Interesting post, luca. I find what you describe to be reminiscent of ideas I've encountered in the past, but perhaps expressed in different language.
One of these ideas that I find particularly intriguing is the concept of probability, and more specifically, randomness. I have to thank Nassim Taleb here, as it's through him that I've come to appreciate the beauty of randomness. I always like to think back to this example he provides in one of his books: how to forecast the total trajectory of billiard balls on a pool table. Given what we know about physics, it's very easy to forecast where the balls will go when there is only a cue and one other, provided we know things such as the speed and angle of impact, the drag created by the felt, the temperature, density of the balls, etc. But when you add each additional ball, the ability to predict trajectories increases exponentially, and randomness takes over.
I find this idea of urban emergence powerfully mirrors this example. Take enough "orderly pieces" and set them in motion on a table with some type of stimulus (be it an ideal location for a transportation hub or some kind of industry), and you get a complex system that is unpredictable in its detailed behavior but very predictable in its appearance as a whole. In other words, you don't know what type of neighborhoods will arise where and when, but you do know there will be a cohesive city there.
I understand the fascination with this idea, but I find I cannot agree with your statement:
I think there is plenty organic in urban development. Of course it is all relative. It cannot be 100% organic - in my mind, it cannot be all natural and by random chance, because there are fundamental rules always in effect. As in the billiards example, you will never end up with a ball gravitating in air or becoming embedded within the felt or being shattered upon impact from the cue (given what we know about physics). Similarly, there are certain constants that will always hold within urban environments, yet every such environment shares distinct characteristics with all others because of shared needs and desires of all urban residents.There is very little that is purely organic in the images above, they too stem from regulations and planning as much as by individual action.
A final example is the question of life itself: if you believe, as I do, in scientific evolution, you have to come to terms with the idea that we (and other advanced, very complex forms of life) evolved from a very simple blueprint. And that in the end, we are all made up of the same elements and function according to fundamental laws of science. Nonetheless, there is seemingly endless diversity in our expression of life.
Organic and random, yet inorganic and orderly. A harmonious dichotomy.