Clerestory

Revolutions, Step Changes, Paradigm Shifts

July 21, 2020

Part of a series on revolutions.

You say you want a revolution?
Well, you know
We all want to change the world
You tell me that it’s evolution
Well, you know
We all want to change the world

— The Beatles

This page will define terms. See also: Characteristics of Revolutions.

Defining complexity

When I write revolution, I mean a step change (increase) in complexity. Complexity — as in Complexity Theory — has no specific definition, but rather complex systems have a set of characteristics that often occur together. You can find a great introduction to the topic in this article or this video intro.

In complex systems, the characteristics I’m interested in are:

  • Systems consist of many constituent parts or nodes
  • Systems are layered on top of one another
  • Emergent behaviour at the system level
  • Self-organisation, limited top-down control
  • Feedback loops, vicious/virtuous cycles, non-linear dynamics
  • Dense interconnectivity
  • Benefit from diversity
  • Adaptivity/iteration/selection
  • Sensitivity to initial conditions, path dependence
  • Operate at the edge of chaos/criticality, close to phase transitions
  • Global disorder or unpredictability at the system level, but local order, and resilience/antifragility of the system as a whole
  • Relationships between nodes are more important than the nodes themselves

If there’s demand, I’ll write a separate page on complexity. Otherwise the above two links are a good introduction to these principles.

The particular aspect of complexity that I’m interested in is how and why complexity increases.

Defining revolutions

So what are revolutions? I gave a fairly random list in the introduction to this series. Here I’ll try to give more specific examples of how levels of complexity interact and increase. Ultimately I will give a list of characteristics, as others have done for complexity (above).

  • Physics: A molecule is a group of two or more atoms held together by chemical bonds. The molecule is more complex than any of its constituent atoms. Atoms have a similar relationship to subatomic particles. And in the other direction, molecules can be combined to make all sorts of interesting things (e.g., you).
  • Biology: Organisms were once entirely unicellular. Eventually certain organisms became multicellular.
  • Human organisation: At some point, humans probably had group sizes of a few dozen like other primates. This increased, maybe to 150. Then it increased again, into city-states. Eventually it increased again to nations, and now we may or may not be on our way to something else.
  • Language: Presumably before we had grammar, we had single words to refer to things. Eventually these were combined into sentences. Sentences were later combined into oral traditions, and then into longer texts.

Already some trivial patterns are obvious. The simpler elements must come before the more complex ones. Atoms predate molecules, unicellular organisms predate multicellular ones, humans predate states, words predate books.

Furthermore, it is apparent that the more complex elements combine the simpler elements. These combinations have emergent properties, which cannot be ascribed to or explained by the parts that comprise them. They emerge at a higher level of organisation.

A simple example would be that of water. Water has properties, like being a liquid at room temperature, or wetness, that neither its constituent hydrogen nor oxygen alone has. Or think of a company or nation, which can take actions or have attributes that are not really shared by all (or even any) of its individual constituents.

What I’m calling a revolution is the point at which complexity increases, often leading to an explosion of diversity at a newly emergent level. In physics, this would be the formation of atoms from particles, or molecules from atoms. In biology, this would be the development of multicellular organisms. In human organisation, this would be the development of city-states, or nation-states. In language, this would be the first oral traditions, or the writing of longer texts (or much later, the printing press).

These are just examples. They are hopefully illustrative both because of their simplicity and because they show how broadly I’m intending to sweep across domains.

I’m also going to discuss fertile periods for development and change that precede or follow revolutions. For example, periods of experimentation, Golden Ages, periods of political upheaval, and so on. The connection between these periods and revolutions should become clearer in later posts.

Step changes

Often these increases in complexity look like “step changes,” and I may occasionally use that phrase.

The term step change is of recent origin. Wiktionary says that the concept has been borrowed from mathematics and technology, from step function. For that term Wiktionary gives a rather boring description about how the function actually works.

The OED improves this: “a function that increases or decreases abruptly from one constant value to another.” The abruptness is key, as is the notion of ascending the stairs. It is not that the ascent cannot be stopped or sometimes even reversed; but when ascending the tendency is not to turn back. More on when complexity decreases later.

The key thing here is that reaching a new step or level opens up a new playing field.

Revolutions and Paradigm shifts

Kant was the first to use the phrase “revolution in thinking” (Revolution der Denkart) in the Critique of Pure Reason (1787). I will use it in that sense, and not just political revolutions specifically. But I will also be using it for cultural developments that are less obviously ways of thinking. For example, you could view the development of language, or the development of monotheism as revolutionary events, but they are not typically thought of as revolutions in Kant’s sense.

Kuhn’s The Structure of Scientific Revolutions is incredibly insightful when it comes to the evolution of ideas. He refers to scientific revolutions (Newton, Copernicus, etc) to describe times when a scientific paradigm shift occurs. You can see more about his schema here. His revolutions, like Kant’s, are narrower in scope than the ones I’m discussing, as they mainly relate to a scientific understanding of the world.

For me, a revolution is when, in any domain, complexity increases, opening a new field up for diversity. A canonical example would be the Cambrian Explosion, when complex multicellular organisms really took off, including pretty odd things like a five-eyed arthropod.


I'm Bryan Kam. I'm thinking about complexity and selfhood. Please sign up to my newsletter or see more here.