Unresolved Forces - Copyright Richard Fabian 2024

Generative, not descriptive

In the whole body of Christopher Alexander’s work, the slide towards generative processes is gradual but unmistakable. In The Nature of Order, Book 2[NoO2-02], the generative process takes centre stage, binding to the core argument from the first book with great strength. However, even in his early works, his theories seem based on an epiphany over the difference between traditional methods and those of modern architecture.

The architectural theories at the time were descriptive, not prescriptive[Grabow83]. There were very few rules on how to design a building. Mostly, they were rules on how to review a building once constructed. Buildings tended to be similar to those around them out of actively planned consistency rather than because they followed a generative process. The prescriptive rules were all in the domain of engineering. Only the engineers had rules for weights, ratios, and material limits to drive their decisions on what and how to build.

At the beginning of his work, Christopher Alexander suspected this was the cause of the problems in modern architecture; hence, he looked to traditional building processes to find a way to extract this generative nature. However, it would seem Peter Eisenman found the descriptive architecture thesis quite alarming. Eisenman became an internationally acclaimed architect later in life, known for projects such as the Memorial to the Murdered Jews of Europe and the Wexner Center for the Arts. His style is most certainly what one would call modern architecture.

Eisenman countered Christopher Alexander’s work with his theory of modern architecture[Formal63] in 1963, even before Notes on the Synthesis of Form[Notes64] was officially released. When understood, Eisenman’s thesis pushes back against Christopher Alexander’s unspoken complaint that modern architecture was not a generative process and thus was devoid of humanity.

However, even though Eisenman’s thesis argues against Alexander’s implicit conclusion, making it clear Eisenman holds that modern architecture is, in fact, a prescriptive and generative process, it does not quite hit the nail squarely on the head. He side-steps the question of humanity completely, preferring to generate forms with which to achieve artistic meaning, or even no meaning at all.

You can see evidence of Eisenman’s values in his later works. There are often clear signs of a desire to design for the sake of the piece’s meaning. Meaning drives form over value to the people who would use or inhabit his buildings. I see parallels with the architect Corbusier, with his artistically advanced but practically unsound Villa Savoye and the thankfully unrealised Ville Radieuse (Radiant City). Eisenman’s split bedroom¹ in House VI is one example of thrusting his intent onto the inhabitants of the building. Another issue with that house is the strange staircase lacking any handrail. As someone who enjoys good design, the quote by Dieter Rams (the famous designer of many Braun products) comes to mind:

Indifference towards people and the reality in which they live is actually the one and only cardinal sin in design

— Dieter Rams²

The problem behind both (Alexander’s and Eisenman’s) arguments is not whether modern architecture was generative but, more critically, what was generating it. This is an important distinction we will go into later. For now, we can take it that both aspects were true. Architects acted as Christopher Alexander proclaimed, actively designing without using a generative process tuned for human values. But Peter Eisenman’s thesis was valid in claiming modern architecture used a generative process.

What interests us is how we ended up with descriptive, not generative, software design patterns. They often describe what was achieved, not how to decide what to do or how to get there. When you want to implement a sorting algorithm, you use the instructions for implementing a specific one. That’s a description of an existing solution; a solution you take and apply to your language. A generative process wouldn’t have a particular solution in mind but would give you the steps to reach a valid resolution of your situation. It would have metrics or rules to verify the solution should hold under routine use.

If someone explains how to write a run-length encoder, that would be a descriptive pattern. It describes a solution you can use in quite a few cases but not how to invent a compression algorithm. But if someone explains information theory to you with examples, showing you how to look for the deeper information in your data and deciding how to encode it, that’s a generative process.

It’s worth noting that science is predominantly generative. The rules of physics, as they are known, allow you to figure out what to do when you try to produce a result. Imagine electrical circuits built by chance and hoping they will work out. Trying to mix chemicals to create new ones without the generative theory behind it is called alchemy, not chemistry. But art forms, too, can have generative rules. The layout of a good photo is reasonably well-known. Colour theory helps direct fine art. Understanding the effect of lighting on a scene improves clarity and can be used to evoke a mood, transferring emotions.

When art forms provide the rules of creation and let you work within them to forge something of value, you are freed by the constraints to concentrate on what you need to do to express yourself fully. This truism appears to have gone unnoticed by the architects who fought against Christopher Alexander’s work.

Patterns were meant to be a set of rules or guidelines on what to think about and when. They were to be used, in sequence, by people when constructing their homes and businesses to generate a good feeling and wholesome building. Patterns were intended to be generative. They are the rules or fabric of construction. They are the material with which we collaborate.

The artist, architect, or director is still the creator when they abide by well-understood patterns. Information, and therefore art and meaning, is the perceptible deviation from expectation. It’s an inspired choice or arrangement of already accepted structures. It’s not the presence of wacky elements (which Alexander called ‘Funky’ design[NoO2-02]) or taking things away without reason (which creates tension by their absence), but the meaningful expression through appropriate selection.

We should follow the patterns chosen by one in the know. Design patterns endow more to those who recognise new ones or see their essence. Those who can perceive new patterns from the random interaction of those building or creating we call the creators of new rules and a new, larger, more powerful language. They didn’t create, though, they saw. They had the acute vision to recognise something coming alive.

Generative processes are extremely important when creating anything of sufficient size. Without patterns, it leads to decision-making from a distance. This is sterile, wasteful, and ultimately alienating to those involved in the construction. Christopher Alexander himself said this from a different perspective:

ALL the well ordered complex systems we know in the world, all those anyway that we view as highly successful, are GENERATED structures, not fabricated structures.

— Christopher Alexander, The Nature of Order, Book 2[NoO2-02], p. 180.

Not just large but all successful, complex, well-ordered systems must be generated. A successful complex system in systems theory is found to only exist if grown from a smaller successful complex system. Success is never all at once. If we build a large complex system in one go, it will invariably fail to do what the designer intended. It will do something, and it might be hard to stop it. Just like a wish from a genie, it will do what you asked, not what you meant. So, we should never create large complex systems wholesale. Always build them out of smaller, successful systems. We must allow the smaller systems to combine and generate their way into larger systems.