top of page
  • Michael Mehaffy

How livable cities (and towns, and suburbs) are key to the human future

The sciences are revealing to us the power of networks - notably including urban networks. As Jane Jacobs, Christopher Alexander and others argued, we need to get this right.

EDITOR'S NOTE: This post is one in a series of discussion topics for the upcoming IMCL conference. Above is a 20-minute talk (click to view), and below is the transcript, by IMCL Executive Director Michael Mehaffy, given at the World Governments Summit on February 13th of this year.

So… I have some good news and some bad news, as the old saying goes!

The bad news is that in this year, 2024, we humans are far from anything like sustainable development. I think you all know what the challenges are – and they are profound. Our 150 year project of industrial modernity is in deep trouble, and it’s clear that profound changes must happen, and will happen – on our terms, or on disagreeable terms forced upon us. So we need to act.

The good news is that we are now able to see, for perhaps the first time in human history, what we must actually do to navigate the daunting transition ahead. We can see it because we now have the scientific understanding of the true nature of our challenges, and the tools we must deploy to meet them.

We are indeed on the frontier of a new industrial revolution – but a revolution that will redefine the very definition of industry, and the very definition of technology.

It will certainly be transformed by artificial intelligence – but even more profoundly, by what artificial intelligence reveals to us about natural intelligence, and the structure of nature – and human nature… and the nature of cities. And that’s what I want to explore with you today.

My own focus is on cities, and the role they play in creating both our challenges and our opportunities. After all, it’s in cities that we move about, interact, create, consume resources, and generate most of our ultimate impacts upon planet Earth. So we need to get this right.

And yes, some of that will involve adding new technologies, since we have always been a technological species. But more deeply, we will need to change our understanding of what cities are, and what they must become.

Let me explain what I mean with the example of the Webb Space Telescope, an astonishing technological feat, deployed flawlessly a million miles from Earth. And it's given us profound new insights into the nature of the Universe.

The Webb Space Telescope, an astonishing accomplishment of human technology, and human exploration.

And by the way, there are now two of these! The European Space Agency also has deployed the Euclid Space Telescope, in the same region of space.

Using similar technology, we may need to deploy solar shields to reduce solar heating, and protect the biosphere from the worst ravages of climate change.

But adding ever more technology to failing technology won’t help us, if we don’t address the deeper nature of the challenge.

More deeply, we will need to understand and exploit the technologies of living systems, the ways they can generate astonishing diversity, beauty, resilience and sustainability. These are the revolutionary new insights coming from the sciences.

And those living systems includes the living system of the brain, and the way it creates deep networks of knowledge and awareness. Neuroscientists call this the "connectome," and it gives us the picture of the world that we see -- not perfect, but useful -- and it provides our intelligence, and even our consciousness. This structure gives us our ability to tell, or to pick out, what is going on in the world. This is the secret of human intelligence. And it’s the secret of artificial intelligence too, the structure known as a neural network.

As you all know, there’s a lot excitement about AI, and considerable worry too, about how this technology will be used – or how it might use US! But there are two key points about AI: First, that it has the ability to assemble vast hyperlinked web-networks of data, or knowledge. And second, it has the ability to evolve and grow more intelligent over time – by itself, the way a child does. This is known as self-organization, and it’s a fundamental property of biological systems.

So the knowledge, or the data, is inter-connected into these vast clusters of web-networks. And they get more and more deeply interconnected over time, with ever more connections, forming “deep networks,” or we could say, “Deep Nets” for short.

We could contrast those with what we might call “Shallow Nets” – with few deep connections, maybe because they’re too new, or they have other problems. I’ll come back to that important point.

Now here’s an amazing thing: the natural world is full of these “deep nets,” from genetic codes, to the structures of proteins, to ecosystems, and much else.

And human language also has this deep-net structure, as we can see in a beautiful piece of poetry. Or in the linguistic knowledge represented, say, by an encyclopedia, with many deep connections between the different topics.

