Adapted from a posting to the PatternsList, February 2, 1995...
Regarding patterns, ThomasGerth? asks if we should distinguish between the thing and it's description. I say yes. TheRepresentationIsNotTheRealThing We can make that distinction and probably a few more.
Let's call an artifact of design as built the PhysicalPattern?. Of course nothing in computer software is very physical but that doesn't bother me. More important is the act of drawing boundaries around some part of the total artifact and identifying it as something worthy of duplication.
ChristopherAlexander claims such recognition is a natural part of human behavior much like learning the grammar of a language by listening. I haven't a clue how the mind does this or how it stores the result. Still, let's call the result of such learning the MentalPattern. I once heard RalphJohnson exclaim "I have that pattern". The choice of words is telling. He was talking about something he held in his mental store.
Then there are descriptions of patterns. These Alexander calls the gate implying it is something we have to get through. A WrittenPattern (or DrawnPattern?) is our attempt to construct the gate. Our pictures and writing become more useful as they more closely approximate mental patterns. I find dredging around for patterns in my own mind to be difficult. I've been most successful when I get mad at some conversation that I consider wrong-headed. Then the patterns start to spill out. Actually, this is itself a clue about how the mind works.
So we have physical, mental, written and drawn patterns. When I say pattern I am talking about the mental pattern along with any of the other forms that happen to exist. That makes me a MentalFundamentalist?. I've met at least one PhysicalFundamentalist? who believes patterns can be mechanically identified by searching for duplications in programs. To him pattern would mean any duplicated structure and the mental, written or drawn representation that might also exist.
I think I agree with Ward, but I come at it from a different angle.
When I go to Giverny with a friend someday, I will look around and see the patterns in the gardens, and how the gardener used them to create the little worlds, the places therein, that are beautiful. These are beautiful to me partly because my mind is able to identify the places as cohesive places, places that serve the same purposes as other places that have given me pleasure earlier in life through their own fulfillment of purpose. This is a naturally human process. Prior experience lodges those patterns in my mind. And the places will be full of patterns that likewise draw on experience from my unconscious, or maybe even from my conscious. Those grand patterns may in turn comprise smaller places -- a bench, a fountain -- that evoke similar responses, through a similar process of memory.
The corporeal pattern is alive because of what happens with memory. Both the corporeal pattern and the pattern in my mind are "the pattern."
Each can exist without the other. Each can be alive without the other.
Monet captured some of these patterns in an impressionistic way reminiscent of Alexander's stipulation that sketches capture structure and not precision (Alberti's Law; see ArchitectsOnBlueprints). Is a great work by Monet also The Pattern? I think so. It does the same thing (and sometimes more) to my memory. It elicits the same reaction. It is alive because of what it does to memory.
If I tried to describe this setting in AlexanderianForm? as a WrittenPattern, is this also alive? does this also elicit the pattern? I think so. Alexander thinks so. It does the same thing (and sometimes more) to my memory. It elicits the same reaction. It is alive because of what it does to memory.
So there are three things: the patterns in our mind, the corporeal patterns in the physical world, and the written patterns in the world of literature and painting (we collectively call these "art").
Perhaps a koan: Is there a difference between matter that exists, and the description of the matter that exists? Do you believe in waves, or particles? Is the universe essentially particulate, or is it just energy? Or is it just models and descriptions whose reifications go beyond our limited understanding? I can't separate them (probably in a literal sense, to which Heisenberg might attest), so I don't.
-- JimCoplien
The above discussion started me thinking about this analogy: Patterns are to descriptions what impressionistic paintings are to realistic paintings (and photos).
Van Gogh's paintings represented the patterns that he saw. His Starry Night conveys more powerful information than any photo of the night sky could ever. His (over-)use of okra and yellow tones (perhaps due to a medical condition) emphasize qualities, of the things he painted, that we may not notice in a photograph or even through an actual first person viewing.
Art, because it is art, is a very subjective thing. So are patterns. Unlike descriptions (and most photos), they are very impressionistic -- they represent how we interpret the physical world.
Alexander's patterns (take Zen Windows for instance), like art, are very subjective. They can be argued about because they are impressions (greatly researched as they may be!), not descriptions.
-- ToddCoram