All successful men have agreed in one thing,—they were _causationists_. They believed that things went not by luck, but by law; that there was not a weak or a cracked link in the chain that joins the first and last of things. A belief in causality, or strict connection between every trifle and the principle of being, and, in consequence, belief in compensation, or, that nothing is got for nothing,—characterizes all valuable minds, and must control every effort that is made by an industrious one. The most valiant men are the best believers in the tension of the laws. "All the great captains," said Bonaparte, "have performed vast achievements by conforming with the rules of the art,—by adjusting efforts to obstacles." The key to the age may be this, or that, or the other, as the young orators describe;—the key to all ages is—Imbecility; imbecility in the vast majority of men, at all times, and, even in heroes, in all but certain eminent moments; victims of gravity, custom, and fear. This gives force to the strong,—that the multitude have no habit of self-reliance or original action. We must reckon success a constitutional trait. Courage,—the old physicians taught, (and their meaning holds, if their physiology is a little mythical,)—courage, or the degree of life, is as the degree of circulation of the blood in the arteries. "During passion, anger, fury, trials of strength, wrestling, fighting, a large amount of blood is collected in the arteries, the maintenance of bodily strength requiring it, and but little is sent into the veins. This condition is constant with intrepid persons." Where the arteries hold their blood, is courage and adventure possible. Where they pour it unrestrained into the veins, the spirit is low and feeble. For performance of great mark, it needs extraordinary health. If Eric is in robust health, and has slept well, and is at the top of his condition, and thirty years old, at his departure from Greenland, he will steer west, and his ships will reach Newfoundland. But take out Eric, and put in a stronger and bolder man,—Biorn, or Thorfin,—and the ships will, with just as much ease, sail six hundred, one thousand, fifteen hundred miles further, and reach Labrador and New England. There is no chance in results. With adults, as with children, one class enter cordially into the game, and whirl with the whirling world; the others have cold hands, and remain bystanders; or are only dragged in by the humor and vivacity of those who can carry a dead weight. The first wealth is health. Sickness is poor-spirited, and cannot serve any one: it must husband its resources to live. But health or fulness answers its own ends, and has to spare, runs over, and inundates the neighborhoods and creeks of other men’s necessities.