And as we saw, the brain itself has this deep-net structure, in the way it creates deep networks of knowledge and awareness.

And here’s another amazing and wonderful thing: Cities also have this deep-net structure. The spaces of a city also form a very complex adaptive web-network – a “deep net” – at large and small scales. Cities also learn, in effect, and incorporate intelligence, about how to make a successful and desirable place to live.

This idea may seem a bit abstract, so let me give you a concrete example. Below is a montage of a fairly ordinary London street, around the corner from where I used to live as it happens. And you can see many private rooms, but also more public room-like spaces, the little spaces created by terraces or balconies or the sidewalk frontages of buildings. And these room-like spaces are connected to each other in some ways, and often NOT connected in other ways. We can see but not hear through the glass, or hear but not see through the hedge, and so on.

A section of a street in London, UK.

And everything is connected to the street and to the public realm. It’s a remarkably deep web-network of connections, even for this one small section of one street.

And this “place network” is evolving and self-organizing over time, as people make small adaptations to control their desired level of contact and privacy. They close windows, open doors, and over longer spans of time, make major remodels or new buildings entirely.

They make bigger changes over longer times, as I found when I went back to this spot five years later.

There were new businesses and new paint colors, but also, new kinds of spaces, terraces above, a new stoop in front of the door below, and so on.

The same thing happens at even larger scales over longer spans of time, as we can see in the example of Venice over about a century.

Below is a drawing by the Italian architect and morphologist Muratori, and we can see the remarkable transformation and articulation of spaces and their connections… Right down to the ornamental details, developing into the city we all know and love today.

Above: drawing by Saviero Muratori (1959).

A similar bottom-up transformation happens in the natural world, where termites and other insects lay down chemical signals that they then use to build up highly sophisticated structures that control the temperature of their nests. It’s a phenomenon known as “stigmergy,” and it’s not controlled by a central authority – it’s a process of self-organization.

We humans do something similar – we lay down information in our environments, that then shapes further activities and emergent patterns of urban life.

And as the neuroscientists are finding, beauty is also an important form of information – telling us this is a good place, we will be well here, we can thrive here. And perhaps we will care more for that beautiful home, and sustain it for longer.

So, I suspect you can see now that, like brains, cities too can embody a deep form of intelligence, a “deep net” structure – and they can evolve and “learn” to be smarter, about how to provide a place where people can thrive.

Now this new understanding of how cities really work is still not well embedded into our “modern” systems. The remarkable journalist Jane Jacobs gave an early account in the early 1960s, when she described the “organized complexity” of cities.

Around that same time, the architect and theorist Christopher Alexander also pointed out that “a city is not a tree” – not a simple tree-shaped hierarchy, but rather, an interconnected “deep net”.

Alexander’s insight formed the basis of his “pattern language” methodology, which turned out to have surprising usefulness, of all things, in the field of software. And it led to surprising innovations in game design, wiki and Wikipedia, Agile methodology, and many more innovations.

Now you may remember the deep-net structure of encyclopedias that I described earlier, like Wikipedia. So it’s not a coincidence that many AI systems use Wikipedia, and other similar large language datasets, to generate very useful accounts of the world. They all exploit this deep-net structure.

It seems there’s a similar deep-net structure in the way economic expansion occurs in cities, as so-called “knowledge spillovers” connect diverse people within the public realm. Jane Jacobs wrote about this in detail, suggesting it was key to the powerful so-called “agglomeration benefits” of cities.

And this deep-net structure also seems to be the key to the surprising resource efficiencies of cities, especially more compact ones – they work not unlike ecologies, to maximize outputs while reducing and even regenerating resources.

This was a crucial point that Jane Jacobs made, near the end of her life, when she spoke of the coming “age of human capital” – expanding human development, while reducing and renewing natural resources. That is surely a key feature of the coming transition, and a goal of great importance.

So where does this leave us in thinking about the cities of the future?

