The soul, like the body, acquires vigor by the exercise of all its faculties. In the midst of the world, in overcoming difficulties, in conquering selfishness, indolence, and fear--in all the occasions of duty, it employs, and reveals by employing, energies that render it efficient and robust--that broaden its scope, adjust its powers, and mature it with a rich experience.
Living Words (ed. 1861)