God and Stephen Hawking Page 5
The aspect of epistemology at issue here is perception. Philosophers seek to understand the actual process that is going on when we perceive something in the external world; and even at this primary level there is already a difference of opinion. At one extreme in the debate stands Naïve, or Direct, Realism. It asserts that, under normal conditions, we have direct perception of the external world. I see a tree, for instance, and I perceive its existence and its qualities simply by looking directly at it, touching it, smelling it even.
At the other extreme in the debate stands the Representative Theory of Perception (RTP). It asserts that we never perceive a tree, or anything else, directly. When we look at a tree, what happens is that our minds receive certain subjective impressions or representations of the tree; and it is these subjective representations – called sense-data – that we directly and most immediately perceive, not the objective tree itself. And it is on these sense-data that we depend for our knowledge of the tree. Some philosophers who espouse this theory liken it to watching a football match, not directly, but on a television screen. But this theory does not claim that we are necessarily conscious of these subjective sense-data, as we would be of a television screen; or that we formally infer from the sense data the existence and the features of the tree. But nonetheless it maintains that this is what is really happening: what we perceive are simply these subjective sense-data, not the tree itself, and our knowledge of the tree is built on them.
The implication of this theory should now be clear. If it were true, we could never check the accuracy of our subjective impressions of the objective world against the objective world itself, because, however much we studied the objective world, we would never perceive it itself, but only some subjective impression of it. We might decide that one set of sense-data was better than another (though by what standard should we judge?); but we could never be sure that any set of sense-data represented the objective reality with complete accuracy.
It would seem that Hawking adopts something very like the Representative Theory of Perception. Now it is simply not possible to branch off into a detailed discussion of epistemology in this book. I shall content myself by coming back to Hawking’s goldfish in a bowl analogy, because it is our visual perception that is often appealed to in order to justify RTP. For instance, a straw in a glass of water looks bent at the surface of the water.
However, concentrating solely on visual perception could be misleading. In addition to our five senses we have reason and memory, and often two or more senses can be applied together. Memory and reason can join them simultaneously to achieve direct and correct perception. Let’s do a simple mental experiment to show that this is so.
Suppose we stand in the middle of a straight railway track. As we look along the track the two rails will appear to converge in the distance, until we can no longer distinguish them. At that moment our sense-data will record that they have coalesced. Presently a train comes up behind us. We step out of the way and the train goes by. As it recedes into the distance the train appears to get smaller and, according to RTP, our sense-data will duly record an ever-diminishing train.
But now reason and memory come into play. Reason tells us that locomotives cannot get smaller just by travelling (unless they approach the speed of light!); and memory of trains on which we have travelled reminds us that trains don’t get smaller as they proceed. So now, although our visual perception sees the train getting smaller, we know that it is actually the same size as when it passed us. That means that, as we watch the train reach the distant point where the rails looked as if they coalesce (and still do in our sense-data), we can use the known size of the locomotive as a means of measuring the distance between the two rails at that point, and know with total confidence that, in spite of appearance, the rails are the same distance apart there as where we are standing.
Moreover, all this is going on in our heads simultaneously. Initial visual perception suggested that the rails were coalescing. Now visual perception allows us to see what happens when the train reaches the point of apparent coalescence: we can see that the train does not come to a halt but keeps going. Simultaneously, reason perceives with absolute certainty that the rails cannot have coalesced but are as far apart as usual. In other words, it is not necessarily true that vision always produces subjective sense-data which reason subsequently turns into valid concepts, as one version of RTP suggests. In a knowledgeable person, reason and memory can work alongside vision to help achieve the true perception of objective reality.
Commenting on RTP, philosopher Roger Scruton writes:
It seems to say that we perceive physical objects only by perceiving something else, namely, the idea or image that represents them. But then, how do we perceive that idea or image? Surely we shall need another idea, which represents it to consciousness, if we are to perceive it? But now we are embarked on an infinite regress. Wait a minute, comes the reply; I didn’t say that we perceive mental representations as we perceive physical objects. On the contrary, we perceive the representations directly, the objects only indirectly. But what does that mean? Presumably this: while I can make mistakes about the physical object, I cannot make mistakes about the representation, which is, for me, immediately incorrigible, self-intimating – part of what is “given” to the consciousness. But in that case, why say that I perceive it at all? Perception is a way of finding things out; it implies a separation between the thing perceiving and the thing perceived, and with that separation comes the possibility of error. To deny the possibility of error is to deny the separation. The mental representation is not perceived at all; it is simply part of me. Put it another way: the mental representation is the perception. In which case, the contrast between direct and indirect perception collapses. We do perceive physical objects, and perceive them directly…And we perceive physical objects by having representational experiences.62
In other words, there is no third, intermediate and quasi-independent thing called sense-data between our perception and objects in the external world. The sense-data, or representations, are our perception of the external world; and that perception of the world is direct. That does not mean, of course, that direct perception is never mistaken. The fact is that, when it comes to using our senses to gain information about the external, objective world, human beings have had to learn to use their five senses correctly, and interpret the information correctly. Each one of us has to do so individually. Someone may hear a musical sound, as sound-waves enter his ear and then his brain, and yet misjudge the musical instrument from which it has come. Experience, sight, instruction, and memory will all be necessary before he can immediately recognize the instrument. But that doesn’t mean that originally he didn’t hear the sound directly. A person recently blinded will need to develop an increasingly sensitive touch in order to read Braille. And, since light behaves in the way we now know it does, we have to learn to see and how to gather correct information from eyesight. From time to time we can misinterpret what we see, hear, touch, taste and smell, and we have to learn to use our senses with greater discernment. But none of this means that we cannot have direct perception of anything at all in the external world, whatever additional difficulties we may have at the quantum level.
