Professor Peter Kreeft and a colleague have written a book entitled Twenty Arguments for the Existence of God. These are summarized on the website http://www.peterkreeft.com/topics-more/20_arguments-gods-existence.htm .
Below, you will find the initial summaries of the discussion on these
20 arguments. We have included only the first five. You are encouraged
to read the rest at the website in order to familiarize yourself with
these arguments. As Dr. Clouser says, however, they are not fully convincing and are not needed for belief in God to be intellectually warranted. -- Bob Zomermaand
Twenty Arguments God's Existence
- The Argument from Change
- The Argument from Efficient Causality
- The Argument from Time and Contingency
- The Argument from Degrees of Perfection
- The Design Argument
- The Kalam Argument
- The Argument from Contingency
- The Argument from the World as an Interacting Whole
- The Argument from Miracles
- The Argument from Consciousness
- The Argument from Truth
- The Argument from the Origin of the Idea of God
- The Ontological Argument
- The Moral Argument
- The Argument from Conscience
- The Argument from Desire
- The Argument from Aesthetic Experience
- The Argument from Religious Experience
- The Common Consent Argument
- Pascal's Wager
In this section you will find arguments of many different kinds for the existence of God. And we make to you, the reader, an initial appeal. We realize that many people, both believers and nonbelievers, doubt that God's existence can be demonstrated or even argued about. You may be one of them. You may in fact have a fairly settled view that it cannot be argued about. But no one can reasonably doubt that attention to these arguments has its place in any book on apologetics. For very many have believed that such arguments are possible, and that some of them actually work.
They have also believed that an effective rational argument for God's existence is an important first step in opening the mind to the possibility of faith—in clearing some of the roadblocks and rubble that prevent people from taking the idea of divine revelation seriously. And in this they have a real point. Suppose our best and most honest reflection on the nature of things led us to see the material universe as self-sufficient and uncaused; to see its form as the result of random motions, devoid of any plan or purpose. Would you then be impressed by reading in an ancient book that there exists a God of love, or that the heavens proclaim his glory? Would you be disposed to take that message seriously? More likely you would excuse yourself from taking seriously anything claimed as a communication from the Creator. As one person put it: I cannot believe that we are children of God, because I cannot believe there is anyone to do the adopting.
It is this sort of cramped and constricted horizon that the proofs presented in this chapter are trying to expand. They are attempts to confront us with the radical insufficiency of what is finite and limited, and to open minds to a level of being beyond it. If they succeed in this—and we can say from experience that some of the proofs do succeed with many people—they can be of very great value indeed.
You may not feel that they are particularly valuable to you. You may be blessed with a vivid sense of God's presence; and that is something for which to be profoundly grateful. But that does not mean you have no obligation to ponder these arguments. For many have not been blessed in that way. And the proofs are designed for them—or some of them at least—to give a kind of help they really need. You may even be asked to provide help.
Besides, are any of us really in so little need of such help as we may claim? Surely in most of us there is something of the skeptic. There is a part of us tempted to believe that nothing is ultimately real beyond what we can see and touch; a part looking for some reason, beyond the assurances of Scripture, to believe that there is more. We have no desire to make exaggerated claims for these demonstrations, or to confuse "good reason" "with scientific proof." But we believe that there are many who want and need the kind of help these proofs offer more than they might at first be willing to admit.
A word about the organization of the arguments. We have organized them into two basic groups: those which take their data from without—cosmological arguments—and those that take it from within—psychological arguments. The group of cosmological arguments begins with our versions of Aquinas's famous "five ways." These are not the simplest of the arguments, and therefore are not the most convincing to many people. Our order is not from the most to the least effective. The first argument, in particular, is quite abstract and difficult.
