In his Republic, Plato recommended a philosopher king, a leader who complemented political power with intellectual insight. America’s revolutionary generation created a republic but substituted a president for a king. The closest they came to a philosopher was Thomas Jefferson.
Jefferson was pretty close an approximation. None of his American contemporaries devoted so much time to understanding the world from first principles. Jefferson's Notes on the State of Virginia surveyed the human and natural history of his home province and state with remarkable sophistication for his era.
As philosophers do, Jefferson strove for consistency in his thought. And he tried to fit his actions to his thought. This was easier when he was out of power and was able simply to critique the actions of others — that is, when he could play the philosopher alone. It grew harder when he held power himself — when the philosopher became the king.
In philosopher mode, Jefferson critiqued the Constitution of 1787 as potentially permitting too much power to the national government, at the expense of the states and the people. He stoutly opposed the actions of Alexander Hamilton when the first secretary of the treasury engineered federal assumption of state debts from revolutionary war and persuaded Congress to create a national bank. He decried the Alien and Sedition Acts of 1798 as gross overreach by the legislative and executive branches and proposed a theory of state nullification of federal law as an appropriate response.
Jefferson's criticisms of government contributed to his election as president in 1800. At which point he had to decide between being philosopher and being king.
The difference emerged most sharply when Napoleon Bonaparte of France offered to sell Louisiana to the United States. Jefferson's studies of history and geography had convinced him of the absolute importance of Louisiana — the western half of the watershed of the Mississippi River — to America's security and future prosperity. Yet his study of the Constitution revealed no authority for the president or Congress to purchase new territory. His critique of Hamilton had rested on a narrow reading of the Constitution, based on the premise that if the Constitution did not expressly authorize an action, that action was forbidden.
Jefferson’s choice became: his philosophical scruples or the welfare of the United States?
He considered trying to have it both ways. If he could persuade Congress and the states to amend the Constitution and provide land-purchasing authority, his problem would go away. But amending the Constitution is slow business, and while Congress and the states pondered, Napoleon might change his mind and rescind his offer to sell.
Jefferson concluded that the American people, through their electors, had chosen him to be president, not to be a philosopher. He could continue to philosophize on his own time. But as president he had to act in the interest of the United States. And the interest of the United States dictated that he swallow his scruples and seize Napoleon's offer.
Jefferson's opponents delighted in his discomfiture. Many had found his philosophizing tedious. Now that it appeared to have been hypocritical, they threw it back in his face.
Jefferson had expected as much. But it turned out he was an even better politician than he was a philosopher. He reckoned accurately that his opponents wouldn't indulge their jibes to the point of blocking the purchase, which everyone recognized as the bargain of the century. They took their shots, he took the hits, and future generations of Americans benefited from the doubling of acreage into which to expand.
What's the lesson for other leaders?
Philosophize if you are so inclined. The practice is good mental exercise, if nothing else. Develop guiding principles and don't abandon them lightly.
But don't let them become a straightjacket against needed action. What were you hired to do? Whose interests did you commit to promote?
Consider those interests as honestly as you can. If they conflict with your scruples, the scruples might have to give way.
You can return to your philosophy in retirement.
I think Jefferson was reading the Constitution far too narrowly. Article 4-Sec3 discusses new states being admitted and not from the splitting off of other states. Where exactly did Jefferson think new states were going to come from? And Articles 1-sec8 allows congress to regulate commerce with foreign nations and buying territory from another nations is certainly commerce and the president can make treaties- what better treaty than to make one to buy the Louisiana territory?
Article 1-Section 8
Congress To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes;
Article 2- Section 2
He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties,
Article 4 - Section 3
New States may be admitted by the Congress into this Union; but no new State shall be formed or erected within the Jurisdiction of any other States and The Congress shall have Power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States
Jefferson took a risk. The president does not have the unilateral power to commit to spend money or acquire territory. At the very least, Congress and the courts could have blocked him. At the worst, he could have been impeached for an abuse of power. Teddy Roosevelt took a similar risk with the Panama Canal.