Theories and Manifestoes of Contemporary Architecture

Theories and Manifestoes of Contemporary Architecture

Ed. Charles Jencks and Karl Kropf

AD Academy Editions, 1997

CHRISTOPHER ALEXANDER

A City is not a Tree

At a time o f increasing concern over the adequacy o f design method. A City is not a Tree' broke open and reoriented the debate. It a represented a fundamental change in ChristopherAlexander's (b / 9ü Vienna o f British parents) thinking. While retaining the mathematiü foundation underlying his Notes on the Synthesis of Form,'A City not a Tree' takes it in a very diüerent direction. Where the one see a crystalline logic to arrive at the notion of'fitness'between form ar programme, the other points to a fundamental ambiguity and ove lap in the relation of form to its uses. The one is an extreme exter sion o f Modernist rationalism, the other a reaction against it.

The tree of my title is not a green tree with leaves. It is the name for a pattern of thought. The semi-lattice is the name for another, more complex pattern of thought. In order to relate these abstract patterns to the nature of the city, I must first make a simple distinction. I want to call those cities which have arisen more or less spontaneously over many, many years natural cities. And I shall call those cities and parts of cities which have been deliberately created by designers and planners artificial cities. Siena, Liverpool, Kyoto, Manhattan are examples of natural cities. Levittown, Chandigarh, and the British New Towns are examples of artificial cities. . .

Too many designers today seem to be yearning for the physical characteristics of the past, instead of searching for the abstract ordering principle which the towns of the past happened to have, and which our modern conceptions of the city have not yet found.

What is the inner nature, the ordering principle, which distinguishes the artificial city from the natural city?

You will have guessed from my title what I believe this ordering principle to be. I believe that a natural city has the organization of a semi-lattice; but that when we organize a city artificially, we organize it as a tree.

Both the tree and the semi-lattice are ways of thinking about how a large collection of many small systems goes to make up a large complex system. More generally, they are both names for structures or sets. . .

The semi-lattice axiom goes like this: A collection of sets forms a semi-lattice if and only if, two overlapping sets belong to the collection, then the set of elements common to both also belongs to the collection. . .

The tree axiom states: A collection of sets forms a tree if and only if, for any two sets that belong to the collection, either one is wholly contained in the other, or else they are wholly disjoint. . .

Since this axiom excludes the possibility of overlapping sets, there is no way in which the semi-lattice axiom can be violated, so that every tree is a trivially simple semi-lattice.

However, in this paper we are not so much concerned with the fact that a tree happens to be a semi-lattice, but with the difference between trees and those more general semi-lattices which are not trees because they do contain overlapping units. .

It is not merely the overlap which makes the distinction between the two important. Still more important is the fact that the semi-lattice is potentially a much more complex and subtle structure than a tree. . .

Whenever we have a tree structure, it means that within this structure no piece of any unit is ever connected to other units, except through the medium of that unit as a whole.

The enormity of this restriction is difficult to grasp. It is a little as though the members of a family were not free to make friends outside the family, except when the family as a whole made a friendship. .

When we think in terms of trees we are trading the humanity and richness of the living city for the conceptual simplicity which benefits only designers, planners, administrators and developers. Every time a piece of a city is torn out, and a tree made to replace the semi-lattice that was there before, the city takes a further step toward dissociation.

In any organized object, extreme comparümentalization and the dissociation of internal elements are the first signs of coming destruction. In a society, dissociation is anarchy. In a person, dissociation is the mark of schizophrenia and impending suicide. An ominous example of a city-wide dissociation is the separation of retired people from the rest of urban life, caused by the growth of desert cities for the old such as Sun City, Arizona. This separation is possible only under the influence of tree-like thought.

It not only takes from the young the company of those who have lived long,

but worse, causes the same rift inside each individual life. As you will pass into Sun City, and into old age, your ties with your own past will be unacknowledged, lost, and therefore broken. Your youth will no longer be alive and in your old age the two will be dissociated, your own life will be cut in two.

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.

Extracts. Source: Architectural Forum, vol I 22; no I, April I 965. (C) Christopher Alexander

1965

CHRISTIAN NORBERG-SCHULZ

lntentions in Architecture

Published within a few years ofAldo Rossi's Architecture of the City and Robert Venturi's Complexity and Contradiction, Christion Norberg Schulz` (b I 926) Intentions in Architecture is equally a reaction against Modernism` in particular as realised a fter the Wor. Norberg-Schulz begins the book with an extended argument suggesting that the per ception of form has a cultural basis and meaning in architecture is the result of cultural intentions. The task of the architect is then to work within the network of those intentions.

"We are here faced with basic problems which involve a revision of the aesthetic dimension of architecture. How can architecture again become a sensitive medium, able to register relevant variations in the building tasks, and at the same time maintain a certain visual order? A new aesthetic orientation transcendin the arbitrary play with forms is surely needed, although it is not claimed that the result should resemble the styles of the past. Undoubtedly we need a formal differentiation of the buildings corresponding to the functional differences of the building tasks. But so far we have not found any answer to the question of whether the differentiation should also acquire a symbolizing aspect b the assignment of particular forms to particular functions with the purpose of `representing' a cultural structure. So far modern architecture has had the character of a `belief' rather üan a worked-out method based on a clear analysis of functional, sociolo ical and cultural problems. . .

The Problem

What we need is a conscious clarification of our problems, that is, the definition of our building tasks and the means to their solution. . . What purpose has archience us? ^s aü human product?. . How does architecture (the environment) influTo give the questions about the purpose and effects of architecture a basis, it is necessary to inquire whether particular forms ought to be correlated with particular tas_kform ^..

We do not intend that the study of history should lead to a new historicism based on a copying of the forms of the past. The information given by history should above all illustrate the relations between problems and solution, and thus furnish an empirical basis for further work. If we take our way of putting the problem as a point of departure for an investigation of architecture's (changing) role in society, a new and rich field of study is laid open. . .

On a purely theoretical level we gain knowledge about the relation between task and solution. But this knowledge may also be incorporated into a method which helps us in solving concrete problems, and which might facilitate the historical analysis going from the solution back to the task. The historical analysis orders our experience and makes the judgement of solutions possible. All in all we arrive at a theory treating architectural problems. . . Architecture is explicitly a synthetic activity which has to adapt itself to the form of life as a whole. This adaptation does not request that every work should be related to the total whole. The individual work concretizes secondary wholes, but because it belongs to an architectural system, it participates in a complete concretization. New concretizations can neither imitate the past, nor break completely with tradition. They are dependent upon the existence of symbol-systems which are capable of development. This implies that we should conserve the structural principles of tradition rather than its motives. . .

The modern movement is the only true tradition of the present because it understands that historical continuity does not mean borrowed motives and ideals, but human values which have to be conquered in always new ways. . .

Modern forms have developed through experimentation and the fight against borrowed motives. But they have never been ordered, they have never become a real formal language. This is the basic problem that the present generation of modern architects has to face, and it can only be solved through the formation of types. The types must be interrelated in such a way that they form a hierarchy corresponding to the task-structure..."

Extracts. Source: Christian Norberg-Schulz, Intentions in Architecture, MIT Press (Cambridge, Mass), I977. (C) 1977 by The Massachusetts Institute ofTechnology First published in 1965 simultaneously in Oslo, Norway, for Scandinavian University Books by Universitetsforlaget, i  n the United Kingdom by George Allen & Unwin Ltd, London, and in the United States by The Massachusetts Institute ofTechnology, Cambridge, Mass.