What is evolution log?

Evolution log is a concept in personal epistemology: Keep a record of how your major schemas have changed over time. Without a written log, you cannot distinguish genuine intellectual growth from retroactive rationalization. The evolution log is the infrastructure that makes belief revision visible, traceable, and honest.

Example: A product manager believes for three years that "users want more features." After a failed launch, she shifts to "users want fewer, better features." Without a log, she rewrites her past: "I always knew simplicity mattered." With one, she can trace the exact meeting, the exact user research session, and the exact data that forced the revision. She can see what she believed before, why she believed it, what changed, and what evidence drove the change. The log does not just record the new belief. It preserves the old one — and the distance between them is where learning actually lives.

This concept is part of Phase 16 (Schema Evolution) in the How to Think curriculum, which builds the epistemic infrastructure for schema evolution.