Systems & complexity

12 ideas across the corpus

Why the whole behaves unlike its parts — feedback, bottlenecks, emergence and collapse.

Complex systems break the intuition that causes are near their effects. Systems thinking traces the loops; emergence explains how simple rules produce ant colonies and cities; a single bottleneck governs the throughput of the whole; entropy quietly pulls everything toward disorder. This is how to reason about things too tangled to reason about linearly.

Key ideas here: Systems thinking, Emergence, Entropy, Bottleneck, Critical mass — and 7 more below.

Mental models

Mental model

Systems thinking

Systems thinking is understanding something by how its parts interact as a whole — through feedback loops, delays, and relationships — rather than…

Mental model

Emergence

Emergence is when a system exhibits properties or behaviours that its individual parts do not have on their own. The whole becomes qualitatively…

Mental model

Entropy

Entropy is a measure of disorder, and physics says it always increases in a closed system. As a mental model, it captures the universal tendency for…

Mental model

Bottleneck

A bottleneck is the single constraint that limits the output of an entire system — the narrowest point through which everything must pass. The theory…

Mental model

Critical mass

Critical mass is the threshold at which a system becomes self-sustaining — the point where enough has accumulated for a process to keep going on its…

Mental model

Path dependence

Path dependence is when the outcomes available today are constrained by the sequence of decisions and events that came before — history matters, and…

Mental model

Network effects

A network effect is when a product or service becomes more valuable as more people use it. Each new user adds value for existing users — so growth…

Mental model

Flywheel

A flywheel is a self-reinforcing loop where each part feeds the next, so momentum builds over time. Jim Collins’ metaphor: early pushes are hard and…

Mental model

Gall’s law

Gall’s law holds that a complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from…

Mental model