Nearly all young men have a compass with which they delight in measuring the future. When their will is equal to the breadth of the angle at which they open it the world is theirs. But this phenomenon of the inner life takes place only at a certain age. That age, which for all men lies between twenty-two and twenty-eight, is the period of great thoughts, of fresh conceptions, because it is the age of immense desires. After that age, short as the seed-time, comes that of execution. There are, as it were, two youths,—the youth of belief, the youth of action; these are often commingled in men whom Nature has favored and who, like Caesar, like Newton, like Bonaparte, are the greatest among great men. I was measuring how long a time it might take a thought to develop. Compass in hand, standing on a rock some hundred fathoms above the ocean, the waves of which were breaking on the reef below, I surveyed my future, filling it with books as an engineer or builder traces on vacant ground a palace or a fort.