Casuistry — the practice of reasoning through particular cases rather than applying universal rules — was the dominant method of moral decision-making in 16th-century Europe before it fell out of fashion and got a bad reputation. The Jesuit practitioners who developed it weren't relativists; they were insisting that a principle untested against a specific, messy case is not yet a principle — it's a preference. In finance, we do the opposite: we build general frameworks (mean reversion, margin of safety, position sizing rules) and then apply them uniformly, trusting the rule more than the case in front of us. But the Jesuit casuists would ask: what is the particular texture of this situation that your rule wasn't built to see? The framework became reliable through accumulated cases. It can also become blind through them. The discipline isn't abandoning your rules — it's periodically reading a specific position or decision from the ground up, as if the rule didn't exist yet, and checking whether the rule is illuminating the case or simply closing it.

Pick one financial rule you currently follow automatically. What specific case originally taught you that rule — and does this situation actually resemble it?

Drawing from Jesuit Casuistry / Early Modern Practical Ethics — Juan de Caramuel y Lobkowitz (Theologia Moralis Fundamentalis, 1652)