Have you watched television recently? Stored food in a refrigerator? Accessed the Internet? Played games on your smartphone? Driven a car? These are all things that billions of people around the world do every day. And while they are produced by different companies using a wide range of technologies, none of them would be possible without the existence of knowledge.
Knowledge, as I have earlier defined it, is the information that humanity has recorded in a medium and improved over time. As a reminder, there are two crucial parts to this definition. The first is “recorded in a medium,” which allows information to be shared across time and space. The second is “improved over time,” which separates knowledge from information. Improvement is the result of the operation of the critical process, which allows for existing knowledge to be criticized and alternatives to be proposed. Through this process knowledge becomes better at helping us humans meet our needs.
I began this section with examples of everyday technologies that would not exist without knowledge. An even stronger illustration of the power of knowledge is that without it, many of us would not even be here today. As we saw in our discussion of population, Malthus was right about population growth but wrong about its consequences because he did not foresee the development of technological progress powered by improved knowledge.
Let’s look at a specific example of how this process unfolded. Humans breathe air, but for a long time we did not know what it consisted of. Oxygen and nitrogen, the two primary components of air, were not identified as elements until the late eighteenth century.
Separately, although manure had been used in agricultural practice for millennia, it was not properly studied until the early nineteenth century. By the late 19th century, scientists had discovered the microbes that until then were the only way that nitrogen was extracted from the atmosphere and converted into a form that plants can use, a process known as nitrogen fixation. Together that led to the understanding that ammonia, which consists of nitrogen and hydrogen, is a powerful fertilizer. Scientific progress eventually resulted in the Haber process for nitrogen fixation. Invented in the early twentieth century, it became crucial to raising agricultural yields globally, thus averting the dire consequences Malthus had envisaged. Today, about half of the nitrogen in humans bodies has been touched by the Haber process on its way into the plants and animals that we eat .
My simplified history of the discovery of nitrogen fixation doesn’t capture the many false starts along the way. It seems strange to us now, but at one point a leading theory as to why some materials burn was that they all contain a substance called ‘phlogiston,’ which was thought to be released during combustion or ‘dephlogistication.’ Without the improvement of knowledge over time, we might have remained stuck on that theory, failing to find oxygen and nitrogen and thus to increase agricultural yields, and thereby potentially exposing humanity to a Malthusian crisis.
This is just one recent example of a knowledge breakthrough that allowed humanity to overcome a seemingly insurmountable barrier to progress. When thinking about the power of knowledge, we must remember that both our individual lifetimes and the history of modern science to-date are trivially short in the timescale of humanity, which in turn is minuscule compared to that of the universe. When considering longer timeframes, we should regard all speculative technological advances that don’t contravene the laws of physics as possible and eventually achievable. This line of thinking about the power of knowledge is inspired by a theoretical foundation for science recently developed by the physicists David Deutsch and Chiara Marletto called constructor theory .
Consider for a moment what knowledge might allow us to do in the more or less distant future. We might rid ourselves of our dependence on fossil fuels, cure any disease, take care of every human’s basic needs, and travel to other planets in our solar system (organizations like SpaceX and NASA are already working toward this goal ). Eventually, we might even travel to the stars. You might think interstellar travel is impossible, but it isn’t. Extremely difficult? Yes. Requiring technology that doesn’t exist yet? Yes. But impossible? No. It is definitely not imminent, but as constructor theory points out, we can count on it to become possible with the further accretion of knowledge.
We are the only species on Earth that has created knowledge—not just science, but also art. Art allows us to express our hopes and fears, and culture has helped to motivate the large-scale coordination and mobilization of human effort. We might think of the technical component of knowledge as underpinning the ‘how’ of our lives, and the artistic component the ‘why’. If you’ve ever doubted the power of art, just think of the many times throughout history when dictators and authoritarian regimes have banned or destroyed works of art.
Knowledge has already made possible something extraordinary: by means of the innovations of the Industrial Age we can, in principle, meet everyone’s needs. But we need to generate additional knowledge to solve the problems we have introduced along the way, such as the climate crisis. New knowledge does not spring forth fully formed out of the vacuum. Instead it emerges through what I call the ‘knowledge loop’, in which someone learns something and creates something new, which is then shared and in turn serves as the basis for more learning.
The knowledge loop has been around since humans first developed written language, some five thousand years ago. Before that, humans were able to use spoken language, but that limits learning and sharing in terms of both time and space. Since the invention of written language, breakthroughs have accelerated and access to the knowledge loop has broadened. Those include moveable type (around one thousand years ago), the printing press (around five hundred years ago) and more recently the telegraph, radio and television. Now we are in the middle of another fundamental breakthrough: digital technology, which connects all of humanity to the knowledge loop at zero marginal cost, and also allows machines themselves to participate in it.
It is easy to underestimate the potential of digital technology to further accelerate and broaden access to the knowledge loop. To many people, it seems as if these innovations have so far under-delivered. The technology investor Peter Thiel once famously complained that “We wanted flying cars, instead we got 140 characters.” In fact, we have made great progress on flying cars since then, in no small part because digital technologies have already helped accelerate the knowledge loop.
