Every mental model you trust is also a model of what you don't need to look at. That's not a flaw — that's exactly how models work. But Vātsyāyana, the 4th-century commentator on the Nyāya school's root texts, distinguished between two different cognitive acts that look identical from the outside: pakṣa, a proposition held open for testing, and siddhānta, a settled conclusion used as a foundation for further inference. The trouble he identified wasn't that people confuse these two — it's that siddhānta is invisible to the person holding it. You only experience it as 'how things obviously are.' The implications for anyone who works with mental models are uncomfortable: the more reliably a framework has served you, the more thoroughly it has erased the boundary between 'tested proposition' and 'background assumption.' The practical move Vātsyāyana recommends isn't doubt — it's deliberately re-exposing the conclusion to the conditions that would falsify it. Not 'is this model correct?' but 'what specific situation would prove it wrong, and have I recently been in that situation without noticing?'

Pick one framework you've used at least three times this week. What specific outcome would have to occur for you to retire it?

Drawing from Nyāya (Vātsyāyana's Nyāyabhāṣya commentary tradition) — Vātsyāyana (4th–5th century CE, Nyāyabhāṣya)