The war began with great fanfare and several victories, but it soon bogged down. A victory on one front would leave the Wu armies vulnerable on another. The king’s chief minister and adviser, Wu Tzu-hsiu, warned him that the barbarous state of Yueh, to the south, was beginning to notice the kingdom of Wu’s problems and had designs to invade. The king only laughed at such worries—one more big victory and the great Middle Kingdom would be his.

In the year 490, Wu Tzu-hsiu sent his son away to safety in the kingdom of Ch’i. In doing so he sent the king a signal that he disapproved of the war, and that he believed the king’s selfish ambition was leading Wu to ruin. The king, sensing betrayal, lashed out at his minister, accusing him of a lack of loyalty and, in a fit of anger, ordered him to kill himself. Wu Tzu-hsiu obeyed his king, but before he plunged the knife into his chest, he cried, “Tear out my eyes, oh King, and fix them on the gate of Wu, so that I may see the triumphant entry of Yueh.”

As Wu Tzu-hsiu had predicted, within a few years a Yueh army passed beneath the gate of Wu. As the barbarians surrounded the palace, the king remembered his minister’s last words—and felt the dead man’s disembodied eyes watching his disgrace. Unable to bear his shame, the king killed himself, “covering his face so that he would not have to meet the reproachful gaze of his minister in the next world.”

For the Chinese, the fate of the kingdom of Wu serves as an elemental lesson on what happens when you dissipate your forces on several fronts, losing sight of distant dangers for the sake of present gain. “If you are not in danger,” says Sun-tzu, “do not fight.” It is almost a physical law: What is bloated beyond its proportions inevitably collapses. The mind must not wander from goal to goal, or be distracted by success from its sense of purpose and proportion. What is concentrated, coherent, and connected to its past has power. What is dissipated, divided, and distended rots and falls to the ground. The bigger it bloats, the harder it falls.

First, Mayer Amschel allied himself with one family, the powerful princes of Thurn und Taxis. Instead of spreading his services out, he made himself these princes’ primary banker. Second, he entrusted none of his business to outsiders, using only his children and close relatives. The more unified and tight-knit the family, the more powerful it would become. Soon Mayer Amschel’s five sons were running the business. And when Mayer Amschel lay dying, in 1812, he refused to name a principal heir, instead setting up all of his sons to continue the family tradition, so that they would stay united and would resist the dangers of diffusion and of infiltration by outsiders.

Once Mayer Amschel’s sons controlled the family business, they decided that the key to wealth on a larger scale was to secure a foothold in the finances of Europe as a whole, rather than being tied to any one country or prince. Of the five brothers, Nathan had already opened up shop in London. In 1813 James moved to Paris. Amschel remained in Frankfurt, Salomon established himself in Vienna, and Karl, the youngest son, went to Naples. With each sphere of influence covered, they could tighten their hold on Europe’s financial markets.

This widespread network, of course, opened the Rothschilds to the very danger of which their father had warned them: diffusion, division, dissension. They avoided this danger, and established themselves as the most powerful force in European finance and politics, by once again resorting to the strategy of the ghetto—excluding outsiders, concentrating their forces. The Rothschilds established the fastest courier system in Europe, allowing them to get news of events before all their competitors. They held a virtual monopoly on information. And their internal communications and correspondence were written in Frankfurt Yiddish, and in a code that only the brothers could decipher. There was no point in stealing this information—no one could understand it. “Even the shewdest bankers cannot find their way through the Rothschild maze,” admitted a financier who had tried to infiltrate the clan.

In 1824 James Rothschild decided it was time to get married. This presented a problem for the Rothschilds, since it meant incorporating an outsider into the Rothschild clan, an outsider who could betray its secrets. James therefore decided to marry within the family, and chose the daughter of his brother Salomon. The brothers were ecstatic—this was the perfect solution to their marriage problems. James’s choice now became the family policy: Two years later, Nathan married off his daughter to Salomon’s son. In the years to come, the five brothers arranged eighteen matches among their children, sixteen of these being contracted between first cousins.

“We are like the mechanism of a watch: Each part is essential,” said brother Salomon. As in a watch, every part of the business moved in concert with every other, and the inner workings were invisible to the world, which only saw the movement of the hands. While other rich and powerful families suffered irrecoverable downturns during the tumultous first half of the nineteenth century, the tight-knit Rothschilds managed not only to preserve but to expand their unprecedented wealth.

