Everything Not Forbidden Is Compulsory

Murray Gell-Mann won a Nobel Prize for his work on the interaction between the physical world's fundamental building blocks. These tiny particles can be combined to create different materials. What kind of combinations are possible? Gell-Mann quipped that "Everything not forbidden is compulsory."

That quip is now known as the "Totalitarian Principle" of quantum mechanics. In simple terms, it means that in a fast-moving evolutionary environment, anything that is not explicitly prevented by the laws of physics (such as conservation of energy or charge) must ultimately occur.

It may sound like Gell-Mann stated the obvious: What can happen will happen. Yet, most people operate on the assumption that only what is likely to happen will happen. The same is true for companies, governments, and other systems.

After all, we are not tiny particles. Our bodies and minds and cities and companies and products are not constantly reshuffled to explore every possible combination. We do not live in the chaotic world of Quantum Mechanics; we live in the orderly world of Newtonian physics, where much larger "bodies" move about in predictable ways.

At least that's where we used to live. For most of human history, the constraints of space and time made the distinction between likely and possible meaningless. A farmer planting vines in prehistoric Mesopotamia was likely to produce X pounds of grapes per hectare, and it was not possible to produce much more under any circumstances. A caveman sneezing in central Europe was likely to infect about X people, and it was not possible to produce much more under any circumstances. A gambler in medieval London was likely to ruin his life — and perhaps burden a few of his friends and relatives — but it was not possible for a single bet to destabilize the whole British or global economy. A good singer in 19th-century Vienna was likely to be heard by thousands of people a year, but it was not possible for her to reach many more.

In the industrial era, we managed to exceed some of the prior constraints, but new constraints emerged to take their place. Mass production was controlled by giant corporations; mass media were controlled by a handful of gatekeepers. And moving around physical goods still required time and money, dampening the speed of change and the feasibility of most ideas.

But something fundamental has changed in recent decades. The constraints that held possible and likely together are collapsing. Now, many more combinations are not just possible, they happen all the time. A programmer launching an app in San Francisco is likely to reach only a handful of customers, but she might reach a billion of them. An office worker sneezing in Wuhan will likely infect only a few colleagues, but he might infect people on five continents within weeks. A mortgage-backed securities trader on Wall Street is likely to ruin his life, but he might spark a global financial crisis. A factory worker uploading a lip-synching video to TikTok will likely be seen by a handful of people, but he might reach hundreds of millions, catapulting a 50-year-old song to the Billboard 100.

What changed? We no longer live in an industrial, linear economy constrained by physical space and time. Our nonlinear economy is dominated by software and stories and biological formulas that spread across elaborate networks with limited friction.

This is not just a world of new winners or new knowledge, but a world that redefines what it means to know and what it means to win. Every victory is ephemeral, every insight is contingent and limited. As soon as something is known, it will be exploited until the knowledge becomes useless. In the past, our knowledge accumulated, and our actions were limited. Now, it is exactly the opposite: Our actions can achieve unlimited outcomes, but knowledge decays rapidly.

This might sound paralyzing, but it's actually liberating. If rigid plans and lasting knowledge are illusions, we are freed from the burden of needing perfect prediction. Instead of trying to master a fixed landscape, the challenge becomes mastering the art of movement on a dancing one.

We must cultivate a portfolio approach to ideas, projects, and even skills, accepting that many will fail while a few might achieve outsized success. Second, we must design for discovery rather than prediction, creating systems (from personal routines to whole cities) that can quickly detect and amplify what works rather than trying to foresee it in advance. Third, we need to focus less on optimization and more on adaptability; the perfect solution for today will be obsolete tomorrow, but the ability to pivot will always remain valuable. And finally, we must hold dearly to what doesn't change: the value of being kind and generous, the benefits of fresh air and sunshine and a nice walk, the importance of friends and family. These are not just "coping mechanisms" to help you deal with volatility; these are important signposts to guide your next business or product.

Yesterday, you needed permission; today, all you need is curiosity, grit, and the chutzpah to test every door that isn’t locked. If it isn’t impossible, someone somewhere will definitely try it. Why not you?

A couple of recent pieces to help you along the way:

• The Nonlinear Economy provides more context on the economic change we are living through.
• Playing Like You're Winning, on the mindset required to succeed in this new environment.

This newsletter was written to myself, but I hope you enjoyed it, too. If you did, please share it.

Have an incredible weekend.

Best,

🎤 How will AI reshape our cities, companies, and careers? My speaking schedule for the spring is filling up. Visit my speaker profile and get in touch to learn more.