The term “city” might typically conjure up images of sidewalks and high-rises, but for School of Architecture professor Elihu Rubin ’99, an urban environment is defined by “the interaction of three faces”: its physical environment, its social context and the power of its institutions.

Thursday evening, Rubin discussed urban design before about 40 people at the School of Architecture’s Rudolph Hall. At the hour-long lecture, titled “The Three Faces of Urbanism,” Rubin laid out his model for the interaction between a city’s physical infrastructure and its social dynamic, using Prudential Financial, Inc.’s work in declining urban areas to illustrate his theory. The School of Architecture sponsored the talk.

Rubin defined the first face of a city, it’s physical landscape, as where the city’s public and private interests interact. A city’s second face, described as the “flow of the human through the physical,” shapes the city’s social dynamic and history, which census takers in turn quantify and artists capture.

As for a city’s third face, one does have to look far to see it, Rubin said.

“It’s the face of power … of your face and my face,” Rubin said. He explained that it is a “realm of agency,” of social power for the individual within the institutional, ideological and economic sphere of urban life.

The third face is one of the more abstract components of his argument, he said, but he reiterated that it cannot be ignored when evaluating a city as a complicated cultural creature.

Once Rubin had established his model of urbanism, he applied the model to the urban initiatives of the national life insurance company Prudential Financial, Inc, which has made a concerted effort to expand its operations into declining urban areas such as Chicago and Boston.

The company, which sells “industrial and working class insurance” and invests in commercial real estate, has distinguished itself as a meeting ground for public and private interests, Rubin said. As it expanded into declining urban areas, the company wanted each new office to have either a park in its back yard or a highway, like a personal driveway, in the front.

After the talk, four attendees said they at first though the title was a bit ambiguous but that they understood it after hearing Rubin speak.

Bahij Chancey ’11 said Rubin did a good job explaining how corporations influence the way urban environments develop.

All six attendees interviewed said Rubin gave a convincing lecture that most in his field would agree with.

Assistant Director of Yale Urban Design Workshop Andrei Harwell, who teaches “Introduction to Urban Design” with Rubin, said Rubin’s topic spoke directly to New Haven as a space of corporate and community development. Harwell said cities like New Haven are often “enclaves of poverty … [with] a problem of self-image,” which depend on this type of corporate influence.

In addition to teaching at the School of Architecture, Rubin is a documentary filmmaker in the field of architecture and city planning. His films include “On Broadway: A New Haven Streetscape” and “Convergence and Other Rituals of the New Haven Green.”