Not all the arguments are equally demonstrative. One (Pascal's Wager) is not an argument for God at all, but an argument for faith in God as a "wager." Another (the ontological argument) we regard as fundamentally flawed; yet we include it because it is very famous and influential, and may yet be saved by new formulations of it. Others (the argument from miracles, the argument from religious experience and the common consent argument) claim only strong probability, not demonstrative certainty. We have included them because they form a strong part of a cumulative case. We believe that only some of these arguments, taken individually and separately, demonstrate the existence of a being that has some of the properties only God can have (no argument proves all the divine attributes); but all twenty taken together, like twined rope, make a very strong case.
The material world we know is a world of change. This young woman came to be 5'2", but she was not always that height. The great oak tree before us grew from the tiniest acorn. Now when something comes to be in a certain state, such as mature size, that state cannot bring itself into being. For until it comes to be, it does not exist, and if it does not yet exist, it cannot cause anything.
As for the thing that changes, although it can be what it will become, it is not yet what it will become. It actually exists right now in this state (an acorn); it will actually exist in that state (large oak tree). But it is not actually in that state now. It only has the potentiality for that state.
Now a question: To explain the change, can we consider the changing thing alone, or must other things also be involved? Obviously, other things must be involved. Nothing can give itself what it does not have, and the changing thing cannot have now, already, what it will come to have then. The result of change cannot actually exist before the change. The changing thing begins with only the potential to change, but it needs to be acted on by other things outside if that potential is to be made actual. Otherwise it cannot change.
Nothing changes itself. Apparently self-moving things, like animal bodies, are moved by desire or will—something other than mere molecules. And when the animal or human dies, the molecules remain, but the body no longer moves because the desire or will is no longer present to move it.
Now a further question: Are the other things outside the changing thing also changing? Are its movers also moving? If so, all of them stand in need right now of being acted on by other things, or else they cannot change. No matter how many things there are in the series, each one needs something outside itself to actualize its potentiality for change.
The universe is the sum total of all these moving things, however many there are. The whole universe is in the process of change. But we have already seen that change in any being requires an outside force to actualize it. Therefore, there is some force outside (in addition to) the universe, some real being transcendent to the universe. This is one of the things meant by "God."
Briefly, if there is nothing outside the material universe, then there is nothing that can cause the universe to change. But it does change. Therefore there must be something in addition to the material universe. But the universe is the sum total of all matter, space and time. These three things depend on each other. Therefore this being outside the universe is outside matter, space and time. It is not a changing thing; it is the unchanging Source of change.
We notice that some things cause other things to be (to begin to be, to continue to be, or both). For example, a man playing the piano is causing the music that we hear. If he stops, so does the music.
Now ask yourself: Are all things caused to exist by other things right now? Suppose they are. That is, suppose there is no Uncaused Being, no God. Then nothing could exist right now. For remember, on the no-God hypothesis, all things need a present cause outside of themselves in order to exist. So right now, all things, including all those things which are causing things to be, need a cause. They can give being only so long as they are given being. Everything that exists, therefore, on this hypothesis, stands in need of being caused to exist.
But caused by what? Beyond everything that is, there can only be nothing. But that is absurd: all of reality dependent—but dependent on nothing! The hypothesis that all being is caused, that there is no Uncaused Being, is absurd. So there must be something uncaused, something on which all things that need an efficient cause of being are dependent.
Existence is like a gift given from cause to effect. If there is no one who has the gift, the gift cannot be passed down the chain of receivers, however long or short the chain may be. If everyone has to borrow a certain book, but no one actually has it, then no one will ever get it. If there is no God who has existence by his own eternal nature, then the gift of existence cannot be passed down the chain of creatures and we can never get it. But we do get it; we exist. Therefore there must exist a God: an Uncaused Being who does not have to receive existence like us—and like every other link in the chain of receivers.
Question 1: Why do we need an uncaused cause? Why could there not simply be an endless series of things mutually keeping each other in being?
Reply: This is an attractive hypothesis. Think of a single drunk. He could probably not stand up alone. But a group of drunks, all of them mutually supporting each other, might stand. They might even make their way along the street. But notice: Given so many drunks, and given the steady ground beneath them, we can understand how their stumblings might cancel each other out, and how the group of them could remain (relatively) upright. We could not understand their remaining upright if the ground did not support them—if, for example, they were all suspended several feet above it. And of course, if there were no actual drunks, there would be nothing to understand.
