Humanists embrace atheism or at least agnosticism. Some believe that belief in a god or gods is not particularly rational or justified. Others go further, insisting that belief in God is actually downright irrational.
Those who believe in God, on the other hand, while maintaining their belief is a “faith position”, nevertheless typically suppose their belief is not unreasonable. Believing in God, they suppose, is not, say, like believing in Santa or in fairies - it is much more reasonable than that. Perhaps God’s existence cannot be conclusively “proved”. But that God exists is, they think, at least a fairly reasonable thing for a modern, educated adult to believe.
But if belief in God is far more reasonable than, say, belief in fairies, what makes it more reasonable? Theists respond to this question in a variety of ways. Some attempt to offer some sort of rational argument for the existence of God.
There are many such arguments for the existence of God. It is of course impossible to do justice to all these arguments in the short space available here. Instead, I will provide illustrations of the two of the most popular kinds of argument for God’s existence, and indicate where humanist critics believe those arguments fall down. I begin with an example of a cosmological argument, and will then move on to arguments from design, including two contemporary versions based, respectively, on irreducible complexity and fine-tuning.
My aim is to provide a brief overview of the some of the problems and objections such arguments typically face.
The cosmological argument: Why is there anything at all?
Most of us have at some time or other looked up at the starry heavens and been struck by the thought – “Where did all this come from? Why is there something, rather than nothing?” This is a profound question – a question worthy of serious contemplation.
Scientists have, of course, developed theories about how the universe began. Currently, most scientists believe the universe began roughly 13.5 billion years ago with the Big Bang – an event with which not just matter and energy, but time and space, began.
However, such scientific answers appear merely to postpone the mystery rather than solve it. For of course we now want to know – but why was there a Big Bang? Why was there - is there - anything at all?
We seem at this point to be faced with a question that, necessarily, science cannot answer. Science explains natural phenomena by pointing to other features of the natural world – such as the laws of nature. For example, ask a scientist why the water froze in the pipes last night, and they may point out that (i) it is a law of nature that water freezes below zero, and (ii) last night the temperature of the water in the pipes fell below zero. That would explain why the water froze. But what explains why there are any laws of nature in the first place? Indeed, what explains why there is a natural world at all?
It is at this point, of course, that God and religion are supposed to enter the picture. God, it is suggested, explains what science cannot – why there is anything at all. The existence of God provides the only, or at least the best available, explanation for the existence of the universe.
While many theists admit that this does not constitute a conclusive “proof” of God’s existence, many believe such “cosmological” arguments – arguments that infer the existence of God as the only, or at least best, explanation of why the universe exists – do at least lend their belief a good deal of rational support.
But what explains God’s existence?
One obvious difficulty with this particular answer to the question “Why is there something, rather than nothing?”, as it stands, is that by introducing God we appear to have introduced just another “something” the existence of which now has to explained. What explains God’s existence? We have, it seems, merely pushed the mystery back a step, rather than solved it.
A standard theistic response to this objection is to insist that, unlike the natural world, God is a necessary being – something that, by its nature, cannot but exist. So with God, the search for the ultimate explanation of why there is anything at all comes to a satisfying end – there is no need to look behind God for a further something accounting for his existence (and then a further something behind that something that accounts for its existence, and so on ad infinitum). With God, we reach the end of the line.
Other problems with the cosmological argument
The kind of cosmological argument sketched out above runs into several well-known difficulties. I shall outline just three.
First, the argument assumes that the question “Why is there something, rather than nothing?” actually makes sense. But does it? On closer examination, it is not so clear that it does. But then it does not require an answer. Here is one line of thought leading to the conclusion that the question is actually nonsensical.
Often, when we talk about there being “nothing”, we mean there exists, say, an empty bit of space. “When I say, “There’s nothing in my cup”, I mean that, right now, the space inside my cup is empty. And when I say, “I am doing nothing right now”, I mean that, at this moment in time, I am not doing anything. The spatio-temporal world supplies, as it were, the stage on which such examples of something or nothing might appear.
When we ask, “Why is there something, rather than nothing?” we are talking about a much more radical sort of nothing – what we might call absolute nothing. Not only is there no stuff and nothing going on, there’s no time or space in which any stuff could exist or anything could go on. The stage itself has now been removed.
This is a very profound and baffling sort of absence – so baffling it is not entirely clear the notion of absolute nothing even makes sense (it certainly raises some intriguing questions, such as “What is the difference between thinking about absolute nothing, and not thinking about anything?”).
