Andrea Torreblanca (AT) Today is dedicated to a text called “The City Is Not a Tree.” The title is from a text that Christopher Alexander wrote in 1965, in which he argued that cities cannot be built with a structure of a tree trunk with branches, because in this way the different areas of life cannot intersect. So, instead, he proposed to build cities from a semi-lattice as a way of interweaving the different social, economic, and civic activities that occur in a city, so that the city itself is a receptacle for life.

Alejandro Peimbert (AP) “The City Is Not a Tree” poses from its first paragraphs a dichotomy between the natural city and the artificial city. I would like to pose the question to Gina about the idea of megacity, and of these two layers.

Georgina Cebey (GC) This text is abstract, mathematical, precise, built from axioms. When I work with images what I try to do is to build or identify metaphors and, in that way, I can talk about the city. So, my way of dialoguing with this highly axiomatic text is the idea of the image and how to translate Alexander’s language into the image. This idea of the natural city versus the artificial city seems to me to be a provocation for the moment when Alexander wrote this, when there were already megacities, and a theory of the megacity. I think Alexander is putting the idea forward from patterns, from computer principles that are only a part of the city.

AJ Kim (AJ) I do agree with Alexander that the city is not a tree, but as a planner, I’m always also then thinking about, so what is a city? In reading Alexander’s work, I think that the city is a story. So, I want to name briefly a couple of critiques of Alexander before I go to what resonates with me, because I think it’s important. One is that there is something that feels very colonial about his belief in the importance of beauty, and what kind of beauty are we talking about? There’s also something very colonial about his adherence to the idea of order. And then, the concept of symmetry: I think maybe in architecture it is a more salient concept than it might be in my area of planning, [where] we’re trying to understand how to plan for flexible formations of the city, for informality, and [for] places at the edges. As we’re thinking about Alexander, what I do want to compliment is his kind of embrace of the way in which people will adapt and the way in which buildings become human through their flexible adaptations over time. Maybe Alexander would agree that if the city is a story or the building is a story, then every inhabitant adds to that story over time. But I think that we must talk about issues of class, what we think is ugly. What does the spread of ugliness mean? What does it mean to think about the spread of migrants both here in Mexico and in the United States, and what forms we think that ugly takes. And then maybe perhaps a more philosophical question is, do we not want to design for the ugly or the asymmetrical?

AP Lorenia, regarding this permanent migration in cities like Tijuana and Mexicali, what is your perspective, more than from planning or urbanism, from anthropology?

Lorenia Urbalejo (LU) I would like to think about these northern cities, also from this process of colonization and colonialism. Many times [it was believed] that these were uninhabited places, when there was already a population, a population that was not within the standards and especially the morality of the colonial process. The arrival of the imposition of a way of life also became a way of construction and how to inhabit those spaces. In the course of politics, a certain population is pushed to the margins; there are maquila workers, who cannot stay in certain spaces of the city, because the spaces are not designed for them, and they go through what we call the urban margins. Many things happen there, other religious and cultural practices are energized. And this happens at the same time that processes of self-construction occur, of constructions that create social relations.

GC I agree, I think that urbanism and architecture are colonial devices and control apparatuses. The fact that Alexander came here to build these houses and propose a horizontal exercise is very symptomatic. When Alexander arrived here, the whole country had already developed housing policies sponsored by the state. The state, after Mexican Revolution, dedicated itself to provide housing, to generate corporatism machines, to associate with unions, and to provide housing to those who could be more problematic: an exchange of power and control. And these policies had already reached the north of the country. In Mexicali there were already state housing projects. So, the fact that Alexander arrives here and says: we are going to build in a horizontal way, and we are all going to do it together could be understood as a certain hegemonic order. But I believe that a very interesting counter-hegemonic act also occurred: the agency of the individuals who adapted [the project] to their needs—a crack that points to ruin and entropy. Urbanism and architecture are indeed colonial powers, but Latin America and the global south are fortunately the exception to everything, and here the rules are broken for everything, and the result can be disastrous, but it can also be wonderful.

AJ A question that I have based on observing [Mexicali’s] public spaces and sidewalks, and the edges, is that you have so many more places for people to live. I’m guessing because places are left to be, to exist. I mean, our relationship [in LA] with the state is incredibly fractured: the state produces regulation and policing in the name of protecting the people, so in LA, all of our people are on the street, you know, dying in the heat. And I would imagine there’s quite a bit of that here as well. But from what it looked like, there’s also unstable, ugly, dangerous housing where people can sleep instead of the street, there are places for people to go. The alternative to what we have in the US, which is that there is no place for you to be if you are ugly, disabled, unwell, Black, immigrant... I actually think that there’s so much to learn from Mexicali. There are so many lessons to learn from a type of planning and design that incorporates chaos and allows for people to just be where they can be in the way. And the biggest barrier, I think, in planning is that often we want to put up walls to that. People’s lives are very relevant across the border. I think somebody yesterday used the terms “liquid border,” which was so fascinating to me—a liquid border is something you can’t divide. You have people that have found places to live, primarily because the government ignores them. So as a planner, this is weird for me to advocate in the US what I’m often saying: “Just ignore it.” Do not send police, do not send code enforcement. Do not plan for the city because we are creatures who are trying to make sense of ways of surviving.

LU In Tijuana, for example, we live in permanent insecurity. The social housing developments are failed projects. These subdivisions were contemplated with open streets that we call “cerradas,” and these [were considered] a public space for the people who lived there. But the reality is that the housing policy is quite dehumanized, heartless. It’s not meant for people to gather. They are these tiny spaces where people should be together, but they do their best not to be together. There are conflicts [but] we have to appeal to the collaborative, to solidarity help—to approach other disciplines, such as geography, which has worked a lot on the human scale, psycho- geography, for example.

GC Alexander talks about the figure of the architect. Thinking about how we are going to make everything more human and social is precisely to rethink the figure of the architects; perhaps not as a architects-builders, but rather as activist architects who are committed to what they do and what work they are going to do with the community. Let the architects be the activists, let them go out, let them walk, let them do field work, let them study anthropology. For me that would be the change.