This brings us to our argument. Things have got to exist in order to be mutually dependent; they cannot depend upon each other for their entire being, for then they would have to be, simultaneously, cause and effect of each other. A causes B, B causes C, and C causes A. That is absurd. The argument is trying to show why a world of caused causes can be given—or can be there—at all. And it simply points out: If this thing can exist only because something else is giving it existence, then there must exist something whose being is not a gift. Otherwise everything would need at the same time to be given being, but nothing (in addition to "everything") could exist to give it. And that means nothing would actually be.
Question 2: Why not have an endless series of caused causes stretching backward into the past? Then everything would be made actual and would actually be—even though their causes might no longer exist.
Reply: First, if the kalam argument (argument 6) is right, there could not exist an endless series of causes stretching backward into the past. But suppose that such a series could exist. The argument is not concerned about the past, and would work whether the past is finite or infinite. It is concerned with what exists right now.
Even as you read this, you are dependent on other things; you could not, right now, exist without them. Suppose there are seven such things. If these seven things did not exist, neither would you. Now suppose that all seven of them depend for their existence right now on still other things. Without these, the seven you now depend on would not exist—and neither would you. Imagine that the entire universe consists of you and the seven sustaining you. If there is nothing besides that universe of changing, dependent things, then the universe—and you as part of it—could not be. For everything that is would right now need to be given being but there would be nothing capable of giving it. And yet you are and it is. So there must in that case exist something besides the universe of dependent things—something not dependent as they are.
And if it must exist in that case, it must exist in this one. In our world there are surely more than seven things that need, right now, to be given being. But that need is not diminished by there being more than seven. As we imagine more and more of them—even an infinite number, if that were possible—we are simply expanding the set of beings that stand in need. And this need—for being, for existence—cannot be met from within the imagined set. But obviously it has been met, since contingent beings exist. Therefore there is a source of being on which our material universe right now depends.
- We notice around us things that come into being and go out of being. A tree, for example, grows from a tiny shoot, flowers brilliantly, then withers and dies.
- Whatever comes into being or goes out of being does not have to be; nonbeing is a real possibility.
- Suppose that nothing has to be; that is, that nonbeing is a real possibility for everything.
- Then right now nothing would exist. For
- If the universe began to exist, then all being must trace its origin to some past moment before which there existed—literally—nothing at all. But
- From nothing nothing comes. So
- The universe could not have begun.
- But suppose the universe never began. Then, for the infinitely long duration of cosmic history, all being had the built-in possibility not to be. But
- If in an infinite time that possibility was never realized, then it could not have been a real possibility at all. So
- There must exist something which has to exist, which cannot not exist. This sort of being is called necessary.
- Either this necessity belongs to the thing in itself or it is derived from another. If derived from another there must ultimately exist a being whose necessity is not derived, that is, an absolutely necessary being.
- This absolutely necessary being is God.
Question1: Even though you may never in fact step outside your house all day, it was possible for you to do so. Why is it impossible that the universe still happens to exist, even though it was possible for it to go out of existence?
Reply: The two cases are not really parallel. To step outside your house on a given day is something that you may or may not choose to do. But if nonbeing is a real possibility for you, then you are the kind of being that cannot last forever. In other words, the possibility of nonbeing must be built-in, "programmed," part of your very constitution, a necessary property. And if all being is like that, then how could anything still exist after the passage of an infinite time? For an infinite time is every bit as long as forever. So being must have what it takes to last forever, that is, to stay in existence for an infinite time. Therefore there must exist within the realm of being something that does not tend to go out of existence. And this sort of being, as Aquinas says, is called "necessary."
We notice around us things that vary in certain ways. A shade of color, for example, can be lighter or darker than another, a freshly baked apple pie is hotter than one taken out of the oven hours before; the life of a person who gives and receives love is better than the life of one who does not.
