Although West says he'd like to see urban design's classic theories put to the test and integrated into a scientific framework, he finds his own scientific work as complementary to traditional ways of studying cities. "The thing that makes urban planning so difficult is that the role of design has to be there. That's critical, and it involves things that are outside of science in the traditional sense."
How can these two viewpoints—of science and design—be reconciled? Mehaffy suggests that urban design theory and urban design practice could have a relationship like that of life science research and medicine. A doctor doesn't spend all of his time in a research lab, but he relies on scientific knowledge to guide his decisions on a case-by-case basis. The art comes in the form of tailoring diagnoses and prescriptions for each individual patient.
Marshall says that if urban designers don't build themselves a more scientific foundation, then outside researchers will do it for them. To survive, the field needs to incorporate scientific training into its educational curricula, and cultivate "a concern for testing and validation, critical assimilation of scientific findings from disparate sources, and dissemination of the most reliable, up-to-date findings."
Will the next 50 years be any different from the decades that have passed since Jane Jacobs first cast urban design into pseudoscientific limbo? West thinks that as cities grow and researchers continue to elucidate the influence of design on factors such as carbon dioxide emissions, physical activity and quality of life, there will be an inevitable shift toward scientific thinking. "The city is most important problem we have to face," he says. "What are the underlying principles of urbanization, and what is urbanization going to do to the planet?"