Critical Thinking Fundamentals

Working out whether a claim is actually supported, including the ones you'd like to be true.

Critical thinking is the habit of asking what would have to be true for a claim to hold, and then checking. Not cynicism, and not doubting everything equally — that's just as lazy as believing everything, and slower. The work is mostly unglamorous: noticing where a number came from, separating what was observed from what was inferred, and being hardest on the conclusions you find most congenial, because those are the ones nobody else will bother to challenge in front of you. Most bad workplace reasoning isn't a logical error anyone could name. It's a plausible story that nobody stopped to check the base of.

Scenarios

A vendor's benchmark shows their product is four times faster. What would you do — accept it as directionally right, or find out what the comparison was run against, on what hardware, and who chose the workload?

You're building the case for a decision you already believe in. What would you do — assemble the strongest supporting evidence, or spend the first hour looking specifically for the best argument against it?

Someone quotes a well-known industry statistic to close down a debate. What would you do — accept it as common knowledge, or ask where it comes from, given that "everyone knows it" is a claim about circulation rather than evidence?

Takeaway

Ask what the claim would predict if it were false. If the answer is "nothing different," it isn't doing any work.
Trace numbers to their source before repeating them. Every hop strips a qualifier.
Check what a metric actually measures, not just what it's called.
Apply your most demanding standard to conclusions you like. Nobody else will.
Separate "this argument is well constructed" from "this argument is correct." Fluency is a property of the speaker, not the world.