Theory Building

Code is not the deliverable. The theory the code embodies is the deliverable; the code is a lossy serialization of it. Peter Naur's argument in Programming as Theory Building is that a program's real content lives in the builders' mental model of how the world maps onto the code — and that when the model is lost, the surviving text degrades no matter how correct it was.

Naur's evidence for this is worth holding onto, because it is a finding rather than a metaphor. A team inheriting a compiler was given full documentation, annotated program texts, extensive written design discussion, and direct access to the original authors. They still proposed extensions that "effectively destroyed its power and simplicity," while the authors "were able to spot these cases instantly" and offered solutions framed entirely within the existing structure. The text was complete. The theory was not in it.