Descartes wasn't simply saying that intelligence requires effort—he was drawing a sharp line between *capacity* and *character*. A brilliant mind sitting idle, or worse, applied toward petty ends, counts for nothing; what matters is the deliberate discipline of directing that mind toward truth. We see this distinction everywhere in modern life: the gifted student who never finishes anything, the talented executive who uses sharp thinking to deceive rather than build, the restless reader who gathers knowledge but never acts on it. Descartes insists that virtue lies not in what we're born with, but in the daily choices we make about where we point our attention.