a situation almost unbearable, it is not morally permissible, one could hold, to maintain and harbor belief in the nonexistence of God due to evil. Remaining in doubt without making use of positive reasons for God’s goodness and existence would be to misuse the good aspects of one’s own existence, and to defeat the overall purpose of the natural formation of D-Beliefs. We know that God’s creative activity always tends to secure goods which otherwise would not have been present. Secondly, we accept as a moral principle that to will some end necessarily implies willing the means to that end. Thus, if God wills some good end by allowing us to form D-beliefs, we know he also wills some means to that end. It would not be surprising if those means were some sort of defeater to this ability of the mind to sustain D-beliefs. We also hold that God’s excellent beneficence is dead set, ceteris paribus, against any evil that does not bring about a greater good, or, is highly likely to bring about a greater good, at some time in the life of humans. Yet, we see that upon severe suffering, Christians as well as nontheists form the belief, “I’m doubting whether God exists because of this or that evil situation.” What, then, is the intended good, in God’s good design of the human belief forming mechanism, in programming humans naturally to form such beliefs?
The intention, the soul-making theodicist maintains, of D-Beliefs is manifold, but perhaps one of the most important reasons for the existence of D- or Doubt-beliefs would be that a person consciously comes to a decision, by experiencing harsh evils, that he cannot secure a truly happy life on his own steam. This is the first stage, at least, in what we commonly call conversion. To see that one cannot live this life on one’s own steam means to come to see, taste and acknowledge that one is not an island unto himself, but rather a dependent being whose existence is frail and evidently upheld by another. This “another” is an outside source who has been merciful enough not to destroy one for the sinful attitudes, thoughts, and actions he has committed or entertained, but also merciful enough not to allow the person to continue in the illusion that human happiness consists in a life of seeking only one’s selfish human projects and ends.
There are, however, some “second-level” rational considerations that theodicists in general would do well to keep on the theodical playing field. In going back to Kant’s transcendental approach, if we know certain things to be likely true or eminently rational (where “rational” means being consistent with the belief that a properly functioning mind aimed at truth would form), we can ask “what are the conditions for the possibility of the truth or rationality of these things?”
To begin to develop this second-order, reflective stage, we can say the following. Each human person, in order to transcend the evil that besets him, must seek succor in one who is sufficiently strong to deliver him from the present evil and pain. In short, one is lead by experiencing tragedy to a relationship with the living God who desires to deliver us from these circumstances. One finds through the experience of almost insurmountable evils what one is really made out of, that this life in the flesh is fleeting and transient, and that certain decisions (about morality and spirituality) in this life are indeed the decisions that demand our deepest and most resolute attention.
This second stage, whereby we can come to warranted conclusions about evil, God, and existence, might be described as a belief-stage whereby we go behind what John Rawls has called the “veil of ignorance.” Imagine a situation in which you, as a benevolent rational spectator, consider characteristics of the world to be created, without knowing exactly what your existence in that world would be. Here we come to believe that God must have a certain nature if he created us as beings who on the one hand share many of the attributes that we naturally attribute to Deity or Godhood (rationality, self-consciousness, language, types of reasoning, mathematic ability, etc.), and yet suffer greatly in this life.
The Gestalt experiment I bring up here using Rawls’ veil of ignorance is a rational inquiry into the type of world a God who is all-good and all-powerful and all-knowing would make. Figuring that the following four possibilities are presented to a benevolent inhabitant-to-be in the world to be selected, what world would you choose to be the case?
1. A world in which no one suffers;
2. A world in which humankind suffers but God does not suffer.
3. A world in which humankind does not suffer but God does suffer.
4. A world in which both humankind suffers and God suffers.
I dare say that our sense of justice would preclude the mind behind the veil of ignorance to choose either 2 or 3. Therefore, there remains for consideration option 1 or 4. If we are committed to the view of Romans 5, that suffering is a necessary, in fact, logically necessary, condition for obtaining a good character which in turn is necessary for securing hope (that is, assurance of future beneficial experiences for the conscious mind), then it seems we are lead to elect option #4 over option #1.
Secondly, we can see that evil and suffering do not just occasionally act as extrinsic goods for human agents, but are in fact logically necessary for the attainment of certain great goods. For example, if God desires Ralph to acquire the property “bearing pain courageously,” it is logically necessary for Ralph to experience pain to possibly gain this property. To acquire virtues, according to Christian and Aristotelian ethics, one must persevere through a danger (to acquire the habit of courage), or live through significant pressure (to acquire the habit of fortitude), or overcome temptations (to acquire self-control), etc. In short: to acquire virtues, one must acquire good habits through encountering significant evils. A virtuous character is one who can, in time, help to turn an intrinsic evil into (or largely into) an extrinsic good. In the Christian view of things, the virtuous character, who has “love” as a binding agent over all that it does (cf. Col 3:14), is able to help turn “suffering,” with God’s grace, into perseverance, giving rise to Christian habits of long-suffering, self-control, and the like, which in turn produce hope of gaining a truly happy life.
