“Whoever in his public services is handcuffed and shackled by the vice of consistency will be a man not free to act as various questions come before him from time to time; he will be a statesman locked in a prison house, keys to which are in the keeping of days and events that are dead. Let me quote Emerson: 'A foolish consistency is the hobgoblin of little minds, adored by little statesmen.'”