I’ve written this essay in two parts. The first part is general in nature and explores key ideas from David Deutsch’s books The Fabric of Reality and The Beginning of Infinity. The second part examines in depth ideas from “The Spark”, a chapter from The Beginning of Infinity. You may choose to read one or both parts.

It’s easy to be a pessimist. But as Matt Ridley bluntly put it in The Rational Optimist “the bookshops are groaning under ziggurats of pessimism. The airwaves are crammed with doom.” Ridley astutely observes that despite the fear mongering about conflicts in faraway lands delivered on the hourly news or the emotional rage machine that is social media, on all major indicators of human progress, life on earth is becoming more pleasant, not less. Steven Pinker’s book The Better Angels of our Nature: Why Violence Has Declined documents the arc of human progress comprehensively, should you wish to read further.

I am writing this post to show why the pessimists worldviews are actually fraudulent, once you take their ideas seriously.

Every decade pessimists’ tie themselves to a sacred cause on which hangs their doom day spirit. Ridley observes in his lifetime, first “in the 1960s the population explosion and global famine were top of the charts, in the 1970s the exhaustion of resources, in the 1980s acid rain, in the 1990s pandemics, in the 2000s global warming”. And clearly, with the exception of the last one, they are all a footnote to history today.

I will attempt to build on Naval Ravikant and Brett Hall’s recent discussion on why human beings are exceptional. But before I do, here are a few things I agree with Naval and Brett on.

First, as Brett points out, in epistemology (theory of knowledge) humans are the only non-Bayesian reasoners. Secondly, in evolution humans are the only memetic creatures we know of. Ideas can spread fast and can be built on. Thirdly, in the theory of computation, humans are the only universal explainers (aside from the computers we have built).

Alright, back to defeating the pessimists’ world view. Let’s examine their ideas. On the face of it, their ideas seem to have merit. But upon closer examination, we can see that pessimists are actually using Bayesian reasoning to conclude that we are on track for total disaster. What is Bayesian reasoning? Bayesian reasoning is essentially that tomorrow will be like today; that is, the sun rose today and so it shall rise tomorrow too. They are simply extrapolating today’s conditions to predict the future. But the future is relatively unpredictable. Most things are not static. Human beings are knowledge creating machines, capable of solving every possible problem (unless constrained by specific laws of physics). So the pessimists are actually arguing that human beings are not capable of solving these problems through knowledge. And even worse, they are predicting they know the content of all future knowledge. But just as no one in 1900 could have foreseen the innovations of the twentieth century, including whole new fields such as nuclear physics, computer science and biotechnology, our own future will be shaped by knowledge that we cannot foresee today. And fundamentally this is is why the pessimists worldview is wrong: no one has a monopoly on the content of future knowledge.

Deutsch provides a good example of a physicist’s bounded and wrong prediction in 1894 with regard to the future of physics (although it could just as easily have been made today).

“The most important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote..”

– Albert Michelson, University of Chicago, 1894

Here’s another more practical example Deutsch uses to illustrate why the pessimists bounded conception of human beings’ problem-solving capacity is wrong. When colour televisions were initially produced, they required the element europium to luminate the red phosphors on the screen. And at the time Europium was, and still is today, one of the rarest elements on Earth. The planet’s total known reserves would only suffice to build a few hundred million colour televisions. And so the pessimists concluded that, with europium being scarce, the days of colour television would be finite and we would be back to watching tv on monochrome sets. But of course, that is not what transpired. Humans found a different way to transmit colour onto screens. In short, human beings created new knowledge, by substituting europium for liquid crystals, which consists of common elements. And today, LED colour televisions are abundant. So europium was not required to build a colour television after all!

The entire record of human civilisation is littered with proof of human beings problem-solving abilities. The human capacity for knowledge creation is not bounded. That is why today, in most of the world, human beings are not foraging forests for berries or hunting for wild deer in order to sustain themselves. And so Deutsch points out, this goes to the very heart of what people are. In the pessimists worldview, people are wasters: we take precious resources and madly convert them into useless coloured pictures.

The case for optimism

Conversely, optimists believe that people are problem solvers: creators of knowledge and solutions to existing problems. A future post will outline how human beings create knowledge, what Deutsch calls the ‘criteria for reality’. And so optimistic opponents of Malthusian arguments rightly point out that all evils are due to a lack of knowledge, and that all problems are soluble. But of course, one must concede one that we do not know whether the knowledge creation will always occur in time to solve a particular problem (a good argument for speeding up the rate at which we create knowledge!). That seems a reasonable analysis of where the problem of carbon emissions is today. Technology will likely solve for this problem, but can it occur fast enough?

Another great example Deutsch provides in The Beginning of Infinity is with respect to the population debate. He critiques the ‘Paul Ehlrich’ school of overpopulation. Ehrlich’s argument was simply this: humans are rapidly eating up the Earth’s resources. The depletion rate means we will soon run out of resources. Raw materials were running out. Humans were recklessly consuming the Earth’s finite resources; we had created too many power stations and factories, and mines, and intensive farms - too much economic growth, far more than the planet could sustain. And worst of all he argued, there were too many people on the planet and we would soon run out of resources to support any more people (Earth’s population in 1971 when Ehlrich made this prediction was 3.78bn people, less than half of today’s). Ehlrich was a Bayesian. He, like Malthus, was extrapolating contemporaneous data to predict the rate at which resources would decline and thus what the world would be like in the future.

The growth of knowledge cannot change the fact that the possible outcomes, of the future, or their probabilities are also not yet known. And because we know from our theory of knowledge that the ability of scientific theories to predict the future depends on the reach of explanations, we can also safely conclude that no explanation has enough reach to predict the content of its own successors or their effects, or those of other ideas that have not been thought of!

So, in large measure, the future is unwritten. We are its authors. And, in dynamic societies (static societies do exist but are unsustainable over the long-term but more on that in a future post), change is inevitable. And change stems from new knowledge being created in human minds to alter future possibilities. And in this universe, as far as we know, humans are the only knowledge creators. We are, in short, exceptional until proven otherwise.

This ends Part 1. Read Part 2 here.

References:

Brett Hall and Naval Ravikant, Humans are Exceptional

David Deutsch, The Beginning of Infinity

David Deutsch, The Fabric of Reality

Matt Ridley, The Rational Optimist

Steven Pinker, The Better Angels of our Nature: Why Violence Has Declined

World Population Growth, Our World in Data