We have held, then, that forming D-beliefs in God is not essentially sinful. What, though, of maintaining D-beliefs? Here, the theodicist may posit the existence of another type of, as it were, “defense mechanism” in the human belief forming mechanism which, it is being held, is a function that is created by God. The defense mechanism is the forming of M-beliefs and meta-M beliefs. M-beliefs, or memory beliefs, are formed and often retained when a human experiences life in all of its convolutions, twists and turns, as well as in everyday life and living. Meta-M beliefs are warranted beliefs that are formed, synthesized, on the basis of M-beliefs. Meta-M theistic beliefs are the beliefs that show the positive cumulative weight of reasons for belief and trust in God (cf. Romans 1:18ff).
Meta-M beliefs are the natural defense mechanisms against D-beliefs. For is it not true that what gets the Christian believer through doubts and valleys are the certitudes of seeing glimpses of God’s face, of the mountaintop experiences of seeing God’s healing and miraculous hand at work in one’s life? Is it not a miracle that sinful human individuals are brought to actually see their vileness, to confess it, and to put their trust in Christ Jesus for the forgiveness of their sins? Is there not a whole array of intellectual reasons, testimony, and other evidences whose cumulative effect is the conclusion that there is an eternal God who cares for us and holds us within his careful watch? We conclude that Meta-M beliefs are God’s built-in defense mechanism in humans to defeat D-beliefs. We simply must remember that God, who is awesome, made us many promises that fly in the face of the present evil, promises that say, “if you bear the pains of this life, and believe in me and my promises, you will enter into my rest.” The same Psalmist who cried “How long, O Lord?” completes the psalm by saying these words significant in this context:
Look on me and answer, O Lord my God. Give light to my eyes, or I will sleep in death. My enemy will say: “I have overcome him, and my foes will rejoice when I fall. But I trust in your unfailing love; my heart rejoices in your salvation. I will sing to the Lord, for he has been good to me. [M-beliefs here overcome the D-beliefs] (Ps 13:3-6 [NIV])
But consider also the situation of the nonbeliever. It must be maintained that it is not morally and intellectually justifiable to maintain and harbor a D-belief. Does the nonbeliever have sufficient resources of data by which to construct coherent Meta-M beliefs that are sufficient to defeat the invasive doubt beliefs whose implication is that God does not exist?
There are many other significant rational considerations, besides what going “behind the veil” has told us, about God and evil. I note just four below:
1. A caring, saving God would appear only once in history to save humankind as we know it (he would not make no appearance, because He cares; not more than once, because two or more epiphanies would cause equal numbers of claims of superior and authoritative revelations of God).
2. If God revealed Himself, there would be a textual aspect to that revelation (because that is the most effective way in this world to preserve thoughts the longest without corruption by opinion and false report).
3. God would not necessarily eradicate evil at that exact point when it got to be too much to bear for any single human individual (for we would inductively learn this, and transfer all “bearing” of pain to God immediately upon suffering, which would defeat the end of soul-making).
4. God and humans would be called upon in this life to bear pain commensurate with their metaphysical stature (this concerns the amount of evil born and the effect of humans and God bearing evils).
The Rawlsian thought experience told us that God, if He exists (the unbeliever might reason), would likely create a world in which both man and God suffer. What this means, when added to point four (4), above, is that God would bear an amount of pain and suffering in this world commensurate with the pain and suffering of any human individual. We know that the passion week of Christ, the time of the active and passive humility of Christ, meant for Jesus a most excruciating amount of pain and suffering. I have heard of only a few stories of torture and difficulty that begin to approach the agonies of Calvary and the Passion Week that our Lord bore in His body on the Cross. I am not saying here that by using this Rawlsian thought experiment, the sufferings of Christ suddenly become clear for the unbeliever. Clearly they do not. Rather, I am saying that there are significant rational tools by which we can get the unbeliever to acknowledge that his sense of justice completely agrees with the Christian story, this story that a good theodicy will no doubt tell and bring to light, in a way consistent with the conclusions that the unbeliever can come to acknowledge using the “steam” of his reason alone.
Thus, evil shows itself to be an important extrinsic good in a moral universe in which we (both theists and atheists) are commanded (by our conscience) to overcome the naturally-formed D-Belief by using another naturally-formed set of beliefs: M-Beliefs (memory beliefs), and the structure of a good “life worth living” seen in one’s existence formed by the recombination of those M-Beliefs.
