The mental and the moral, like the muscular, powers are improved only by being used. … He who lets the world … choose his plan of life for him has no need of any other faculty than the ape-like one of imitation. He who chooses his plan of life for himself … must use observation to see, reasoning and judgement to foresee, activity to gather materials for decision, discrimination to decide, and when he has decided, firmness and self-control to hold his deliberate decision.