The Beginning of Infinity: Explanations That Transform the World (9 page)

It was similarly harsh to all the other organisms that lived there: few individuals live comfortably or die of old age in the supposedly beneficent biosphere. That is no accident: most populations, of most species, are living close to the edge of disaster and death. It has to be that way, because as soon as some small group, somewhere, begins to have a slightly easier life than that, for any reason – for instance, an increased food supply, or the extinction of a competitor or predator – then its numbers increase. As a result, its other resources are depleted by the increased usage; so an increasing proportion of the population now has to colonize more marginal habitats and make do with inferior
resources, and so on. This process continues until the disadvantages caused by the increased population have exactly balanced the advantage conferred by the beneficial change. That is to say, the new birth rate is again just barely keeping pace with the rampant disabling and killing of individuals by starvation, exhaustion, predation, overcrowding and all those other natural processes.

That is the situation to which evolution adapts organisms. And that, therefore, is the lifestyle in which the Earth’s biosphere ‘seems adapted’ to sustaining them. The biosphere only ever achieves stability – and only temporarily at that – by continually neglecting, harming, disabling and killing individuals. Hence the metaphor of a spaceship or a life-support system, is quite perverse: 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 average rate of extinction since the beginning of life on Earth has been about ten species per year (the number is known only very approximately), becoming much higher during the relatively brief periods that palaeontologists call ‘mass extinction events’. The rate at which species have come into existence has on balance only slightly exceeded the extinction rate, and 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. Genetic evidence suggests that our own species narrowly escaped extinction on at least one occasion. Several species closely related to ours did become extinct. Significantly, the ‘life-support system’ itself wiped them out – by means such as natural disasters, evolutionary changes in other species, and climate change. Those cousins of ours had not invited extinction by changing their lifestyles or overloading the biosphere: on the contrary, it wiped them out because they
were
living the lifestyles that they had evolved to live, and in which, according to the Spaceship Earth metaphor, the biosphere had been ‘supporting’ them.

Yet that still overstates the degree to which the biosphere is hospitable to humans in particular. 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, about such things as tools, weapons, fire and clothing. That knowledge was transmitted from generation to generation not genetically but culturally. Our pre-human ancestors in the Great Rift Valley used such knowledge too, and our own species must have come into existence already dependent on it for survival. As evidence of that, note that I would soon die if I tried to live in the Great Rift Valley in its primeval state: I do not have the requisite knowledge. Since then, there have been human populations who, for instance, knew how to survive in the Amazon jungle but not in the Arctic, and populations for whom it was the other way round. Therefore that knowledge was not part of their genetic inheritance. It was created by human thought, and preserved and transmitted in human culture.

Today, almost the entire capacity of the Earth’s ‘life-support system for humans’ has been provided not
for
us but
by
us, using our ability to create new knowledge. There are people in the Great Rift Valley today who live far more comfortably than early humans did, and in far greater numbers, through knowledge of things like tools, farming and hygiene. The Earth did provide the raw materials for our survival – just as the sun has provided the energy, and supernovae provided the elements, and so on. But a heap of raw materials is not the same thing as a life-support system. It takes knowledge to convert the one into the other, and biological evolution never provided us with enough knowledge to survive, let alone to thrive. In this respect we differ from almost all other species. They do have all the knowledge that they need, genetically encoded in their brains. And that knowledge was indeed provided for them by evolution – and so, in the relevant sense, ‘by the biosphere’. So
their
home environments do have the appearance of having been designed as life-support systems for them, albeit only in the desperately limited sense that I have described. But the biosphere no more provides humans with a life-support system than it provides us with radio telescopes.

So the biosphere is incapable of supporting human life. From the outset, it was only human knowledge that made the planet even marginally habitable by humans, and the enormously increased capacity of our life-support system since then (in terms both of numbers and of security and quality of life) has been entirely due to the creation of
human knowledge. To the extent that we are on a ‘spaceship’, we have never been merely its passengers, nor (as is often said) its stewards, nor even its maintenance crew: we are its designers and builders. Before the designs created by humans, it was not a vehicle, but only a heap of dangerous raw materials.

The ‘passengers’ metaphor is a misconception in another sense too. It implies that there was a time when humans lived unproblematically: when they were provided for, like passengers, without themselves having to solve a stream of problems in order to survive and to thrive. But in fact, even with the benefit of their cultural knowledge, our ancestors continually faced desperate problems, such as where the next meal was coming from, and typically they barely solved these problems or they died. There are very few fossils of old people.

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.

The Principle of Mediocrity is paradoxical too. Since it singles out anthropocentrism for special opprobrium among all forms of parochial misconception, it is itself anthropocentric. Also, it claims that all value judgements are anthropocentric, yet it itself is often expressed in value-laden terminology, such as ‘arrogance’, ‘just scum’ and the very word ‘mediocrity’. With respect to whose values are those disparagements to be understood? Why is arrogance even relevant as a criticism? Also, even if holding an arrogant opinion is morally wrong, morality is supposed to refer only to the internal organization of chemical scum. So how can it tell us anything about how the world
beyond
the scum is organized, as the Principle of Mediocrity purports to do?