The zero marginal cost and universality of digital technologies are already leading to learning, creating and sharing, giving rise to a digital knowledge loop. And as can be seen in the example of YouTube, it holds both amazing promise and great peril.
YouTube has experienced astounding growth since its launch in beta form in 2005. People around the world now upload over 100 hours of video content to the platform every minute. To illustrate just how much content that is, if you were to spend 100 years watching YouTube 24 hours a day, you would be unable to watch all the videos uploaded in a single week. YouTube contains amazing educational content on topics as diverse as gardening and pure mathematics. Many of those videos illustrate the promise of the digital knowledge loop, but the peril is also clear: YouTube also contains videos that peddle conspiracies, spread misinformation and even incite hate (which may, perversely, be in YouTube’s interests to promote: see “The Misallocation of Attention Through Digital Technology”, below).
Both the promise and the peril are made possible by the same characteristics of the platform: all of the videos are available for free to anyone in the world, and they become available globally the second they are published. Anybody can publish a video, and all you need to access them is an Internet connection and a smartphone. As a result, two to three billion people, almost half of the world’s population, has access to YouTube and can participate in the digital knowledge loop.
These characteristics are found in other systems that similarly show the promise and peril of the digital knowledge loop. Wikipedia, the collectively produced online encyclopedia, is another good example. At its most promising, someone might read an entry and learn the method Pythagoras used to approximate pi, and then create an animation that illustrates this method and publishing it on Wikipedia, making it easier for other people to learn. Wikipedia entries result from collaboration and an ongoing revision process. You can also examine both the history of the page and the conversations about it, thanks to a piece of software known as a ‘wiki’ that keeps track of the history of edits to a page . When the process works, it raises the quality of entries over time. But when there is a coordinated effort at manipulation, Wikipedia can spread misinformation instantly and globally.
Wikipedia illustrates another important aspect of the digital knowledge loop: it allows individuals to participate in extremely small ways. If you wish, you can contribute to Wikipedia by fixing a single typo. If ten thousand people fixed one typo every day, that would be 3.65 million typos a year. If we assume that it takes two minutes to discover and fix a typo, it would take nearly fifty people working full-time for a year (2,500 hours) to fix that many typos.
The example of a Wikipedia spelling correction shows the power of small contributions that add up within the digital knowledge loop. Their peril can be seen on social networks such as Twitter and Facebook, where the small contributions are likes and retweets or reposts to one’s friends or followers. While these tiny actions can amplify high-quality content, they can also spread mistakes, rumors and propaganda: indeed, research carried out at MIT in 2018 found that fake news stories spread faster and more widely than true ones  (see “Freedom to Learn”, below). These information cascades can have significant consequences, ranging from jokes going viral to the outcomes of elections being affected. They have even contributed to major outbreaks of violence, as in the well-known case of the brutal persecution of the Rohingya in Myanmar .
Some platforms make it possible for people to contribute passively to the digital knowledge loop. Waze is a GPS navigation app. It tracks users that seem to be in a car, and the speed at which they are moving. It then passes that information back to its servers, and algorithms figure out where traffic is moving smoothly and where drivers will encounter traffic jams. Waze then proposes alternative routes, taking the traffic into account. If you follow a different route proposed by Waze, you automatically contribute your speed on that detour, a further example of passive contribution. To see the peril of passive contribution, consider Google’s autocomplete for search queries, which are derived from what people frequently search for. As a result, they often reflect existing biases, but they can also amplify them: often, instead of typing out their whole query, users select one of the autocompleted options presented to them.
The promise of the digital knowledge loop is broad access to a rapidly improving body of knowledge. The peril is that it will lead to a post-truth society that is constantly in conflict. Both of these possibilities are enabled by the same characteristics of digital technologies. Here once again, we can see that technology by itself does not determine the future.
To achieve the promise of the digital knowledge loop and sidestep its perils will require human societies to go through a massive transition, on a par with the two previous ones, from the Forager Age to the Agrarian Age and from the Agrarian Age to the Industrial Age. We now need to leave the Industrial Age behind and enter the next one, which I am calling the Knowledge Age. We have based our economies around the job loop, which traps a lot of our attention. We have constructed our laws governing access to information and computation as if they were industrial products. We have adopted a range of beliefs that keep us tied to jobs and consumption, and we are utterly overwhelmed by the new information environment. All of that has to change.
The transition will be difficult, however, because the Industrial Age is a system with many interlocking parts, and systems are highly resistant to change. As we saw earlier, simply harnessing digital technology to the existing system results in a hugely uneven distribution of power, income and wealth. Even worse, it tilts the digital knowledge loop away from its promise and toward its perils.
The human species is facing problems that we can only overcome if we use digital technology to alleviate rather than worsen attention scarcity. We must reap the promise and limit the perils of digital technology for the knowledge loop. In order to successfully negotiate the transition into the Knowledge Age, we need to make dramatic changes in both collective regulation and self-regulation. This is what we will explore in Part Four.