ACityIsNotATree (ThoughtStorms)

Context : OnCities

ChristopherAlexander's paper (http://www.rudi.net/node/317 ) which argues that cities shouldn't be thought of as trees (ie. hierarchies) but as semi-lattices (ie. higher level modules can contain overlapping elements, without all elements in one high-level module also being elements of the other.)

Alexander then suggests that hierarchical thinking is hard for designers and planners to avoid because of a human psychological predispositions to use hierarchies or order and remember things. But, he argues, it's impossible to get a hierarchical decomposition that captures all the associations between elements, so attempting a hierarchical organization leads to the cutting of essential links in people's lives. His beautiful, furiously rhetorical last paragraph :

*For the human mind, the tree is the easiest vehicle for complex thoughts. But the city is not, cannot and must not be a tree. The city is a receptacle for life. If the receptacle severs the overlap of the strands of life within it, because it is a tree, it will be like a bowl full of razor blades on edge, ready to cut up whatever is entrusted to it. In such a receptacle life will be cut to pieces. If we make cities which are trees, they will cut our life within to pieces. *


Of course, it immediately suggests :


See also :