Sunday, September 20, 2009

A Synthesis of Grammar and Life

In 1996, Christopher Alexander and I were sitting in his Berkeley kitchen, talking about "latent centers", those ripe places in the world from which certain things will naturally emerge. At some point, I said something like "well, latent centers are like non-terminals in a formal grammar ... ".

We'd been talking about creating computer tools that would guide people through generative sequences, that is, tools which would let people generate physical objects in a natural way, like the unfolding of a living organism. In that context, I said something like "... if latent centers are non-terminals, organic unfolding can be reasonably represented by a formal grammar: productions, terminals and non-terminals". In fact, a rather primitive form of this analogy was already famous: L-Systems or Lindenmayer re-writing systems ... which admittedly only make rather dead-looking approximations to organic forms.

I said something like "Chomsky intended these grammars to be generative, but we rarely use them this way in computing ... we use them for the recognition of artificial languages. Anyway, let's create a Sequence Description Language -- I can write a parser for it very quickly, using tools that were themselves inspired by his linguistic work ..."

Chris paused and said, pretty gravely, "That's not the right direction." I should say, this was in the context of creating an application, a design tool, intended to inspire people to create geometry with more life. In that context, I think he was right.

We only revisited the topic once, later in the year, sitting in a train in London, where I mentioned that the description languages of digital geography might be useful to us. Chris said something like "Yes, we should look into that. It might have the geometric depth we need." I remember thinking this was a way to pull Chris back into generative grammars, which, with the appropriate attribute passing, up and down, really can describe anything about natural geometry that humans can understand cognitively.

The difficulty that Alexander had with Chomsky reflected quite a deep history for him. In fact, A Pattern Language (APL) is named for, and clearly structured by, an analogy between generative grammar and the generation of living structure ... in APL, Alexander had already jumped to the analogy of the morphogenetic sequence, describing APL as a "base map". He spelled out a grammar-like use of APL to generate ontogenetic sequences as if they were sentences:

"... when we use the network of a language, we always use it as a sequence, going through the patterns, moving always from the larger patterns to the smaller, always from the ones which create structures, to the ones which embellish those structures, and then to those which embellish those embellishments ..."

Given this history, and the emerging synthesis regarding language and biology, what problem could Alexander possible have with Chomsky?

Well, for Alexander, the most important thing is an appreciation for the fullness and depth of life's geometry, and a devotion to understanding the richness of the real world.

We can describe a living thing logically, and yet, without the intervention of a person with artistic sensibilities, the resulting geometry from any automatic generation using this logical description is woefully and obviously incorrect. The "dead-like" appearance of L-systems, and consequently much Hollywood CGI, is evidence that grammar and automatic generation are simply not enough.

That's a fair critique: it takes people, or living organisms, to make a full, rich tapestry. And Christopher Alexander wants to know why. It clearly has something to do with geometry, with physics, with proportion, and with some fundamentally unknown thing. But Chomsky doesn't answer that question for Alexander. It took Alexander four large volumes of The Nature of Order to explain his current thinking on these qualities of life and feeling.

This is a bit unfair to both of them, but I'm going to quote from an interview with Christopher Alexander in Stephen Grabow's biography:

"Chomsky's work on generative grammar will soon be considered very limited ... it does not deal with the interesting structure of language because the real structure of language lies in the relationship between words -- the semantic connections. The semantic network -- which connects the word "fire" with "burn", "red" and "passion" -- is the real stuff of language. Chomsky makes no attempt to deal with that .. in that sense, pattern languages are not like generative grammars. What they are like is semantic structure, the really interesting part of language and which only a few people have begun to study ... is much more like the structure which connects patterns in a pattern language ... the real heart of language which has hardly been described yet."

So, to paraphrase Alexander: What is missing from the mathematics of analytic biolinguistics, is life.

Well, Chomsky is interested in life's richness ... in fact, most of his work has been aimed at thinking clearly about what we know about our own creative powers. And Chomsky's opinion is that we know "almost nothing", and that some of it may not be knowable, in the same way that we don't know where the forces of gravity, electro-magnetism, chemical attraction, or free will, actually come from. I'm sure these two would not disagree about that. And, obviously, we all share a desire to understand more about these fundamental mysteries.

In Chomsky's "Cartesian Linguistics", he emphasizes that Descartes sees human language as free from the control of stimulus, providing a faculty for the expression of thought. Language is not just a mechanical survival tool. From Descartes, Chomsky traces a thread through 18th century philosophy (most of which was lost until the late 20th century) that lands squarely on Christopher Alexander's doorstep -- quoting Goethe, Wilhelm von Humboldt, A.W. Schlegel and, below from 1818, S. T. Coleridge on natural form:

"The form is mechanic, when on any given material we impress a predetermined form, not necessarily arising out of the properties of the material ... the organic form, on the other hand, is innate; it shapes, as it develops, itself from within, and the fullness of its development is one and the same with the perfection of its outward form. Such as the life is, such is the form."

The paragraph above could be a summary of Christopher Alexander's The Nature of Order, published almost 200 years later.

Completely independently, The Nature of Order opens with a praise of Descartes, with a berating of the mis-interpretation of his work by subsequent generations:

"The mechanistic idea of order can be traced to Descartes, around 1640. His idea was: if you want to know how something works, you can find out by pretending that it is a machine. You completely isolate the thing you are interested in -- the rolling of a ball, the falling of an apple, the flowing of the blood in the human body -- from everything else, and you invent a mechanical model, a mental toy, which obeys certain rules, and which will then replicate the behavior of the thing. It was because of this kind of Cartesian thought that one was able to find out how things work in the modern sense."

"However, the crucial thing which Descartes understood very well, but which we most often forget, is that this process is only a
method. This business of isolating things, breaking them into fragments, and of making machinelike pictures (or models) of how things work, is not how reality actually is. It is a convenient mental exercise, something we do to reality, in order to understand it."

"Descartes himself clearly understood his procedure as a mental trick. He was a religious person who would have been horrified to find out that people in the 20th century began to think that reality
itself was actually like this. But in the years since Descartes lived, as his idea gathered momentum, and people found out that you really could understand how the bloodstream works, or how the stars are born, by seeing them as machines -- and after people had used the idea to find out almost everything mechanical about the world from the 17th to 20th centuries -- then, sometime in the 20th century, people shifted into a new mental state that began treating reality as if this mechanical picture really were the nature of things, as if everything really were a machine."

In other writings, Chomsky observed that educated people today typically think the mechanical model of the universe was laid to rest by Quantum Mechanics in the 20th century -- when, for working scientists, Newton had done this explicitly in the 18th Century. That said, clearly the new mechanistics Alexander alludes to, propagating the life-draining technocratic organization of society, is on the increase, something we should all be fighting against. Chomsky and Alexander are clearly in agreement about this.

So since, in my modeling of their opinions, I can find no remaining disagreement between them, I've embarked on the road Alexander and I did not take in 1996. The cognitively understood portions of the real world can be completely described by a generative grammar, and the emotionally understood portions can be described by the same when they are written by people -- especially with the addition of a notation for morphogenetic sequences, which describes gradients of emerging structures across a whole developing system.

I call this project "Blooming Logic" for obvious reasons. It's expressed first as an artificial language for expressing the human-driven process of "growing" a bit of engineering or software. The generator, and tool, I call "Grogix". I'm hoping that this can help us to tap nature's successful and coherent developmental methodology, and bring holistic thinking explicitly into computing.


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