It is tempting to say, “But of course the notion of absolute nothing makes sense. It’s just the notion of what there used to be, before anything existed.” But actually, absolute nothing is not what there used to be. There never was a time when there was absolutely nothing.
However, let’s concede, for the sake of argument, that the notion of absolute nothing does make sense, and that so does the question “Why is there something rather than nothing?” Our cosmological argument still faces other difficulties.
A second difficulty is this: the notion of necessary existence is by no means uncontroversial. Indeed, many philosophers have struggled, and failed, to make sense of the idea that anything could exist as a matter of necessity. One difficulty is that what is essential or necessary appears ultimately to be a product of our linguistic practices and ways of conceptualizing things.
For example, it is a necessary condition of something’s being a stallion that it be both male and a horse, because that is the definition of stallion. Being both male and a horse are, if you like, built into the concept of a stallion.
So if God, or something else, exists as a matter of necessity, then that would only be because God is defined or conceptualized that way, as something that exists. But of course, neither existence nor necessary existence can be conceptually guaranteed in this manner. If I define Woozle as the human who walked on the surface of the planet Mars in 2010, well then I know that if anyone is Woozle, then they walked on the Mars in 2010. But of course there is no such person as Woozle. No one has yet walked on Mars. And note that I certainly cannot guarantee such a person exist simply by adding existence to my definition like so: Woozle is the person who walked on the surface of Mars in 2010 and exists. Similarly, even if existence were included in the concept of God (and perhaps it is), that would not entail that any such being exists, let alone necessarily exists.
However, even if both these objections can be dealt with, there remain other formidable problems with our cosmological argument, including this: that even if the argument did succeed in establishing the existence of a necessary something-or-other behind the universe, it is, as it stands, a huge and unjustified further leap to the conclusion that this something-or-other is, say, something like a person, a person who listens to our prayers, who has moral properties such as supreme goodness, who performs miracles, and so on.
Our cosmological argument, as it stands, no more supports belief in, say, the Judeo-Christian God than it does belief a supremely powerful and morally ambivalent God, or indeed innumerable other gods and something-or-others. Which, of course, in each case, it barely supports, if at all.
Arguments from design
Let’s now turn to arguments from design (an unfortunate title as the claim that the universe was designed is a conclusion of these arguments, rather than their starting point – “arguments to design” would be better). These arguments begin with the observation that the natural world, or items within it, appears to have certain remarkable features – such as order and purpose. They conclude that, as God is the only, or at least the best available, explanation of those features, God exists.
Perhaps the best-known argument from design is that presented by William Paley in his Natural Theology, published in 1802. Paley argues that, were one to find a complex object such as a watch lying on the ground, it would be unreasonable to suppose that the watch came to exist by chance, or that it had always existed in that form. Given the clear purpose of the watch – to tell the time – and its highly complex construction geared to fulfilling that purpose, it is reasonable to suppose the watch was fashioned by an intelligent being for that purpose. But if that is a very reasonable conclusion to draw in the case of a watch, then surely it is no less reasonable to draw the same conclusion in the case of, say, the human eye, which also has a purpose for which it is exquisitely engineered. That intelligent designer, supposes Paley, is God.
That a biological organ such as the human eye must have some sort of designer was accepted by very many, including even the scientist Charles Darwin, up until Darwin developed his own alternative evolutionary account of how the eye appeared.
The mechanism Darwin realized could account for the gradual evolution of the eye is natural selection. When living organisms reproduce, their offspring may differ slightly in inheritable ways. Plant and animal breeders take advantage of these chance mutations to breed new strains. For example, a dog breeder might select from each generation of a dog those that are largest and least hairy, eventually producing a whole new breed of huge, bald dog.
Darwin’s great insight was to recognise that the natural environment in which organisms are located will, in effect, also select among offspring. Organisms with a chance mutation that enhances their ability to survive and reproduce in that environment will be more likely to pass that mutation on. Organisms with a mutation that reduces its chances of surviving and reproducing in that environment will be less likely to pass it on. And so, over a many generations organisms will gradually adapt to their environments. Indeed, under certain condition, a whole new species may emerge.
Darwin called this mechanism “natural selection”, contrasting it with the “artificial selection” used by dog and plant breeders. Unlike artificial selection, natural selection does not require an intelligent mind to guide the selection process towards a particular end. Selection is now taken care of entirely by blind, unthinking nature.
There is overwhelming fossil and other evidence both that the human eye did, indeed, evolve gradually over millions of years, beginning perhaps with the chance appearance of a single light sensitive cell in an organism living many millions of years ago, and that natural selection is the main mechanism that drove this evolutionary process. In fact, eyes provide such obvious survival value to organisms that they have evolved independently at least forty times.
