The Beginning of Infinity: Explanations That Transform the World (11 page)

So human reach is essentially the same as the reach of explanatory knowledge itself. An environment is within human reach if it is possible to create an open-ended stream of explanatory knowledge there. That means that if knowledge of a suitable kind were instantiated in such
an environment in suitable physical objects, it would cause itself to survive and would then continue to increase indefinitely. Can there really be such an environment? This is essentially the question that I asked at the end of the last chapter –
can this creativity continue indefinitely?
– and it is the question to which the Spaceship Earth metaphor assumes a negative answer.

The issue comes down to this: if such an environment can exist, what are the minimal physical features that it must have? Access to
matter
is one. For example, the trick of extracting oxygen from moon rocks depends on having compounds of oxygen available. With more advanced technology, one could manufacture oxygen by transmutation; but, no matter how advanced one’s technology is, one still needs raw materials of some sort. And, although mass can be recycled, creating an open-ended stream of knowledge depends on having an ongoing supply of it, both to make up for inevitable inefficiencies and to make the additional memory capacity to store new knowledge as it is created.

Also, many of the necessary transformations require
energy
: something must power conjectures and scientific experiments and all those manufacturing processes; and, again, the laws of physics forbid the creation of energy from nothing. So access to an energy supply is also a necessity. To some extent, energy and mass can be transformed into each other. For instance, transmuting hydrogen into any other element releases energy through nuclear fusion. Energy can also be converted into mass by various subatomic processes (but I cannot imagine naturally occurring circumstances in which those would be the best way of obtaining matter).

In addition to matter and energy, there is one other essential requirement, namely
evidence
: the information needed to test scientific theories. The Earth’s surface is rich in evidence. We happened to get round to testing Newton’s laws in the seventeenth century, and Einstein’s in the twentieth, but the evidence with which we did that – light from the sky – had been deluging the surface of the Earth for billions of years before that, and will continue to do so for billions more. Even today we have barely begun to examine that evidence: on any clear night, the chances are that your roof will be struck by evidence falling from the sky which, if you only knew what to look for and how, would win you a Nobel prize. In chemistry, every stable element that exists
anywhere is also present on or just below the Earth’s surface. In biology, copious evidence of the nature of life is ubiquitous in the biosphere – and within arm’s reach, in our own DNA. As far as we know, all the fundamental constants of nature can be measured here, and every fundamental law can be tested here. Everything needed for the open-ended creation of knowledge is here in abundance, in the Earth’s biosphere.

And the same is true of the moon. It has essentially the same resources of mass, energy and evidence as the Earth has. Parochial details differ, but the fact that humans living on the moon will have to make their own air is no more significant than the fact that laboratories on Earth have to make their own vacuum. Both tasks can be automated so as to require arbitrarily little human effort or attention. Likewise, because humans are universal constructors,
every
problem of finding or transforming resources can be no more than a transient factor limiting the creation of knowledge in a given environment. And therefore matter, energy and evidence are the only requirements that an environment needs to have in order to be a venue for open-ended knowledge creation.

Though any particular problem is a transient factor, the condition of having to solve problems in order to survive and continue to create knowledge is permanent. I have mentioned that there has never been an unproblematic time for humans; that applies as much to the future as to the past. Today on Earth, in the short run, there are still countless problems to be solved to eliminate even starvation and other forms of extreme human suffering that date back to prehistory. On a timescale of decades, we shall be faced with choices to make substantial modifications to the biosphere, or to keep it the same, or anything in between. Whichever option we choose, it will be a project of planet-wide control, requiring the creation of a great deal of scientific and technological knowledge as well as knowledge about how to make such decisions rationally (see
Chapter 13
). In the even longer run, it is not only our comfort and aesthetic sensibilities, and the suffering of individuals, that are problematic, but, as always, the survival of our species. For instance, at present during any given century there is about one chance in a thousand that the Earth will be struck by a comet or asteroid large enough to kill at least a substantial proportion of all human beings. That means that a typical child born in the United States today is more
likely to die as a result of an astronomical event than a car accident. Both are very low-probability events, but, unless we create a great deal more scientific and technological knowledge than we have now, we shall have no defence against those and other forms of natural disaster that must, eventually, strike. Arguably there are more immediate existential threats too – see
Chapter 9
.

Setting up self-sufficient colonies on the moon and elsewhere in the solar system – and eventually in other solar systems – will be a good hedge against the extinction of our species or the destruction of civilization, and is a highly desirable goal for that reason among others. As Hawking has said:

I don’t think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I’m an optimist. We will reach out to the stars.

Daily Telegraph
, 16 October 2001

But even that will be far from an unproblematic state. And most people are not satisfied merely to be confident in the survival of the
species
: they want to survive personally. Also, like our earliest human ancestors, they want to be free from physical danger and suffering. In future, as various causes of suffering and death such as disease and ageing are successively addressed and eliminated, and human life spans increase, people will care about ever longer-term risks.

