A mental model is not just a belief you hold — it is also a belief that holds you in place. The 19th-century American pragmatist Charles Sanders Peirce noticed something his contemporaries missed: inquiry doesn't begin when we're curious; it begins when we're uncomfortable. We only question a model when it starts producing friction with experience. Until then, it functions like infrastructure — invisible, load-bearing, and unexamined. Peirce called this 'the fixation of belief,' and he was deliberately provocative about it: most of us don't reason our way to our mental models, we reason from them, defending them with exactly the tools the model itself provides. The practical implication is this — if a model feels airtight, that's not evidence of its accuracy. It's evidence that it controls what counts as evidence. The one move that breaks the loop is to ask not 'does this fit my model?' but 'what kind of experience would have to happen before I'd abandon it?' If you can't answer that, you're not holding a mental model. It's holding you.

For one mental model you'd call central to how you operate — what specific experience would actually be enough to make you drop it?

Drawing from American Pragmatism — Charles Sanders Peirce