The discovery of the mechanism of natural selection led Darwin to reject Paley’s argument from design. Darwin wrote:
The old argument of design in nature, as given by Paley, which formerly seemed to me so conclusive, fails, now that the law of natural selection has been discovered.
While the development of Darwin’s theory of natural selection, and, later, the theory of genetics (including the theory of genetic drift, another mechanism involved in driving the process of evolution), resulted in a decline in the popularity of arguments from design, such arguments have recently been making something of a come back. Two popular, more recent variants of the argument from design are outlined below.
The argument from irreducible complexity
Some, such as Professor of Biochemistry Michael Behe, author of Darwin’s Black Box, argue that there are certain features of biological organisms that Darwin’s theory of natural selection cannot explain. While Behe accepts that new species evolve and that natural selection plays a role in this, he maintains that some biological systems are irreducibly complex, and so cannot have evolved by natural selection.
By an irreducibly complex system Behe means
a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. P39
Behe uses the mousetrap to illustrate. Take any one part away – the base, the spring, the cheese, etc. – and the entire mechanism fails to function.
According to Behe,
an irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution. (p. 39).
It seems there are irreducibly complex systems in nature. Behe provides a number of illustrations, including a certain sort of bacterial flagellum – a whip-like appendage bacteria use to propel themselves. Each flagellum has at its base a kind of molecular motor drive comprising several parts each of which is essential if the flagellum is to work.
Why does Behe suppose that an irreducibly complex system such as this flagellum cannot evolve gradually by natural selection? Because, thinks Behe, there can be no reproductive or survival value to having only a part of the system. So it cannot evolve by stages. And the probability of the entire system spontaneously appearing in a single generation as a result of chance mutation is so low that it is far more reasonable to suppose some sort of intelligent designer lent a helping hand.
Behe’s argument for intelligent design is popular in certain religious circles. Some maintain that because the scientific community is currently divided on the question of whether some intelligence played a role in the emergence of life, the theory of intelligent design should be taught in schools alongside the theories of evolution and natural selection. This suggestion is designed to appeal to our sense of fairness – surely it is only fair that both sides in a scientific controversy should get a hearing?
The truth, however, is that the “scientific controversy” about intelligent design is a myth. There is no scientific controversy. Behe’s arguments have been entirely scientifically discredited.
In fact, plausible natural mechanisms by which all of Behe’s examples of irreducibly complex systems have been constructed. Some were known even before Behe published his book.
As Professor of biology Kenneth R. Miller points out, one of the ways in which natural selection can produce irreducibly complex systems is by combining elements that have previously evolved by natural selection for other functions. Just because part of the flagellum is useless for propelling the organism around does not mean that it is has non-functional. Indeed, we know that some of the components of the bacterial flagellum do have functions elsewhere:
[Behe] writes that in the absence of “almost any” of its parts, the bacterial flagellum “does not work.” But guess what? A small group of proteins from the flagellum does work without the rest of the machine — it’s used by many bacteria as a device for injecting poisons into other cells. Although the function performed by this small part when working alone is different, it nonetheless can be favored by natural selection. REF http://www.actionbioscience.org/evolution/nhmag.html
From Miller’s contribution to “Intelligent design?” Natural History magazine. April 2002.
In short, Behe’s key claim that having only part of an irreducibly complex mechanism can have no reproductive or survival value for the organism is simply wrong. If you suspect that Miller says this because he is an atheist, think again: Miller is religious. It is not, says Miller, anti-religious bias that explains why the scientific community reject Behe’s arguments:
In the final analysis, the biochemical hypothesis of intelligent design fails not because the scientific community is closed to it but rather for the most basic of reasons — because it is overwhelmingly contradicted by the scientific evidence. REF ibid
The physicist Lawrence Krauss writes…
The dishonesty of [intelligent design] lies in its proponents pointing to a controversy when there really is no controversy. A friend of mine did an informal survey of more than ten million articles in major science journals during the past twelve years. Searching for the key word evolution pulled up 115,000 articles, most pertaining to biological evolution. Searching for Intelligent Design yielded eighty-eight articles. All but eleven of those were in engineering journals, where, of course, we hope there is discussion of intelligent design! Of the eleven articles, eight were critical of the scientific basis for Intelligent Design theory and the remaining three turned out to be articles in conference proceedings, not peer-reviewed research journals. So that’s the extent of the "controversy" in the scientific literature. There is none.
To teach children that there is a scientific controversy about intelligent design would be to teach them a simple falsehood. The fact that schools have taught children this, whether or not in science class, is an educational disgrace.
