Skip to content
Against Certainty
Notes on probability, panic & better guesses

File 00 — the thesis

The goal is certainty.⌃ better uncertainty.

A field guide for thinking when you don't know — and acting anyway. Hold a belief as strongly as the evidence allows. No stronger.

start with a scenario →or take the whole route below

Start here.

Three steps, about ten minutes. Everything else on this site is optional.

01Feel the mistakeGuess your way through a scenario60 seconds →02Do it with your ownConvert a panic you're actually havingthe tool →03Then find out why it worksYour Brain Hates Base Rates5 min →

The problem

We are bad at uncertainty.

We mistake feeling for evidence, overweight a single signal, ignore base rates, and treat panic like intuition. Every one of these is a sentence the brain writes too fast — and then has to cross out.

The method

Four moves before you panic.

Not a mantra. A correction routine. Run it the next time a single data point tries to write your whole story.

the full field guide →
  1. 01

    Name the belief

    What do I actually think is true right now? Say it in one sentence.

  2. 02

    Check the base rate

    How often does this kind of thing happen anyway, before I look at today?

  3. 03

    Weigh the evidence

    Is this a strong signal, or just loud noise that feels like one?

  4. 04

    Update, don't collapse

    Move your estimate. A little. Not all the way to the worst case.

File 03 — the one tool that matters

The Panic-to-Probability Converter.

Name the fear. Answer four questions about your prior, your sample size, and whether anything actually changed. It crosses out the catastrophe and writes in a calmer reading of the evidence.

convert a panic →

Specimen

My app is dead.

⌃mostly a loud feeling on thin evidence.

weak signal
how much you should conclude8–66%

Things you can break.

Small instruments that make one idea obvious by letting you push it around. Drag the sliders.

all 22 tools →

Four things to get better at.

Every essay, scenario and tool is filed under one of these.

  • 01ProbabilityBase rates, Bayes, expected value, regression to the mean. The math your gut skips.
  • 02PanicCatastrophising, negativity bias, emotional evidence. Why a strong feeling is not a strong proof.
  • 03JudgmentDecisions under uncertainty. One bad day is not a trend. Small data drives you mad.
  • 04BeliefsUpdating, confirmation bias, motivated reasoning. Keep your convictions on a short leash.

Longer arguments.

One idea each, held loosely.

all 15 essays →