The Beginning of Infinity: Explanations That Transform the World

by David Deutsch

Whenever there has been progress, there have been influential thinkers who denied that it was genuine, that it was desirable, or even that the concept was meaningful.

In this book I argue that all progress, both theoretical and practical, has resulted from a single human activity: the quest for what I call good explanations.

That unboundedness is the ‘infinity’ referred to in the title of this book.

As for the Milky Way, you will be told that, despite its insubstantial appearance, it is the most massive object that we can see with the naked eye: a galaxy that includes stars by the hundreds of billions, bound by their mutual gravitation across tens of thousands of light years.

But we do know that a supernova devastates all the planets that may be orbiting it, wiping out all life that may exist there – including any intelligent beings, unless they have technology far superior to ours.

Yet we owe our existence to supernovae: they are the source, through transmutation, of most of the elements of which our bodies, and our planet, are composed.

Yet it all proceeds according to elegant laws of physics that we understand in some depth. I do not know which is more awesome: the phenomena themselves or the fact that we know so much about them.

Either way, the discoverer of knowledge is its passive recipient, not its creator.

that was not properly understood until the mid twentieth century with the work of the philosopher Karl Popper.

Discovering a new explanation is inherently an act of creativity.

So it is fallibilism, not mere rejection of authority, that is essential for the initiation of unlimited knowledge growth – the beginning of infinity.

We never know any data before interpreting it through theories.

Consider the nerve signals reaching our brains from our sense organs. Far from providing direct or untainted access to reality, even they themselves are never experienced for what they really are – namely crackles of electrical activity.

We do not just see blue: we see a blue sky up there, far away. We do not just feel pain: we experience a headache, or a stomach ache. The brain attaches those interpretations – ‘head’, ‘stomach’ and ‘up there’ – to events that are in fact within the brain itself.

So we perceive nothing as what it really is. It is all theoretical interpretation: conjecture.

In short, they wanted to create knowledge, in order to make progress, but they did not know how.

Then a powerful new mode of discovery and explanation emerged, which later became known as science.

What was needed for the sustained, rapid growth of knowledge was a tradition of criticism. Before the Enlightenment, that was a very rare sort of tradition: usually the whole point of a tradition was to keep things the same.

Instrumentalism is one of many ways of denying realism, the commonsense, and true, doctrine that the physical world really exists, and is accessible to rational inquiry.

Since theories can contradict each other, but there are no contradictions in reality, every problem signals that our knowledge must be flawed or inadequate.

Amending the ‘data’, or rejecting some as erroneous, is a frequent concomitant of scientific discovery, and the crucial ‘data’ cannot even be obtained until theory tells us what to look for and how and why.

Long before the Enlightenment, there were individuals who sought good explanations. Indeed, my discussion here suggests that all progress then, as now, was due to such people.

That is what makes good explanations essential to science: it is only when a theory is a good explanation – hard to vary – that it even matters whether it is testable.

When a formerly good explanation has been falsified by new observations, it is no longer a good explanation, because the problem has expanded to include those observations.

Conjectures are the products of creative imagination. But the problem with imagination is that it can create fiction much more easily than truth.

Realism The idea that the physical world exists in reality, and that knowledge of it can exist too.

Good/bad explanation An explanation that is hard/easy to vary while still accounting for what it purports to account for.

Appearances are deceptive. Yet we have a great deal of knowledge about the vast and unfamiliar reality that causes them, and of the elegant, universal laws that govern that reality. This knowledge consists of explanations: assertions about what is out there beyond the appearances, and how it behaves.

The real source of our theories is conjecture, and the real source of our knowledge is conjecture alternating with criticism.

Some people become depressed at the scale of the universe, because it makes them feel insignificant. Other people are relieved to feel insignificant, which is even worse.

The universe is not there to overwhelm us; it is our home, and our resource. The bigger the better.

When the astronomer Jocelyn Bell discovered pulsars (extremely dense stars that emit regular bursts of radio waves), this is what she was looking at:

Only through a sophisticated chain of theoretical interpretation could she ‘see’, by looking at that shaky line of ink on paper, a powerful, pulsating object in deep space, and recognize that it was of a hitherto unknown type.

But the fact is that progress requires the application of ever more knowledge in advance of our observations.

Scientific truth consists of such correspondence between theories and physical reality.

Like conjuring tricks in reverse, such instruments fool our senses into seeing what is really there.

human beings, on Earth, have dug up raw materials such as iron ore and sand, and have rearranged them – still on Earth – into complex objects such as radio telescopes, computers and display screens, and now, instead of looking at the sky, they look at those objects.

The growth of knowledge consists of correcting misconceptions in our theories.

Like the spaceship, the biosphere recycles all waste and, using its capacious nuclear power plant (the sun), it is completely self-sufficient.

People are significant in the cosmic scheme of things; and The Earth’s biosphere is incapable of supporting human life.

Cold, dark and empty. That unimaginably desolate environment is typical of the universe – and is another measure of how untypical the Earth and its chemical scum are, in a straightforward physical sense.

Nearly the whole of the Earth’s biosphere in its primeval state was likewise incapable of keeping an unprotected human alive for long. It would be much more accurate to call it a death trap for humans rather than a life-support system.

when humans design a life-support system, they design it to provide the maximum possible comfort, safety and longevity for its users within the available resources; the biosphere has no such priorities.

Nor is the biosphere a great preserver of species. In addition to being notoriously cruel to individuals, evolution involves continual extinctions of entire species.

the net effect is that the overwhelming majority of species that have ever existed on Earth (perhaps 99.9 per cent of them) are now extinct.

The first people to live at the latitude of Oxford (who were actually from a species related to us, possibly the Neanderthals) could do so only because they brought knowledge with them,

That knowledge was transmitted from generation to generation not genetically but culturally.

The moral component of the Spaceship Earth metaphor is therefore somewhat paradoxical. It casts humans as ungrateful for gifts which, in reality, they never received. And it casts all other species in morally positive roles in the spaceship’s life-support system, with humans as the only negative actors. But humans are part of the biosphere, and the supposedly immoral behaviour is identical to what all other species do when times are good – except that humans alone try to mitigate the effect of that response on their descendants and on other species.

So Dawkins argues – and here he is invoking the Principle of Mediocrity – that there is no reason to expect our brains to be any different from our eyes in this regard: they evolved to cope with the narrow class of phenomena that commonly occur in the biosphere, on approximately human scales of size, time, energy and so on.

Hence Dawkins agrees with an earlier evolutionary biologist, John Haldane, who expected that ‘the universe is not only queerer than we suppose, but queerer than we can suppose.’