The fine-tuning argument
Many leading scientists believe that our universe is, in a sense, “fine-tuned” for life. It has been suggested that for life to emerge in the universe, the laws of nature and initial conditions of the universe have to be just so. Had certain forces been slightly stronger or weaker, or certain dimensions or quantities values slightly smaller or larger, life either could not, or would have been very unlikely to, emerge. Here, for example, is Stephen Hawking:
The remarkable fact is that the values of these [fundamental] numbers seem to have been very finely adjusted to make possible the development of life. For example, if the electric charge of the electron had been only slightly different, stars either would have been unable to burn hydrogen and helium, or they would have exploded.
It is often said that the probability of the universe having such a combination of features just by chance is very small indeed. So small, in fact, that some believe it more reasonable to suppose that some sort of intelligent agent deliberately designed the universe this way. This intelligence, many will add, is God. God supplies a satisfying explanation for what would otherwise be an extraordinarily improbable set of coincidences. It is therefore reasonable to suppose that God exists.
To what extent do these and other observations of the natural world really support belief in God? Hardly, if at all.
To begin with, note that the claim that the universe is significantly fine-tuned is not entirely scientifically uncontroversial.
For example, some scientists believe there may well be a multiverse – a plethora of universes governed by a wide range of different physical laws. If there is a multiverse, then it’s not particularly unlikely that there should happen to exist a universe that has the Goldilocks property of being “just right” for life.
Even if there is only one universe, a number of scientists in any case question whether there is only a very narrow range of physical parameters within which life might plausibly emerge. Physicists including Victor Stenger, Anthony Aguire, and Craig Hogan have studied those universes that result when six cosmological parameters are simultaneously varied by several orders of magnitude, and have found that stars, planets and life are likely within many of them.
According to these physicists it is by no means scientifically obvious that there is only a very narrow set of physical parameters within which life might arise.
But still, let’s concede, for the sake of argument, that the science on which cosmic fine-tuning arguments are based has been established beyond reasonable doubt.
There are many more problems. A key idea on which fine-tuning arguments rely – that we can talk intelligibly about the universe and its basic features as being either “probable” or “improbable” – has also repeatedly been challenged by philosophers (including religious philosophers such as Tim and Lydia McGrew, who have no particular anti-religious axe to grind). REFERENCE
Still, let’s suppose, for the sake of argument, both that the universe is significantly fine-tuned for life, and also that it is highly improbable it should have such life-supporting features just by chance. To what extent would this fact support belief in the existence of some sort of transcendent, intelligent being who deliberately designed the universe that way?
Does the transcendent intelligence hypothesis even make sense?
A further objection to the fine-tuning argument – made by Richard Dawkins and others - is that by appealing to a cosmic intelligent designer, we are appealing to a being who must be at least as complex, and so at least as improbable, as the universe he is supposed to have designed. If the complexity of the universe should lead us to suppose it has a designer, shouldn’t the complexity of the designer lead us to suppose that designer had a designer, and so on ad infinitum?
But even if we also set this objection to one side, there remain other, perhaps deeper, difficulties. First of all, it is by no means obvious that the idea of a transcendent intelligent designer even makes sense.
Human beings explain features of the world around them in two main ways. One way is to supply naturalistic explanations that appeal to features of the natural world, such as natural events, forces and laws. The explanations of physics and chemistry fall into this category. The other way is to offer intentional explanations – explanations that appeal to the beliefs and desires or more or less rational agents. Why is there a tree in this spot? Because Ted wanted to see a tree from his bedroom window, and so planted a sapling here correctly supposing it would grow into a handsome tree.
When we are unable to explain something naturalistically, it is, of course, tempting to look for an intentional explanation instead. When we could not offer naturalistic explanations for why the heavenly bodies moved about as they did, we supposed that they must be, or must be moved by, agents - gods of some sort. When we could not otherwise explain diseases and natural disasters, we put them down to the actions of malevolent agents, such as witches and demons. When we could not provide naturalistic explanations for the growth of plants and the cycle of the seasons, we again invoked agents – sprites, fairies, and gods or various sorts.
As our scientific understanding of the world has increased, so the need to invoke witches, fairies, demons and other such agents to account for features of the natural world around us has diminished. However, when we ask: why does the natural world exist at all, and what explains why it has the fundamental laws does? such naturalistic explanations are unavailable. So an explanation in terms of the activity of some sort of transcendent agent can seem attractive, even inevitable.
