How do human beings inhabit the Earth? That is the defining question of our century, since, broadly speaking, the way human beings currently inhabit the Earth is through destroying life and pillaging resources (generally the North pillaging the resources of the South). We talk about this every day on television—but how do human beings concretely inhabit the Earth? The metropolis is a concrete and embodied expression of this ecological catastrophe.

Looking at it like that helps me understand a lot of things. It helps me understand our almost morbid fascination for these landscapes. We’re all a bit drawn to a kind of metropolitan porn. Fascinated by something both serious and problematic, we enjoy peeking behind the scenes at industrial zones. And there’s more than fascination here. After a decade of these walks, there is a deepening ambivalence for metropolitan spaces, because as we have developed narratives of metropolises—as we have set about telling the story of cities—we have, in a sense, become advocates of the metropolis; in other words, our narratives also serve to make the metropolis acceptable, tolerable, and even a bit poetic and interesting, but for some urbanists, the metropolis is toxic and problematic. I think we actually have to learn to embrace this ambivalence: it’s part of what we’re taking on.

Why is walking through metropolises so worthwhile today? Because it puts us face to face with the most concrete embodiment of the most serious issue of our time. What I mean is that civilization has gotten lost and we are exploring the future ruins of our lost civilization. We need to take this very seriously. It also resonates with what’s going on in the social sciences. Across the globe, something sociologists like Bruno Latour have dubbed “symmetrical anthropology” has taken hold. So, we are anthropologists. But we aren’t looking for truths about humans in the origins of humanity—in the civilizations preceding modernity on the other side of the globe—in a kind of reproduction of colonial practices; we aren’t on the hunt for “less advanced” humans, as represented, for instance, by the aborigines. We are interested in symmetrical anthropology as a means of studying ourselves, because human beings have become such a serious problem for the Earth. We are studying what has been left unthought: our own cities and our own neighborhoods. We are looking head on at the most serious issue of our time. When we think about it like that, our collective mission takes on greater weight.