So we arrange some things in terms of more and less. And when we do, we naturally think of them on a scale approaching most and least. For example, we think of the lighter as approaching the brightness of pure white, and the darker as approaching the opacity of pitch black. This means that we think of them at various "distances" from the extremes, and as possessing, in degrees of "more" or "less," what the extremes possess in full measure.
Sometimes it is the literal distance from an extreme that makes all the difference between "more" and "less." For example, things are more or less hot when they are more or less distant from a source of heat. The source communicates to those things the quality of heat they possess in greater or lesser measure. This means that the degree of heat they possess is caused by a source outside of them.
Now when we think of the goodness of things, part of what we mean relates to what they are simply as beings. We believe, for example, that a relatively stable and permanent way of being is better than one that is fleeting and precarious. Why? Because we apprehend at a deep (but not always conscious) level that being is the source and condition of all value; finally and ultimately, being is better than nonbeing. And so we recognize the inherent superiority of all those ways of being that expand possibilities, free us from the constricting confines of matter, and allow us to share in, enrich and be enriched by, the being of other things. In other words, we all recognize that intelligent being is better than unintelligent being; that a being able to give and receive love is better than one that cannot; that our way of being is better, richer and fuller than that of a stone, a flower, an earthworm, an ant, or even a baby seal.
But if these degrees of perfection pertain to being and being is caused in finite creatures, then there must exist a "best," a source and real standard of all the perfections that we recognize belong to us as beings.
This absolutely perfect being—the "Being of all beings," "the Perfection of all perfections"—is God.
Question 1: The argument assumes a real "better." But aren't all our judgments of comparative value merely subjective?
Reply: The very asking of this question answers it. For the questioner would not have asked it unless he or she thought it really better to do so than not, and really better to find the true answer than not. You can speak subjectivism but you cannot live it.
This sort of argument is of wide and perennial appeal. Almost everyone admits that reflection on the order and beauty of nature touches something very deep within us. But are the order and beauty the product of intelligent design and conscious purpose? For theists the answer is yes. Arguments for design are attempts to vindicate this answer, to show why it is the most reasonable one to give. They have been formulated in ways as richly varied as the experience in which they are rooted. The following displays the core or central insight.
- The universe displays a staggering amount of intelligibility, both within the things we observe and in the way these things relate to others outside themselves. That is to say: the way they exist and coexist display an intricately beautiful order and regularity that can fill even the most casual observer with wonder. It is the norm in nature for many different beings to work together to produce the same valuable end—for example, the organs in the body work for our life and health. (See also argument 8.)
- Either this intelligible order is the product of chance or of intelligent design.
- Not chance.
- Therefore the universe is the product of intelligent design.
- Design comes only from a mind, a designer.
- Therefore the universe is the product of an intelligent Designer.
The first premise is certainly true-even those resistant to the argument admit it. The person who did not would have to be almost pathetically obtuse. A single protein molecule is a thing of immensely impressive order; much more so a single cell; and incredibly much more so an organ like the eye, where ordered parts of enormous and delicate complexity work together with countless others to achieve a single certain end. Even chemical elements are ordered to combine with other elements in certain ways and under certain conditions. Apparent disorder is a problem precisely because of the overwhelming pervasiveness of order and regularity. So the first premise stands.
If all this order is not in some way the product of intelligent design—then what? Obviously, it "just happened." Things just fell out that way "by chance." Alternatively, if all this order is not the product of blind, purposeless forces, then it has resulted from some kind of purpose. That purpose can only be intelligent design. So the second premise stands.
It is of course the third premise that is crucial. Ultimately, nonbelievers tell us, it is indeed by chance and not by any design that the universe of our experience exists the way it does. It just happens to have this order, and the burden of proof is on believers to demonstrate why this could not be so by chance alone.
