In 1999 “Pace Layers” made its debut in the book The Clock of Long Now by Stewart Brand. It appeared as a deceptively simple diagram with the caption: "The order of civilization. The fast layers innovate; the slow layers stabilize. The whole combines learning with continuity."
The six Pace Layer levels in descending order from the highest & fastest to the lowest & slowest are Fashion, Commerce, Infrastructure, Governance, Culture, Nature. Stewart’s initial point was to give insight into how a healthy society works. But fifteen years later, this idea about interacting layers that change at different speeds has been useful in ways he never expected.
Prominent designers and tech company executives have cited the Clock book and Pace Layers and told how it has changed their thinking. Many others have applied the idea to their work in design, management, engineering, and numerous other areas.
“This is a data free document,” Stewart quipped in response to an audience question about the Pace Layers illustration. That may reveal one reason for its longevity. Proposed initially as a way to view society, it has survived as a framework. It’s not tied to “facts” which may turn out to have expiration dates. Pace Layers travels well and ports easily to other systems.
"Quite a lot of people decided it was about software and systems and systems design," chuckled Stewart; he wasn't familiar with the term "full stack design" before learning that Pace Layers had been endorsed as a good metaphor for it.
Paul Saffo and a few others who use and teach Pace Layers spoke about what makes it a useful tool for analyzing our past, present and future. Paul, a founding Long Now board member and futurist, finds the concept invaluable for his own work, including teaching forecasting at Stanford.
Here’s how Stewart introduced the idea back in 1999:

I propose six significant levels of pace and size in the working structure of a robust and adaptable civilization. [...] In a healthy society each level is allowed to operate at its own pace, safely sustained by the slower levels below and kept invigorated by the livelier levels above.

Stewart has credited Freeman Dyson and Brian Eno, amongst others, for helping him form the concept. In this talk he went deeper into Pace Layers’ origins. "Like all good things this was stolen," he began, then paid tribute to architect Frank Duffy's concept of the nested “Shearing Layers” of a building. Stewart wrote about Duffy's work in his 1994 book How Buildings Learn: What Happens After They’re Built.
The presentation included an amazing artifact: a preliminary sketch of the Pace Layers diagram from December 1996, hand-drawn by Stewart after a talk with Brian Eno. That conversation helped finalize the idea: after Eno’s input he changed the top layer’s name to “Fashion” from “Art” and the layer labeled “Government” became “Governance.” If there are only six words, they have to be the right words.
Relationships between layers are key to the health of the system. More specifically, as both Stewart and Paul pointed out, conflicts caused by layers moving at different speeds actually keep things balanced and resilient. Paul called this “constructive turbulence.”
Innovation challenges orthodoxy. Wisdom repels destabilizing change, but also takes useful novelty onboard. Stewart, as much as anyone, has been an intellectual participant across some of our society’s most remarkable decades. As an agitator and as a bulwark. He has been the firebrand and now the grey beard. Pace Layers has proven itself low, slow, and here to stay. It’s fitting that the founder of the Whole Earth Catalog has given us access to a tool that’s so simple and enduringly useful.