Here’s the test. Pick any strong opinion you hold. Now ask yourself: what would it take for me to change my mind about this? What evidence, what proof, what argument?
If you can answer that question clearly — if you can say “I’d change my mind if I saw X” — then you’re actually thinking. You’re reasoning. Your belief is based on something real that could, in theory, be disproven.
But if your honest answer is “nothing could change my mind” — or if you can’t even think of what would — then you’re not reasoning anymore. You’re just defending a belief. And there’s a huge difference.
This idea has a name: falsifiability. A belief is falsifiable if there’s some possible evidence that could prove it wrong. It doesn’t mean it IS wrong. It just means you’re open to being wrong if reality shows you something different. That’s the basic requirement for honest thinking.
The brain makes this really hard, though. Cognitive biases are baked into how we process information — we’re naturally wired to protect the beliefs we already have. When we encounter information that contradicts what we believe, we don’t neutrally evaluate it. We look for reasons to dismiss it. We tell ourselves the source is bad, the study is flawed, the person sharing it has an agenda.
As one researcher explained on NPR’s Hidden Brain, when we see data that doesn’t fit our beliefs, we try to distance ourselves from it — we say it’s not credible, reframe it, find a way to discard it. The new information never really gets a fair hearing.
And here’s the wild part: this happens even when the evidence is overwhelming. A striking example came from a science podcast on the anti-vaccination debate — a caller was asked directly how much evidence it would take to change her mind about vaccine safety. Her answer: no amount of scientific evidence could change her mind. None. That’s not a position that can be reasoned with, because it was never reached by reasoning in the first place.
This doesn’t make that woman uniquely broken or stupid. It just shows how deeply our brains can lock in a belief and then wall it off from challenge.
The fix isn’t to doubt everything or trust nothing. It’s just to stay honest with yourself. When you form an opinion, ask: what did I actually base this on? And what would it take for me to update it?
Strong thinkers change their minds when the evidence changes. That’s not weakness — that’s literally what thinking is for.
So next time you catch yourself in a debate where no argument ever seems to land on you, where every piece of counter-evidence somehow bounces off — pause. Ask yourself the test question. If there’s nothing in the universe that could shift your view, you might want to look harder at where that view actually came from.