But this seems a bit backward. It is surely up to nonbelievers to produce a credible alternative to design. And "chance" is simply not credible. For we can understand chance only against a background of order. To say that something happened "by chance" is to say that it did not turn out as we would have expected, or that it did turn out in a way we would not have expected. But expectation is impossible without order. If you take away order and speak of chance alone as a kind of ultimate source, you have taken away the only background that allows us to speak meaningfully of chance at all. Instead of thinking of chance against a background of order, we are invited to think of order-overwhelmingly intricate and ubiquitous order-against a random and purposeless background of chance. Frankly, that is incredible. Therefore it is eminently reasonable to affirm the third premise, not chance, and therefore to affirm the conclusion, that this universe is the product of intelligent design.
Question 1: Hasn't the Darwinian theory of evolution shown us how it is possible for all the order in the universe to have arisen by chance?
Reply: Not at all. If the Darwinian theory has shown anything, it has shown, in a general way, how species may have descended from others through random mutation; and how survival of these species can be accounted for by natural selection—by the fitness of some species to survive in their environment. In no way does it—can it—account for the ubiquitous order and intelligibility of nature. Rather, it presupposes order. To quote a famous phrase: "The survival of the fittest presupposes the arrival of the fit." If Darwinians wish to extrapolate from their purely biological theory and maintain that all the vast order around us is the result of random changes, then they are saying something which no empirical evidence could ever confirm; which no empirical science could ever demonstrate; and which, on the face of it, is simply beyond belief.
Question 2: Maybe it is only in this region of the universe that order is to be found. Maybe there are other parts unknown to us that are completely chaotic—or maybe the universe will one day in the future become chaotic. What becomes of the argument then?
Reply: Believers and nonbelievers both experience the same universe. It is this which is either designed or not. And this world of our common experience is a world of pervasive order and intelligibility. That fact must be faced. Before we speculate about what will be in the future or what may be elsewhere in the present, we need to deal honestly with what is. We need to recognize in an unflinching way the extent—the overwhelming extent—of order and intelligibility. Then we can ask ourselves: Is it credible to suppose that we inhabit a small island of order surrounded by a vast sea of chaos—a sea which threatens one day to engulf us?
Just consider how in the last decades we have strained fantastically at the limits of our knowledge; we have cast our vision far beyond this planet and far within the elements that make it up. And what has this expansion of our horizons revealed? Always the same thing: more—and not less—intelligibility; more—and not less—complex and intricate order. Not only is there no reason to believe in a surrounding chaos, there is every reason not to. It flies in the face of the experience that all of us—believers and nonbelievers—share in common.
Something similar can be said about the future. We know the way things in the universe have behaved and are behaving. And so, until we have some reason to think otherwise, there is every reason to believe it will continue on its orderly path of running down. No speculation can nullify what we know.
And, anyway, exactly what sort of chaos is this question asking us to imagine? That effect precedes cause? That the law of contradiction does not hold? That there need not be what it takes for some existing thing to exist? These suggestions are completely unintelligible; if we think about them at all, it is only to reject them as impossible. Can we imagine less order? Yes. Some rearrangement of the order we experience? Yes. But total disorder and chaos? That can never be considered as a real possibility. To speculate about it as if it were is really a waste of time.
Question 3: But what if the order we experience is merely a product of our minds? Even though we cannot think utter chaos and disorder, maybe that is how reality really is.
Reply: Our minds are the only means by which we can know reality. We have no other access. If we agree that something cannot exist in thought, we cannot go ahead and say that it might nevertheless exist in reality. Because then we would be thinking what we claim cannot be thought.
Suppose you claim that order is just a product of our minds. This puts you in a very awkward position. You are saying that we must think about reality in terms of order and intelligibility, but things may not exist that way in fact. Now to propose something for consideration is to think about it. And so you are saying: (a) we must think about reality in a certain way, but (b) since we think that things may not in fact exist that way, then (c) we need not think about reality the way we must think about it! Are we willing to pay that high a price to deny that the being of the universe displays intelligent design? It does not, on the face of it, seem cost effective.