Your Brain: The Missing Manual

Critical Thinking

So far, your exploration into reasoning and the brain has been more than a little depressing. With its impressive catalog of logical errors, leaky assumptions, and glaring omissions, it's a wonder you're able to make toast without a textbook at hand.

Fortunately, you can train your brain to behave more rationally. The following sections present some of the best practices of critical thinking, which provides a disciplined way to challenge common sense.

Accepting Uncertainty

As you've already seen, your brain has a deep hunger for certainty. It's most comfortable with concrete, actionable information, and it barely tolerates ambiguity. Rather than use logic to openly investigate an issue, your brain prefers to latch onto a conclusion instinctively and use logic after the fact to defend it. The colorful writer Edward de Bono describes it this way: "The natural tendency of thinking is to support a view arrived at by other means."

To battle this tendency, you need to master the art of suspending judgment. The longer the interval between the time a question is posed and the time your brain locks into an answer, the more objective you'll be. Once your brain forms an expectation, that expectation acts like a magnet, pulling all your thinking and reasoning in one direction.

In some cases, you'll need to accept the ambiguity of having no clear answer at all. To do so, you need to fight against your brain's instincts, which favor bad explanations to no explanation. This tendency ...