No one represents this better than James Rothschild, the son who established himself in Paris. In his lifetime James witnessed the defeat of Napoleon, the restoration of the Bourbon monarchy, the bourgeois monarchy of Orleans, the return to a republic, and finally the enthronement of Napoleon III. French styles and fashions changed at a relentless pace during all this turmoil. Without appearing to be a relic of the past, James steered his family as if the ghetto lived on within them. He kept alive his clan’s inner cohesion and strength. Only through such an anchoring in the past was the family able to thrive amidst such chaos. Concentration was the foundation of the Rothschilds’ power, wealth, and stability.

The solution is a form of retreat inside ourselves, to the past, to more concentrated forms of thought and action. As Schopenhauer wrote, “Intellect is a magnitude of intensity, not a magnitude of extensity.” Napoleon knew the value of concentrating your forces at the enemy’s weakest spot— it was the secret of his success on the battlefield. But his willpower and his mind were equally modeled on this notion. Single-mindedness of purpose, total concentration on the goal, and the use of these qualities against people less focused, people in a state of distraction—such an arrow will find its mark every time and overwhelm the enemy.

Casanova attributed his success in life to his ability to concentrate on a single goal and push at it until it yielded. It was his ability to give himself over completely to the women he desired that made him so intensely seductive. For the weeks or months that one of these women lived in his orbit, he thought of no one else. When he was imprisoned in the treacherous “leads” of the doge’s palace in Venice, a prison from which no one had ever escaped, he concentrated his mind on the single goal of escape, day after day. A change of cells, which meant that months of digging had all been for naught, did not discourage him; he persisted and eventually escaped. “I have always believed,” he later wrote, “that when a man gets it into his head to do something, and when he exclusively occupies himself in that design, he must succeed, whatever the difficulties. That man will become Grand Vizier or Pope.”

Concentrate on a single goal, a single task, and beat it into submission. In the world of power you will constantly need help from other people, usually those more powerful than you. The fool flits from one person to another, believing that he will survive by spreading himself out. It is a corollary of the law of concentration, however, that much energy is saved, and more power is attained, by affixing yourself to a single, appropriate source of power. The scientist Nikola Tesla ruined himself by believing that he somehow maintained his independence by not having to serve a single master. He even turned down J. P. Morgan, who offered him a rich contract. In the end, Tesla’s “independence” meant that he could depend on no single patron, but was always having to toady up to a dozen of them. Later in his life he realized his mistake.

All the great Renaissance painters and writers wrestled with this problem, none more so than the sixteenth-century writer Pietro Aretino. Throughout his life Aretino suffered the indignities of having to please this prince and that. At last, he had had enough, and decided to woo Charles V, promising the emperor the services of his powerful pen. He finally discovered the freedom that came from attachment to a single source of power. Michelangelo found this freedom with Pope Julius II, Galileo with the Medicis. In the end, the single patron appreciates your loyalty and becomes dependent on your services; in the long run the master serves the slave.

Finally, power itself always exists in concentrated forms. In any organization it is inevitable for a small group to hold the strings. And often it is not those with the titles. In the game of power, only the fool flails about without fixing his target. You must find out who controls the operations, who is the real director behind the scenes. As Richelieu discovered at the beginning of his rise to the top of the French political scene during the early seventeenth century, it was not King Louis XIII who decided things, it was the king’s mother. And so he attached himself to her, and catapulted through the ranks of the courtiers, all the way to the top.

It is enough to strike oil once—your wealth and power are assured for a lifetime.

Tying yourself to a single source of power has one preeminent danger: If that person dies, leaves, or falls from grace, you suffer. This is what happened to Cesare Borgia, who derived his power from his father, Pope Alexander VI. It was the pope who gave Cesare armies to fight with and wars to wage in his name. When he suddenly died (perhaps from poison), Cesare was as good as dead. He had made far too many enemies over the years, and was now without his father’s protection. In cases when you may need protection, then, it is often wise to entwine yourself around several sources of power. Such a move would be especially prudent in periods of great tumult and violent change, or when your enemies are numerous. The more patrons and masters you serve the less risk you run if one of them falls from power. Such dispersion will even allow you to play one off against the other. Even if you concentrate on the single source of power, you still must practice caution, and prepare for the day when your master or patron is no longer there to help you.

Finally, being too single-minded in purpose can make you an intolerable bore, especially in the arts. The Renaissance painter Paolo Uccello was so obsessed with perspective that his paintings look lifeless and contrived. Whereas Leonardo da Vinci interested himself in everything—architecture, painting, warfare, sculpture, mechanics. Diffusion was the source of his power. But such genius is rare, and the rest of us are better off erring on the side of intensity.