JACOBS’ ATTACK ON URBANRATIONALISM Jacobs recognized the rationalist mindset of those, such as Le Cobusier,whom she criticized: ‘The practitioners and teachers of this discipline (ifsuch it can be called) have ignored the study of success and failure in reallife, have been incurious about the reasons for unexpected success, and areguided instead by principles derived from the behavior and appearance of towns,suburbs, tuberculosis sanatoria, fairs, and imaginary dream cities—fromanything but cities themselves’ (1992 1961, p. 6). Jacobs also saw that therationalist planner, despite his pretension of working only from firstprinciples, in reality, as Oakeshott contended, unconsciously draws upon sometradition or other in devising his schemes. Jacobs’ point here is that theseplanners turned to inappropriate traditions—and to abstractions drawn fromthose inappropriate traditions—since they refused to admit that they wereworking from a tradition at all. As Jacobs saw it, the fundamental problem thatall great cities solve is how to get very large numbers of strangers withvastly different beliefs, knowledge, and tastes to live peacefully together.
Jacobs explains how this is possible without central direction. Great citiesharness the diverse “locality knowledge” (Jacobs, 1992 1961, p. 418) of eachof its individual inhabitants.
(This point, of course, is essentially identicalto Hayek’s emphasis on “how valuable an asset in all walks of life is knowledgeof people, of local conditions, and of special circumstances” (1945, H.9) Whatplanners typically failed to see is that safe and lively urban life is largelythe unplanned outcome of informal contact in public spaces. Jacobs argued thatunder the right conditions large numbers of people will choose to use publicspaces—e.g. sidewalks and plazas—throughout the day and night, providing “eyeson the street” that informally monitor and constrain bad behavior.
Safe,interesting public spaces attract people, who in turn attract even more people,making the spaces more interesting, and so on.