But does such an explanation even make sense? Suppose I claim that there exists a non-spatial mountain. It’s a mountain – with a sharp summit flanked by steep valleys and crags. Only this mountain is not located or extended in space at all. It does not have spatial dimensions. The mountain transcends our spatial world.
You might well ask me why I suppose there is any such mountain. And if I cannot give you good reasons, you will rightly be sceptical. But actually, isn’t there a rather more fundamental problem with my claim that such a mountain exists? Can’t we know, even before we get to the question of whether there is any evidence for the existence of such a mountain, that there can be no such thing?
For the very idea of a non-spatial mountain makes no sense. My hypothetical mountain has a summit, valleys and cliffs, but these are all features that require spatial extension. A summit requires that one part of the mountain be higher than another. A valley must be lower than the surrounding terrain. The concepts of a mountain, a summit, and so on are concepts that can only sensibly be applied within a spatial context. Strip that context away and we end up talking nonsense.
But if we now turn to the concept of a transcendent designer, does that make any more sense? The concept of an agent has its home within a temporal setting. The concept of an agent is the concept of someone or thing with beliefs and desires on which they might more or less rationally act. But actions are events that happen at particular moments in time. And beliefs and desires are psychological states that have a temporal duration.
Now when we suppose that the spatio-temporal universe was created by God, we are presumably supposing it was a non-temporal agent – an agent that does not (or at least did not then) exist in time. For of course there was not yet any time for the agent to exist in. But if desires are psychological states with temporal duration, how could this agent possess the desire to create the universe? And how did it perform the act of creation if there was not yet any time in which actions might be performed? It is hard to see how talk of a non-temporal agent makes any more sense than talk of a non-spatial mountain.
We might sidestep these puzzles by supposing that God exists, and has always existed, in time. This provides God with the necessary temporal setting in which he might form the desire to produce a universe, draw up a design, and perform the act of creation. But it throws up a host of other puzzles, such as: why did God wait so long before creating the universe (presumably, if God did not have a beginning, an infinitely long time)? And what was he doing in the meantime?
Or we might, as many theists do, insist that talk of an intelligent designer or agent should not be understood literally. They are positing not an agent or designer, but something merely analogous to an agent or designer. But if such talk is to be understood analogically rather than literally, how exactly is it to be understood?
Suppose I claim that there is a non-spatial mountain, because I suppose only the existence of such a mountain can explain certain observed phenomena. My critics point out that the notion of such a mountain makes no sense. I insist they are interpreting me far too crudely and literally. I am talking about something that is merely analogous to a mountain. My appeal to analogy hardly gets me out of trouble, of course, for I now have a duty clearly to explain (i) precisely what my intended analogy is, (ii) how my analogy is supposed to avoid the charge of nonsense that has been levelled at talk of a “non-spatial mountain” understood literally, and also (iii) how this something-that-is-merely-analogous-to-a-mountain is supposed to retain the relevant explanatory powers that a real, spatially-extended mountain would possess. If I cannot supply these explanations, I will likely stand accused of obfuscation and evasion, and with some justification.
The same, of course, goes for those theists who attempt to sidestep the charge of nonsense by maintaining they are being interpreted far too crudely and literally – they are merely invoking something analogous to an intelligent designer. They, too, have much explain. Can they provide the relevant explanations? It is not clear to me that they can. Such appeals to analogy seem to many commentators, myself included, to bring the debate about intelligent design, not up to the level of profundity, but down to the level of obfuscation and evasion.
Why a god? And why that god?
Even if we set all these objections to one side, there remains what is possibly the most damning of all. Which is that it is a huge leap from the conclusion that the universe is the product of an intelligence to the conclusion that this intelligence is, say, the all-powerful and limitlessly benevolent God of love that Christians worship.
As the Templeton-prize-winning physicist Paul Davies points out at the end of his book The Goldilocks Enigma, even setting aside all the other difficulties:
“The other main problem with intelligent design is that identity of the designer need bear no relation at all to the God of traditional monotheism. The “designing agency” can be a committee of gods, for example. The designer can be a natural being or beings, such as an evolved super-mind or super-civilization existing in a previous universe, or in another section of our universe, which made our universe using super-technology. The designer can also be some sort of superdupercomputer simulating this universe. So invoking a super-intellect…is fraught with problems.” P300. The Goldilocks Enigma. Penguin books, London, 2007.
Davies is correct, of course. The even if the supposedly fine-tuned features of the universe did point towards a designer, they no more point towards the existence of the Christian God than they point towards the universe being a computer-generated simulation, or the creation of an earlier super-civilization, or, of course, some other sort of god.