Scarcity changes the taste of things. Medieval Jewish philosopher Bahya ibn Paquda, writing in 11th-century Andalusia, built his entire ethics around what he called 'heshbon ha-nefesh' — an accounting of the soul — which required not just introspection but a precise reckoning with finitude: you cannot know how to spend something until you have honestly faced how little of it remains. What's striking is that modern research by psychologist Laura Carstensen reaches the same territory from a completely different direction. Her 'socioemotional selectivity theory' shows that when people perceive their time as genuinely limited — not abstractly, but concretely felt — their priorities spontaneously reorganize. They stop tolerating the peripheral. The insight these two traditions converge on is not that scarcity motivates you; it's that perceived time-horizon is a *filter*. It changes what even registers as worth doing. Most of us move through Thursday with an implicit assumption of open-ended time ahead, which means we apply no filter at all. The exercise Bahya would recognize: not 'what should I do?' but 'if this week were the last one of its kind, would this afternoon's agenda survive the audit?'

If you audited the last three Thursdays the way a careful accountant reviews ledgers — looking for waste, not to feel guilty but to see clearly — what would appear in the expense column that you've been treating as necessary?

Drawing from Medieval Jewish ethics combined with lifespan developmental psychology — Bahya ibn Paquda ('Ḥovot ha-Levavot / Duties of the Heart', c. 1080 CE) and Laura Carstensen (Socioemotional Selectivity Theory, Stanford Center on Longevity)