Every mental model you own was built for a world that no longer exists. This is the argument of Thomas Kuhn's lesser-read insight in The Structure of Scientific Revolutions — not the famous one about paradigm shifts overthrowing science, but the quieter observation that scientists routinely filter out anomalies to protect the models they already have. They're not being lazy. The filtering is automatic, a cognitive immune response. The same mechanism runs in you, daily. Your mental models about your health, your energy, your body's signals — they were calibrated at some earlier moment, under different conditions, and they now function as a kind of interpretive monopoly, deciding in advance what counts as data and what gets classified as noise. The Stoic concept of synkatathesis — the act of withholding assent before a judgment solidifies — was designed precisely for this gap, the moment between incoming signal and interpretation. Kuhn shows why that gap is so hard to keep open: the model wants to close it fast. The practical discipline isn't 'be more open-minded,' which is too vague to act on. It's narrower: treat the next anomalous signal your body sends — the unexpected fatigue, the surprising clarity — not as noise to explain away, but as a candidate falsifier of whatever model currently owns that territory.

Name one signal your body has been sending repeatedly that your current mental model has a ready explanation for. What would you have to give up to treat that explanation as provisional instead?

Drawing from Philosophy of Science (Kuhnian) synthesized with Stoic Epistemology (synkatathesis doctrine) — Thomas Kuhn (The Structure of Scientific Revolutions, 1962) synthesized with Stoic epistemology on synkatathesis as reconstructed in Sextus Empiricus