God and Stephen Hawking (4 page)

In Hawking’s view, a model is a good model if it:

• is elegant;
  

• contains few arbitrary or adjustable elements;
  

• agrees with and explains all existing observations;
  

• makes detailed predictions about future observations that can disprove or falsify the model if they are not borne out.
  ⁵⁷
  

Comparing these criteria with the comments about M-theory above, it is unclear why M-theory is the good model that Hawking appears to think it is. Accounting for the fine-tuning of the cosmos by postulating one intelligent Creator seems much more elegant and economical than postulating 10
⁵⁰⁰
different universes that are unobservable by us, and is surely a much better “model”.

A move to advance the cause of atheism by means of a highly speculative, untestable theory that is not within the zone of evidence-based science, and which, even if it were true, could not dislodge God in any case, is not exactly calculated to impress those of us whose faith in God is not speculative, but testable and well within the zone of evidence-based rational thought.

Modelling reality: the nature of perception

Since Hawking understands M-theory to be a model, it is important to say a few words about Chapter 3 of his book, where he explains his view of mathematical theories as models. Using an analogy of a goldfish that sees the world through the distorting lens of its bowl, Hawking affirms:

Roger Penrose is less convinced by this anti-realism. Referring to Hawking’s stance, he writes: “My own position, on the other hand, is that the issue of ontology is crucial to quantum mechanics, though it raises some matters that are far from being resolved at the present time.”
⁵⁹
In his review of
The Grand Design
he records his antipathy to subjectivity:

Penrose then comments on the “goldfish bowl”:

Hawking’s view of reality is derived from what he thinks about human perception. He says that perception is “not direct, but rather is shaped by a kind of lens, the interpretive structure of our human brains”.
⁶¹
Hawking is now entering one of the most complex and difficult areas of philosophy, the realm of epistemology. Epistemology has to do with theories of knowledge – how we know what we know, and with what justification. Epistemology challenges us to consider how far our prejudices, values, and even our methods of scientific investigation limit or even distort the impressions we receive.

For instance, we see from quantum mechanics that the very means used to investigate elementary particles so affects those particles that the scientist cannot simultaneously determine both the location and the velocity of any one particle. It is also well known that a scientist’s personal world-view can affect the interpretation he places on the results of his experiments, and on the theories he forms.

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:

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.