Finally, if we cannot directly perceive that Hawking and Mlodinow are objectively real people who have written a book called The Grand Design, which makes certain truth claims about the universe, then one would wonder why they bothered to write it in the first place. And that is just the interesting thing about those who espouse various kinds of relativism: they all seem to end up by saying, essentially, that truth, perception, etc. are relative, except of course the truth they are passionately trying to get us to perceive. That is, they fail to apply their own relativism to themselves.
The subjective element in science
It is, of course, important to recognize that there is a subjective element in science. The idea of a completely independent observer, free of all preconceived theories, doing i
nvestigations and coming to unbiased conclusions that constitute absolute truth, is simply a myth. For, in common with everyone else, scientists have preconceived ideas, indeed world-views, that they bring to bear on every situation. Furthermore, they are well aware that it is almost impossible for them to make any kind of observation without resting on some prior theory; for example, they cannot even take a temperature without having an underlying theory of heat. Also, their scientific theories tend to be underdetermined by the data; that is, more than one theory could account for the same set of data. If, for example, we plot our observational data on a graph as a finite set of points, elementary mathematics will tell us that there is no limit to the number of curves that we can draw through that particular set of points. That is, the data represented by the points on the paper do not determine the curve that we should draw through them, although in any particular case, there may well be physical principles that significantly restrict our choice.
Most scientists will freely admit, therefore, that science, by its very nature, possesses an inevitable degree of tentativeness. It needs to be made clear, however, that the degree of this tentativeness is extremely small in the vast majority of cases. The fact is that science-based technology has been spectacularly successful in fundamentally changing the face of the world: from radio and television to computers, aircraft, space probes, X-rays and artificial hearts. It is sheer nonsense, therefore, to assert, as postmodernists often do, that these elements of tentativeness and subjectivity in science mean that science is a purely social construct. As physicist Paul Davies says:
Of course, science has a cultural aspect; but if I say that the planets moving around the sun obey an inverse-square law of gravitation and I give a precise mathematical meaning to that, I think it is really the case. I don’t think it is a cultural construct – it’s not something we have invented or imagined just for convenience of description – I think it’s a fact. And the same for the other basic laws of physics.63
It is self-evident, surely, that if we believed that the science that led to the construction of jet aircraft was merely a subjective social construct, none of us would ever get on a plane. Or, to put it another way, one sure method of finding out whether the law of gravity is a social or cultural construct or not would be to step off the top of a skyscraper!
4 Whose design is it anyway?
In the final chapter of their book, Hawking and Mlodinow discuss the “Grand Design”. They open the chapter by saying that although the laws of nature tell us how the universe behaves, they do not answer the why questions they posed at the start of the book: Why is there something rather than nothing? Why do we exist? Why this particular set of laws and not another?64 So far, so good. The laws of nature do not answer the why questions. However, as we saw in Chapter 2, the conclusion of the book contradicts this by affirming that the laws of nature, and in particular the law of gravity, do provide the answer to these questions.
To make sure we have got this right, let us remind ourselves of that conclusion: “Because there is a law like gravity the universe can and will create itself from nothing…Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist.”65 There it is in black and white. The law of gravity is the answer to the very questions that Hawking says it cannot answer.
Furthermore, what does Hawking mean by “spontaneous creation”? It sounds very much like an uncaused cause, an expression often cited as a paradoxical way of describing God. And, even if there were such a thing as spontaneous creation it would scarcely be a reason, would it? A reason would be something that replaced the dots in the statement “There is something rather than nothing because…”. Hawking’s statement seems to be saying: “There is something rather than nothing because there is something – and that something comes about spontaneously without any cause or reason except, maybe, that it is possible and just happens.”