One epistemological criticism is obvious, and demands an answer. Could not the atheist simply respond, “I could just as well say that D-beliefs are the ‘natural defense mechanism’ against wishful thinking such as are expressed in ‘Meta-M theological beliefs.’ Therefore, we are at a draw and neither side wins. If anything, the evils of this world defeat the idea that God exists, because the evidence for God’s existence dwindles in the shadow of the concentration camps of WWII alone.” However, the epistemological consideration saves the day for the theist. For he holds that it is precisely in the fact that the mind exhibits intelligent design that shows that D-beliefs are not the “correct” belief, but rather are corrected by remembering God who created the mind to defeat such beliefs by the memory of His mercy and grace in our lives.
Let us tie together some conclusions from our short study. The context of our inquiry is the soul-making theodicy. Paul says that hope is made possible by suffering. Aristotle concurs that suffering is essential for character development. Character and hope development are important ends for the Christian.
As each episode of exasperating evil occurs of which we become aware, there is a mechanism by which humans form the rational belief that can defeat or undercut or override the D-belief mechanism from forming and harboring a belief in the nonexistence of God.
Reason gives some insights that can be useful in a theodicy to get the unbeliever to form the belief that he cannot obtain a lasting happy life on his own steam. The result of our Rawlsian thought experiment was the belief that God would favor those worlds in which both God and humans suffer evil. A further belief, possibly formed here, would be that God and humans in this envisaged world would suffer to an extent commensurate with one’s own internal metaphysical stature.
The results for the soul-making theodicist from our study are two-fold. First, evil is shown to be an extrinsic good, because when God wills that we ought to morally mature, he simultaneous also wills the means to that end. The means to come to acquire the property of “courageously bearing pain” is clearly the human bearing pain of some sort as a logically necessary condition. Secondly, we form D-beliefs in the face of evil, which shows, in effect, that we are concerned with human being (because one person is caring for another, etc.). But this clearly shows that we value persons, meaning that, again, we necessarily will the means to the end of building the character (“souls”) of people. But if this is so, it acts as a powerful reason to show that we will that evil should exist, since it is a necessary condition for the building of persons. We cannot ultimately complain, therefore, about evils, since they are necessary conditions for the maturity of persons.
We believe God has a good reason for the evils that He allows. When we become exasperated with evil, we form D-beliefs, which are not sinful to form, but natural and in line with our design plan. But God’s past goodnesses to his human creatures, of which it is reasonable to believe any sound rational human mind would be sufficiently aware, warrant the formation of Meta-M beliefs that defeat or override harboring D-beliefs. That is, past goods overcome present evils, and cause us to hope, if we persevere, to enjoy the promise of a happy future existence.
Perhaps if I have contributed anything to the continuing debate on theodicy here it is to give some reasons (besides attributing it to immaturity) that even a seasoned Christian will form D-beliefs about God’s goodness when evil strikes in his life. God deserves all of our worship, and desires to give us a true, lasting happiness. To get us to worship Him properly and to accept His gracious gift of happiness freely, He allows enough pain and suffering so that we form a habit and virtue of faith from the constancy of experience. God uses evil as a logically necessary willed means to the end of soul-making, to bring us to be more and more into the image of Christ and to make us fit vessels for eternal fellowship with Him. The first logical step on the road to Christ-likeness, I have maintained, is for a person to form the belief “I cannot secure a lasting happiness on my own steam.” God is too merciful to allow us to continue in the illusion that we can solve all of our own problems. But He calls us to be builders. And we will build the habit and virtue of love as we keep the Lord’s commands, and we will build the habit and virtue of hope as we persevere doing what is right and good, in spite of the ever-present reality and awfulness of evil.*
 Alvin Plantinga, Warrant and Proper Function (Oxford, 1993).
 In The Christian Theology Reader, ed. Alister E. McGrath (Blackwell, 1995), p. 6.
 C.S. Lewis, The Last Battle (Collier Books, 1956), p. 170.
 St. Augustine, Confessions, trans.R.S. Pine-Coffin (Penguin, 1961), p. 21.
 I think especially here of Linda Zagzebski and Keith Yandell in this context. See, for example, Yandell’s “Tragedy and Evil,” in International Journal for Philosophy of Religion 26 (1994), pp. 1-26.
 John Rawls, A Theory of Justice (Harvard, 1973).
 In this context, it is no surprise to the rational mind, I am claiming, to understand or accept that God would have “a chosen people” to whom He intimately revealed Himself as creator, savior, providence and judge.
 You could of course say that the human could just seem to be in pain. But, seeming to be in pain and being in pain are indistinguishable and therefore functionally equivalent in human experience. Also, God would not be a deceiver on such a vast scale in a world, so that almost universally our belief-forming mechanisms would tell us that we were experiencing pain daily, when in actuality there was no pain in that world.
*I thank John Warwick Montgomery and Melanie Martin for their comments on an earlier draft of this paper.