For one thing, I think it tells us to be very skeptical of mechanical, fantasy-based images of yesterday’s future, that have their roots in the high consumption patterns of the early 20th century, well before our more recent scientific understanding of the deeply interconnected structure of nature, and human nature.

These approaches have not lived up to the fantasies – in fact, they have left us with a legacy that is, in a word, unsustainable.

For another thing, I think the sciences now reveal to us the formerly hidden collective intelligence embodied in the great cities and buildings of the past. It is not the images of these places that we must somehow imitate today. Rather, they embody deep knowledge, deep patterns — “deep nets” — for us to regenerate anew, as a kind of “DNA of place.”

I think this knowledge is very helpful in other ways too. We can now see the danger of what I earlier called “shallow nets” that we might say are “clogging up” the world. They’re producing very damaging outcomes and dysfunctions, in areas as diverse and seemingly unrelated as destructive social media, fake news, and political divisiveness… but also shallow image-based consumerism, the decline of critical institutions, market failures, choking bureaucracy… and unsustainable “externality costs,” as the economists refer to them. All of these trends imperil our civilization, and our future as a species.

I think we can also see it in the specific dysfunctions of urban settlements – for example, the social isolation and health impacts that come from sprawling, disconnected and over-encapsulated urban forms.

We cannot sustain the soaring externality costs that must be devoted to reconnecting people through automobiles and other machinery. And yet these are still dominant models of urbanization even today.

That is one reason why the United Nations’ Sustainable Development Goals, and their cousin, the New Urban Agenda, are so focused on this topic of sustainable urbanism. It is now urgent that we reform our failing paradigm of contemporary urban development, toward something less wasteful, more sustainable, more life-supporting – and by the way, actually more livable and more enjoyable!

Yet there is the uneasy sense today that the world is getting uglier… But perhaps that doesn’t matter, if we can just address the functional problems? Unfortunately, that view is not consistent with new research from neuroscience and other fields, which suggests that our experience of beauty or ugliness is intimately related to our need to find environments that are healthy and supportive of our own health and well-being.

We’re learning that these environments often exhibit forms of mathematical symmetry, not only bilateral but rotational, translational, scaling, and compound forms of symmetry. As Christopher Alexander showed, these symmetries emerge from the natural processes of healthy living growth, including the growth of cities. And when the growth of cities turns malignant, we naturally experience these place as ugly. When we are unable to experience a pleasing symmetry in our environments, evidence suggests that we may suffer a kind of “symmetry deficit disorder.”

So these and other new scientific insights offer us some very helpful new tools and strategies to reform our mistakes, and to transform our cities and towns into more flourishing, beautiful, sustainable and just places, ready to play their role in the great transition ahead.

The new tools include new and better kinds of urban codes, more supportive of informality and healthy growth. They include new economic mechanisms that can better value the growth of human capital, while also valuing the reduction of “externality costs,” including the depletion and emissions of our critical resources. There are promising new models, like the “15-minute city,” “isobenefit urbanism,” and what is called the New Urbanism.

The new tools also incorporate new expressions of the timeless knowledge of great human places and placemaking around the world and through history. We now see that these places embody rich complexities that we are only now beginning to understand and learn from, thanks to the profound new insights from mathematics and the sciences. These structures are ancient, to be sure — but they are also at the cutting edge of modernity and its challenges. And so too is our new understanding of them.

And by the way, below is an image of an entirely new settlement generated on those ancient patterns by ChatGPT 4!

So there is much more to do to develop and apply these lessons, through research and dissemination of practical lessons. That is one key goal of the new Rêve Institute, a center at the new Sorbonne Dubai.

I talked earlier about the deep-net structure of poetry, so let’s close with this thought-provoking passage from T.S. Eliot. Perhaps when it comes to the cities of the future:

We shall not cease from exploration

And the end of all our exploring

Will be to arrive where we started

And know the place for the first time.



bottom of page