It is hard to be impressed by this kind of argument – especially when it is compounded by the multiple self-contradictions mentioned earlier.
If, on the other hand, we turn to God as the answer to the why questions, as I unashamedly do, then Hawking will counter: “It is reasonable to ask who or what created the universe, but if the answer is God, then the question has merely been deflected to that of who created God.”66
Well, what is sauce for the goose is sauce for the gander. If the answer is “the law of gravity” (which, as we have already seen in Chapter 2, it cannot be), by Hawking’s own argument the question has merely been deflected to: who created the law of gravity? And this is a question that he does not answer.
Hawking is here giving an argument that serves only to reveal the inadequacy of his concept of God. To ask the question who created God logically presupposes that God is a created entity. That is certainly not the Christian – nor, indeed, the Jewish or Muslim – concept of God. God is eternal; he is the ultimate reality, the ultimate fact. To ask who created him is to show that one does not understand the nature of his being.67
Austin Farrer comments aptly on what is at stake here: “The issue between the atheist and the believer is not whether it makes sense to question ultimate fact, it is rather the question: what fact is ultimate? The atheist’s ultimate fact is the universe; the theist’s ultimate fact is God.”68 Maybe we should modify this to say that for some atheists the ultimate fact is the multiverse, or the law of gravity, but this makes no difference to the point at issue.
The bulk of Hawking’s final chapter is devoted to an example of a mathematical model that, according to him, creates a reality of its own: John Conway’s “Game of Life”. Conway envisioned a “world” consisting of an array of squares like a chess board, but extending indefinitely in all directions. Each square can be in one of two states, “alive” or “dead”, represented by the squares being coloured green or black respectively. Each square has eight neighbours (up, down, left, right and four on the diagonals). Time moves in discrete steps. You start with any chosen arrangement of alive and dead squares; there are three rules or laws that determine what happens next, all proceeding deterministically from the initial chosen state. Some simple patterns remain the same, others change for several generations and then die out; yet others return to their original form after several generations and then repeat the process indefinitely. There are “gliders”, consisting of five alive squares, which morph through five intermediate shapes and then return to their original shape, albeit displacing one square along the diagonal. And there are many more sophisticated forms of behaviour exhibited by more complex initial configurations.
Part of Conway’s world (remember that it is assumed infinite in all directions) can be modelled on a computer, so that one can watch what happens as generation succeeds generation. For instance, “gliders” can be observed crawling diagonally across the screen.69
This world with its simple laws holds great attraction for mathematicians, and has been instrumental in the development of the important theory of cellular automata. Conway and his students, as Hawking points out, showed that there are complex initial configurations that self-replicate under the laws. Some of them are so-called Universal Turing Machines that can, in principle, carry out any calculation that could be carried out on a computer. Configurations of alive and dead squares in Conway’s world that are able to do this have been calculated as being of enormous size – consisting of trillions of squares.70
As a mathematician, I find Conway’s work fascinating. Listening to him make mathematics come alive was one of the high points of my experience of Cambridge lectures. However, what interests me here is Hawking’s purpose in using this analogy:
The example of Conway’s Game of Life shows that even a very simple set of laws can produce complex features similar to those of life. There must be many sets of laws with this property. What picks out the fundamental laws (as opposed to the apparent laws) that govern our universe? As in Conway’s universe, the laws of our universe determine the evolut
ion of the system given the state at any one time. In Conway’s world we are the creators – we choose the initial state of the universe by specifying objects and their positions at the start of the game.
Hawking continues: “In a physical universe, the counterparts of objects such as gliders in the Game of Life are isolated bodies of matter.”71
At this point Hawking diverts from the Game of Life, and leaves the reader uncertain as to exactly how he is applying it. Nevertheless, one can surely say that the impression has been communicated to the reader that, just as in Conway’s world a simple set of laws can produce lifelike complexity, in our world a simple set of laws could produce life itself.
However, the analogy shows nothing of the sort, but rather the exact opposite. First of all, in Conway’s world the laws do not produce the complex self-replicating objects. Laws, as we have constantly emphasized, create nothing in any world: they can only act on something that is already there. In Conway’s world the immensely complex objects that can self-replicate under the laws have to be initially configured in the system by highly intelligent mathematical minds. They are created neither from nothing nor by chance, but by intelligence. The same applies to the laws.
Secondly, Conway’s world has to be implemented, and this is done using sophisticated computer hardware with all its attendant software and high-speed algorithms. The alive and dead cells are represented by pixellated squares on a screen, and the laws governing their behaviour are programmed into the system. It should go without saying – but it clearly needs to be said – that all of this involves massive intellectual activity and input of information.