natalie found it

“New York is no place for antiquarians. There are no ruins, and never will be, in New York City. They would be too costly. New York is exactingly different because it insists that you live precisely in the present, with all your capacities stretched to the limit. It is a good city to leave, for in your absence it will continue to live and breathe and grow, and, in its altered state, like a body in which most of the cells have been replaced, it will be ready for you when, as you surely will, you return.”

From New York Days, New York Nights by Stephen Brook (finally finished).