# A letter on optimism about human progress

*This open letter was originally posted on Letter.wiki and is part of a [longer conversation](https://letter.wiki/conversation/202) with Andrew Glover about sustainability and progress.*

Dear Andrew,

Thanks for a thoughtful reply. Reading over it, it seems the biggest difference between us is in our expectations for the future, in a word, our optimism. You agree it would be nice to give everyone the luxuries that only the rich enjoy today, but that “it doesn't seem possible to do this.” In a similar vein, on the topic of energy resources, you say you're “not aware of any principle that says new energy sources will be discovered simply by virtue of humans applying their ingenuity.”

So let's talk about that principle.

Certainly there is no law of physics that mandates inexorable progress, on any one axis or even in aggregate. Progress is not automatic or inevitable.

But human ingenuity has been so successful in such a wide variety of areas that I think, on the grounds of history and philosophy, we are justified in drawing a general principle: *all problems are solvable, given enough time, effort, and thinking.* Or to quote David Deutsch from [*The Beginning of Infinity*](https://rootsofprogress.org/books/the-beginning-of-infinity), “anything not forbidden by the laws of nature is achievable, given the right knowledge.”

To take the historical view first, think of all the problems humanity has solved, all the magic we've created, that seemed impossible until it was invented—not just in energy, but in every field.

Our farms make an abundance of produce spring from the ground—reliably, consistently, year after year, rain or shine, flood or drought, regardless of what weeds, pests, or disease may attack our crops. We do this in many parts of the world, with different terrain, weather patterns, and growing seasons. We have done this not just through soil, fertilizer, and irrigation, but by breeding *better plants*—taking command of the taxonomy of species itself. And when the food is ready, we keep it fresh while it is transported all over the world; produce now knows no season or country.

We have largely conquered infectious disease. Except in the parts of the world too poor for effective water sanitation or mosquito control (and the parts of California where children aren't vaccinated), infectious disease is rare, and usually curable. Less than 200 years ago, we didn't know what caused these diseases or how they spread; today we have identified the specific microorganism behind every major malady, and sequenced their genomes.

The way we travel, too, would seem miraculous to our ancestors from 1800. One of them might have lamented that “it would be nice to give every peasant a fine horse and carriage like the king, but it doesn't seem possible given constraints on resources.” But today almost everyone has access to transportation much faster, safer, and more comfortable than any royalty of old. And not just on land and sea: we have broken the bonds of Earth's gravity to soar with the birds, and higher—to the Moon, and even (through our robot servants) to other worlds. No fear of getting lost, either, with detailed maps of every mile of the globe, and satellites far overhead acting as cosmic lighthouses.

Modern factories are equally amazing, in historical perspective, churning out an incredible variety of cheap products made to exacting specifications that couldn't be matched by the greatest master craftsman working by hand. Before the mechanization of the textile industry starting in the 1700s, it was an incredible luxury to have an entire wardrobe full of colorful, stylish clothes, which you can afford to throw out if they get worn or stained. Just the thought of it may have seemed to people of that era akin to how an expensive mansion or a private jet seems to us today—but we found a way to give it to almost everyone.

And I barely need to remind you of the absolute wizardry of electronics. Even the telegraph was a breakthrough in its day; imagine what Morse, Bell, or Edison would think of the iPhone 11 Pro on a 5G network.

All that is just what we can *do*. Think further of what we *know*. The mysteries we have solved, the secrets of the universe unlocked! We know the structure of matter and the makeup of stars. We detect swirling black holes a billion light years away, and subatomic particles in our own backyard. We synthesize chemicals of our own design. We image individual molecules, and the insides of human beings. We read the very code of life. But before the Scientific Revolution, all of this seemed beyond the range of human comprehension, a domain seen only by God.

When the human mind understands galactic rotation, the periodic table, thermodynamics, electromagnetism, chemical enzymes, the structure of the cell, the evolution of species—when it has solved problems not only in energy, but in transportation, infrastructure, agriculture, medicine, materials and manufacturing, supply chains and logistics, communication and computation, finance and management—why do you think we can't learn the knowledge we need and solve the problems facing us today? How many more examples do you need to increase your confidence in human ingenuity?

*Perhaps* one could look at this incredible track record and count it a lucky historical accident, not to be repeated—if there were no deeper, philosophic way to understand how it came about and what could keep it going. But there is: human beings are, again in Deutsch's words, “universal explainers”. Reason, the conceptual faculty, gives us the upper hand in any contest, even though Nature starts out with the home-field advantage.

It's true that we can't *see* today how we might solve some of the problems we face. But this has *always* been true, and it's the nature of progress. Just because we don't know *how* we'll solve problems, doesn't mean we won't.

That, historically and philosophically, is why I'm optimistic. But surely you know these facts—so why, then, are you relatively uninspired about the future?