From Rebecca Konyndyk DeYoung, Glittering Vices, 9.
A few years later, reading Thomas Aquinas (1224-74) on the virtue of courage, I happened across a vice he called pusillanimity, which means “smallness of soul.” Those afflicted by this vice wrote Aquinas, shrink back from what God has called them to be. When faced with the effort and difficulty of stretching themselves to the great things of which they are capable, they cringe and say, “I can’t.”