Hello TOC

Thinking Clearly · Lesson 4 of 6

Three habits of clear thinking

Slow down, try to prove yourself wrong, and reason from rules to cases. Test your instincts on the 2-4-6 rule and the nine-dots puzzle, and learn to spot the boundary an assumption draws around your thinking.

16 min · Not completed yet

Habit 1: make it slow

The first defence against System 1’s shortcuts is simple: slow down and write it down. Writing forces System 2 to work. A thought in your head can be vague; a sentence on paper has to say something definite, and then you, or someone else, can check it.

The Thinking Process tools are, among other things, a structured way of slowing down: every claim is written as a sentence, every connection as an arrow, and every arrow can be questioned.

Habit 2: try to prove yourself wrong

Most of what we know comes from inductive thinking: we observe a pattern, form a theory, and confirm it with more observations. The danger is in the last step. Try it.

This is the trap of confirmation. Once we have a theory, we look for evidence that fits it, and every fit makes us more confident, even though a thousand confirmations can’t prove a theory, while one counter-example can disprove it.

The falsification approach turns this around: after forming a hypothesis, look for evidence that would prove it wrong. It feels unnatural, because we are built to look for confirmation. In management it sounds like:

  • “If this really is the cause, what else should we see? Do we see it?”
  • “Where would this solution fail?”
  • “Who disagrees, and what do they know that I don’t?”

Habit 3: reason from rules to cases

Deductive reasoning starts from a general rule and applies it to a specific case:

  • All men are mortal (a general rule).
  • Jon is a man (a case).
  • So Jon is mortal (a conclusion).

In everyday work it takes the form “if this, then that should happen, because…”. Deduction lets us predict, and a prediction can be tested. That is why the Thinking Process writes cause and effect as “if… then…” statements: each one is a small deduction that can be checked against reality.

The boundaries we draw

What stopped most people? Nothing in the instructions said the lines must stay inside the square. We drew that boundary ourselves, without noticing, and then searched hard inside it.

Assumptions put a boundary around our thinking. They are rarely stated, so we rarely challenge them. Consider:

In order to get the job I want, I must have degree XYZ, because…

Is that boundary valid? Are there people who got that job without the degree? What did they have instead? The answer to “because…” is the assumption, and once it is written down, it can be challenged.

Pause and think: a manager says, “In order to meet customer due dates, we must keep every machine busy.” What would you ask?

  • “Which machines are the most expensive, and how many hours does each run per week?”
  • “How many shifts do you run?”
  • “Why? What connects busy machines to on-time delivery? Is that always so?”
  • “Who decided that?”

Ask for the “because”: the assumption behind the link. Once it is stated (“an idle machine is lost output”), you can test it. It is true at the constraint, but at other machines, busyness often just builds inventory and delays the orders that matter.

Slowing down, falsifying, deducing and surfacing assumptions are the habits. The Thinking Process turns them into tools you can use with a team.

Check your understanding

Answer all five. Get four right to complete the lesson.

1. Why does writing things down help?

  • It looks professional
  • It forces slow, deliberate thinking and makes claims checkable
  • It saves time
  • It replaces discussion, so meetings can be shorter

A sentence on paper has to say something definite.

2. The falsification approach means…

  • Collecting as much confirming evidence as possible before deciding
  • Asking the most senior person
  • Avoiding hypotheses
  • Looking for evidence that would prove your hypothesis wrong

One counter-example can disprove a theory; a thousand confirmations can’t prove it.

3. “If this, then that should happen, because…” is the form of…

  • Deductive reasoning
  • Inductive thinking
  • Social proof
  • Anchoring

From a general rule to a specific, testable prediction.

4. What stops most people solving the nine-dots puzzle?

  • It’s impossible
  • Not enough lines allowed for a solution inside the square
  • An unstated assumption that the lines must stay inside the square
  • Bad drawing skills

Assumptions draw a boundary around our thinking.

5. In “In order to X, I must Y, because Z”, what is Z?

  • The goal that the action is meant to serve
  • The assumption behind the link, which can be challenged
  • The solution
  • The problem

Write it down, then ask: is it really so? Always?