Why do the 15 properties occur in nature?

In effect, [the fifteen properties] appear throughout nature — apparently because of the normal evolution of systems.

Virtually always, the specific structure of centers in a given case can be explained as a result of forces and processes which are mechanical in the conventional sense. […] However, such mechanical explanations do not explain why the properties themselves keep showing up.

The properties appear over a wide range of scales. They certainly appear at the scale of “everyday” (that is, at the scale of our own human bodies). They also appear equally at microscopic and subatomic scales, and at astronomical and cosmological scales. In short, these geometric properties occur commonly, throughout nature, at all scales. Yet, in spite of that, […] it is not usually possible to give a general explanation, or general theory, which explains why a particular property occurs pervasively as a repeating feature of the natural world.

If we compare the (mechanical/physical) reasons for a given property in specific cases, the reasons appear all very different. Yet, on a very abstract level, they cause a similar or even the same effect.

One wonders, then, if there might be a more general language for talking about function than the one we are used to — a language which talks only about the most fundamental connections and relations between systems and is based on centers. In such a language, the properties might be explained, reasonably, as the structural complements to the formation of stable and semistable systems. […] The fifteen properties are the ways in which centers can sustain each other’s coherence, so this might apply equally to those functional wholes in nature which appear within any stable or semistable system. They would then be the fifteen major ways in which “sustaining” between sub-wholes of a system does actually take place.

The properties seem to be patterns of general principles that contribute in some way to the stability and coherence of natural systems, maintaining their integrity and viability. Overall, the appearance of these properties is linked to the stability and robustness of the world.

Of course, none of these possible arguments explain why natural processes tend to create stable systems in the world. […] But I do observe, for the present, that, for whatever reason, boundaries contribute to the stability and coherence of natural systems. For similar system-reasons — so my argument goes — the other fourteen properties, too, will tend to appear in almost any natural system which is functionally stable or semistable, contributing in some way to its coherence and stability. Each of the fifteen properties does something of a characteristic nature to maintain the integrity and viability of natural systems. The appearance of these properties is linked to the stability and robustness of the world. That is because these properties represent the most fundamental ways in which space can be molded to form character, to create form, to form unique structure that is capable of having properties, behavior, and interesting or useful interactions with other structures.

All this that we recognize as the normal stable character of nature comes from its robustness — from an evolving morphology which works.

After reading this, I think Alan Kay with his hunch to design programming systems inspired by biology, with Smalltalk as an example, are a much more important idea that I already believed! Though I’m not sure how clearly Alan Kay saw the more abstract or general notion Alexander expresses here, and perhaps he was just struck by the beauty and efficacy of rather specific biological systems, the general path to think in coherent systems with much higher agency than what we usually build in software, could help some of these properties to emerge naturally.

Perhaps, the question is, “What is the minimal amount of machinery, or rules, or operations, needed to enable the creation of structure and behavior and interaction that is capable of generating the fifteen properties as emergent effects? I realize the irony that this sounds like a rather mechanical-rationalist question, but I’m currently not capable of expressing it better.

-> The concept of living structure

#book/The Nature of Order/1 The Phenomenon of Life/6 The fifteen properties in nature#