Every product manager eventually faces a room where the data points one way and their gut points another — and freezes. The 18th-century Scottish philosopher Thomas Reid noticed something modern product culture keeps relearning: we don't actually reason our way to action from first principles. We act from what he called 'common sense' — not folk wisdom, but a bedrock layer of practical commitments that must be trusted before any deliberation can even begin. Without them, inquiry collapses into infinite regress. Reid's insight, fused with what cognitive scientist Gary Klein later documented in naturalistic decision-making research — where expert practitioners in high-stakes fields make fast, reliable calls not by comparing options but by recognizing situational patterns — suggests that the PM who agonizes longest over every decision may not be the most rigorous. They may be the one who hasn't yet developed a stable enough set of commitments to know what they're optimizing for. The cure isn't more frameworks. It's accumulated, honest exposure to consequences — shipping things, watching them land, and resisting the urge to explain away the results.

What did you actually ship or decide in the last quarter that you'd now call a mistake — and what did you tell yourself about why it happened?

Drawing from Scottish Common Sense Philosophy synthesized with Naturalistic Decision Theory — Thomas Reid (Essays on the Intellectual Powers of Man, 1786) synthesized with Gary Klein (Sources of Power, 1998)