Importance of Conceptual Integrity in System Design

However, I really think that the immediate examples given by the author are actually not great examples of conceptual integrity, because the author too quickly conflates "conceptual integrity" with "consistency" (note the repeated use of "everything is a" in the examples given):

  Smalltalk ("everything is an object", and the small set of other accompanying principles)
  SQL ("all data is in tables", with keys and constraints)
  Lisp ("everything is a list")

I would even go as far to say that an over-emphasis on simplistic consistency speaks more to the lack of a genuine concept, or as the classic quote has it: "consistency is the last refuge of the unimaginative".

And committees love consistency because it's a cheap sell.

On the other hand, conceptual integrity just means staying true to the concept, however that is defined, so that conceptual integrity could well mean a break from simplistic consistency where the concept demands it.

If I can give it a shot, I would say that the human body is a better example of conceptual integrity in system design: not everything is a head or a hand, not everything is a foot or a finger, not all fingers are the same size, and yet everything works together. The conceptual integrity lies more in the overall symmetry of the human body, its purpose, its functions, its senses, motion, perception, thoughts, speech, actions, and especially in its interdependent relationship to others in community, as well as everything else in the world.

It's also talent that is hard to recognize and can be valued very differently from one organization to the next. I've been in the room with developers and management looking cross-eyed at me as I walk them through a top down business/problem decomposition and system design questioning the value of the entire exercise. Not surprising, these are organizations which have extremely brittle systems full of overlapping and "hard to reason about" abstractions.

(this is related imo to your post: https://brooker.co.za/blog/2020/10/19/big-changes.html - )

On a related tangent, I've been re-reading "The Open Hand - Essays on Le Corbusier". Specifically, the "Le Corbusier at Pessac - Professional and Client Responsibilities" essay by Brian Brace Taylor.

https://www.worldcat.org/title/open-hand-essays-on-le-corbus...

Pessac: https://www.archdaily.com/940878/le-corbusiers-cite-fruges-l...

That project basically failed its intended purpose. The client, M. Frugès, was apparently an enlightened capitalist, willing to invest in the vision of the young architect, even when incurring financial losses, because of Pessac. Corbu also learned, on the job, how to, and how not to, build his modernist vision. The whole thing was a fiasco on many levels. But it was a necessary project for progress in the field.

Which is the point: architectural innovation is costly and even great architects leave a trail of failed early projects. Yes, Corbu went on to master his field, and he did deliver (opinions of course vary) on the program of modern, afforadable, mass housing for the urban working class:

https://en.wikipedia.org/wiki/Unit%C3%A9_d%27habitation

But then:

"You know, it is life that is right and the architect who is wrong." - Le Corbusier (!)

https://libquotes.com/le-corbusier/quote/lbz6x3v

It's a problematic vocation (bricks or bytes). Love it or leave it.