Write belief updates as 'Based on [evidence], I am updating from [old] to [new]' — revision is calibration

Why This Is a Rule

Belief revision is psychologically costly. Changing your mind feels like admitting you were wrong — a threat to competence identity. This emotional cost causes people to resist updating even when evidence is clear, producing the "backfire effect" where disconfirming evidence strengthens rather than weakens the held belief.

The explicit update statement reframes revision from defeat to calibration. "Based on [evidence], I am updating my model from [old] to [new]" borrows the language of Bayesian updating — a rational, systematic process where revision is a feature, not a failure. The format externalizes the update, making it inspectable and trackable rather than emotionally charged and hidden.

The written artifact also creates accountability: you can review past updates to see whether your model improved over time (calibration is working) or whether you keep updating back and forth on the same topic (you're oscillating rather than converging — see If a belief flips three times without converging, you are reacting to noise).

When This Fires

• When evidence contradicts a belief you hold
• After a prediction fails and you need to update the model that produced it
• During any belief-revision moment where the instinct is to dismiss the evidence rather than update
• When reviewing past decisions reveals that a previously held model was wrong

Common Failure Mode

Updating silently — changing your behavior without explicitly revising the stated belief. You stop acting on the old model but never write the update, which means the old model persists in your documentation and in conversations with others. Explicit written updates ensure that the revision is reflected everywhere the old model appeared.

The Protocol

When evidence triggers belief revision: (1) Write: "Based on [specific evidence], I am updating my model from [old version: state what you previously believed] to [new version: state what you now believe]." (2) Note the specific change: what exactly is different between old and new? (3) Store the update with the original belief — not as a replacement but as a versioned revision, preserving the epistemic history. (4) The format makes revision feel like instrument calibration (systematic, competent) rather than defeat (embarrassing, threatening).