The 110th Floor of the World Trade Center

Michel de Certeau opened "Walking in the City," the most famous chapter of The Practice of Everyday Life, by standing on the 110th floor of the World Trade Center and describing the panoramic view of Manhattan. From that altitude, the city's grid becomes visible—the avenues running north-south, the cross-streets organizing the blocks, the traffic flowing in patterns that resemble the circulation of blood through a designed organism. The view from above is the strategic view: it sees the city as a totality, as a text that can be read, as a system that can be governed. Then de Certeau descended to the street. At street level, the grid disappears. The walker sees the block she is crossing, the corner she is turning, the specific texture of this particular Tuesday morning. She navigates by habit, by memory, by the accumulated embodied knowledge of thousands of previous walks—knowledge the map cannot contain. The walker produces,