In any case, it was not arrogance that made people adopt anthropocentric explanations. It was merely a parochial error, and quite a reasonable one originally. Nor was it arrogance that prevented people from realizing their mistake for so long: they didn’t realize
anything
, because they did not know how to seek better explanations. In a sense
their whole problem was that they were not arrogant
enough
: they assumed far too easily that the world was fundamentally incomprehensible to them.

The misconception that there was once an unproblematic era for humans is present in ancient myths of a past Golden Age, and of a Garden of Eden. The theological notions of
grace
(unearned benefit from God) and
Providence
(which is God regarded as the provider of human needs) are also related to this. In order to connect the supposed unproblematic past with their own less-than-pleasant experiences, the authors of such myths had to include some past transition, such as a Fall from Grace when Providence reduced its level of support. In the Spaceship Earth metaphor, the Fall from Grace is usually deemed to be imminent or under way.

The Principle of Mediocrity contains a similar misconception. Consider the following argument, which is due to the evolutionary biologist Richard Dawkins: Human attributes, like those of all other organisms, evolved under natural selection in an ancestral environment. That is why our senses are adapted to detecting things like the colours and smell of fruit, or the sound of a predator: being able to detect such things gave our ancestors a better chance of surviving to have offspring. But, for the same reason, Dawkins points out, evolution did not waste our resources on detecting phenomena that were never relevant to our survival. We cannot, for instance, distinguish between the colours of most stars with the naked eye. Our night vision is poor and monochromatic because not enough of our ancestors died of that limitation to create evolutionary pressure for anything better. 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. Most phenomena in the universe happen far above or below those scales. Some would kill us instantly; others could never affect anything in the lives of early humans. So, just as our senses cannot
detect
neutrinos or quasars or most other significant phenomena in the cosmic scheme of things, there is no reason to expect our brains to
understand
them. To the extent that they already do understand them, we have been lucky – but a run of luck cannot be expected to continue for long. 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.’

That is a startling – and paradoxical – consequence of the Principle of Mediocrity: it says that all human abilities, including the distinctive ones such as the ability to create new explanations, are necessarily parochial. That implies, in particular, that progress in science cannot exceed a certain limit defined by the biology of the human brain. And we must expect to reach that limit sooner rather than later. Beyond it, the world stops making sense (or seems to). The answer to the question that I asked at the end of
Chapter 2
– whether the scientific revolution and the broader Enlightenment could be a beginning of infinity – would then be a resounding no. Science, for all its successes and aspirations, would turn out to be inherently parochial – and, ironically, anthropocentric.

So here the Principle of Mediocrity and Spaceship Earth converge. They share a conception of a tiny, human-friendly bubble embedded in the alien and uncooperative universe. The Spaceship Earth metaphor sees it as a physical bubble, the biosphere. For the Principle of Mediocrity, the bubble is primarily conceptual, marking the limits of the human capacity to understand the world. Those two bubbles are related, as we shall see. In both views, anthropocentrism is true in the interior of the bubble: there the world is unproblematic, uniquely compliant with human wishes and human understanding. Outside it there are only insoluble problems.

Dawkins would prefer it to be otherwise. As he wrote:

I believe that an orderly universe, one indifferent to human preoccupations, in which everything has an explanation even if we still have a long way to go before we find it, is a more beautiful, more wonderful place than a universe tricked out with capricious ad hoc magic.

Unweaving the Rainbow
(1998)

An ‘orderly’ (explicable) universe is indeed more beautiful (see
Chapter 14
) – though the assumption that to be orderly it has to be ‘indifferent to human preoccupations’ is a misconception associated with the Principle of Mediocrity.

Any assumption that the world is
in
explicable can lead only to
extremely bad explanations. For an inexplicable world is indistinguishable from one ‘tricked out with capricious ad hoc magic’: by definition, no hypothesis about the world outside the bubble of explicability can be a better explanation than that Zeus rules there – or practically any myth or fantasy one likes.

Moreover, since the outside of the bubble affects our explanations of the inside (or else we may as well do without it), the inside is not really explicable either. It seems so only if we carefully refrain from asking certain questions. This bears an uncanny resemblance to the intellectual landscape before the Enlightenment, with its distinction between Earth and heaven. It is a paradox inherent in the Principle of Mediocrity: contrary to its motivation, here it is forcing us back to an archaic, anthropocentric, pre-scientific conception of the world.

At root, the Principle of Mediocrity and the Spaceship Earth metaphor overlap in a claim about
reach
: they both claim that the reach of the distinctively human way of being – that is to say, the way of problem-solving, knowledge-creating and adapting the world around us – is bounded. And they argue that its bounds cannot be very far beyond what it has already reached. Trying to go beyond that range must lead to failure and catastrophe respectively.

Both ideas also rely on essentially the same argument, namely that if there were no such limit, there would be no explanation for the continued effectiveness of the adaptations of the human brain beyond the conditions under which they evolved. Why should one adaptation out of the trillions that have ever existed on Earth have unlimited reach, when all others reach only inside the tiny, insignificant, untypical biosphere? Fair enough: all reach has an explanation. But what if there
is
an explanation, and what if it has nothing to do with evolution or the biosphere?