In fact people will always want still more than that: they will want to make progress. For, in addition to threats, there will always be problems in the benign sense of the word: errors, gaps, inconsistencies and inadequacies in our knowledge that we wish to solve – including, not least, moral knowledge: knowledge about
what to want
, what to strive for. The human mind seeks explanations; and now that we know how to find them, we are not going to stop voluntarily. Here is another misconception in the Garden of Eden myth: that the supposed unproblematic state would be a
good
state to be in. Some theologians have denied this, and I agree with them: an unproblematic state is a state without creative thought. Its other name is death.

All those kinds of problem (survival-related, progress-related, moral, and sheer-curiosity-driven problems) are connected. We can, for instance, expect that our ability to cope with existential threats will
continue to depend on knowledge that was originally created for its own sake. And we can expect disagreements about goals and values always to exist, because, among other reasons, moral explanations depend partly on facts about the physical world. For instance, the moral stances in the Principle of Mediocrity and the Spaceship Earth idea depend on the physical world not being explicable in the sense that I have argued it must be.

Nor will we ever run out of problems. The deeper an explanation is, the more new problems it creates. That must be so, if only because there can be no such thing as an ultimate explanation: just as ‘the gods did it’ is always a bad explanation, so any other purported foundation of all explanations must be bad too. It must be easily variable because it cannot answer the question: why that foundation and not another? Nothing can be explained only in terms of itself. That holds for philosophy just as it does for science, and in particular it holds for
moral
philosophy: no utopia is possible, but only because our values and our objectives can continue to improve indefinitely.

Thus fallibilism alone rather understates the error-prone nature of knowledge-creation. Knowledge-creation is not only
subject
to error: errors are common, and significant, and always will be, and correcting them will always reveal further and better problems. And so the maxim that I suggested should be carved in stone, namely ‘The Earth’s biosphere is
incapable
of supporting human life’ is actually a special case of a much more general truth, namely that, for people,
problems are inevitable
. So let us carve
that
in stone:

It is inevitable that we face problems, but no particular problem is inevitable. We survive, and thrive, by solving each problem as it comes
up. And, since the human ability to transform nature is limited only by the laws of physics, none of the endless stream of problems will ever constitute an impassable barrier. So a complementary and equally important truth about people and the physical world is that
problems are soluble
. By ‘soluble’ I mean that the right knowledge would solve them. It is not, of course, that we can possess knowledge just by wishing for it; but it is in principle accessible to us. So let us carve that in stone too:

That
progress
is both possible and desirable is perhaps the quintessential idea of the Enlightenment. It motivates all traditions of criticism, as well as the principle of seeking good explanations. But it can be interpreted in two almost opposite ways, both of which, confusingly, are known as ‘perfectibility’. One is that humans, or human societies, are capable of attaining a state of supposed perfection – such as the Buddhist or Hindu ‘nirvana’, or various political utopias. The other is that every attainable state can be indefinitely improved. Fallibilism rules out that first position in favour of the second. Neither the human condition in particular nor our explanatory knowledge in general will ever be perfect, nor even approximately perfect. We shall always be at the
beginning
of infinity.

These two interpretations of human progress and perfectibility have historically inspired two broad branches of the Enlightenment which, though they share attributes such as their rejection of authority, are so different in important respects in that it is most unfortunate that they share the same name. The utopian ‘Enlightenment’ is sometimes called the Continental (European) Enlightenment to distinguish it from the more fallibilist British Enlightenment, which began a little earlier and
took a very different course. (See, for instance, the historian Roy Porter’s book
Enlightenment
.) In my terminology, the Continental Enlightenment understood that problems are soluble but not that they are inevitable, while the British Enlightenment understood both equally. Note that this is a classification of ideas, not of nations or even individual thinkers: not all Enlightenment thinkers belong wholly to one branch or the other; nor were all thinkers of the respective Enlightenments born in the eponymous part of the world. The mathematician and philosopher Nicholas de Condorcet, for instance, was French yet belonged more to what I am calling the ‘British’ Enlightenment, while Karl Popper, the twentieth century’s foremost proponent of the British Enlightenment, was born in Austria.

The Continental Enlightenment was impatient for the perfected state – which led to intellectual dogmatism, political violence and new forms of tyranny. The French Revolution of 1789 and the Reign of Terror that followed it are the archetypal examples. The British Enlightenment, which was evolutionary and cognizant of human fallibility, was impatient for institutions that did not stifle gradual, continuing change. It was also enthusiastic for small improvements, unbounded in the future. (See, for instance, the historian Jenny Uglow’s book
Lunar Men
.) This is, I believe, the movement that was successful in its pursuit of progress, so in this book when I refer to ‘the’ Enlightenment I mean the ‘British’ one.