The intelligence can only be led by desire. For there to be desire, there must be pleasure and joy in the work. The intelligence only grows and bears fruit in joy. The joy of learning is as indispensable in study as breathing is in running.
Simone Weil, "Reflections on the Right Use of School Studies with a View to the Love of God," Waiting for God, Craufurd, tr. Harper & Row [New York: 1973] p. 110.