In the nation's history, 112 people have served on the Supreme Court of the United States. Suppose that we were to select the all-time greats. Who would make the cut?

To answer that question, we need a metric. It makes sense to consider two factors: historical significance and legal ability. It would be too contentious to include only those justices with whom one agrees, so let's make this list ideology-free. We'll also exclude the current justices, because it is too early to tell whether any will count among the all-time greats.

Without further ado, here are the greatest Supreme Court justices, along with the year they were appointed to the court:

1) John Marshall (1801). If the court has a Babe Ruth, it's John Marshall. The authority of the national government, as Americans understand it, owes a great deal to Marshall's early opinions. Marshall can claim primary responsibility for the fundamental principles that continue to organize our law. One example is the broad regulatory power of Congress. Another example is the power of judicial review itself, which authorizes the court to strike down acts of Congress and state legislatures.

2) Oliver Wendell Holmes Jr. (1902). Holmes's mind was like a razor, and he is widely believed to have been the greatest writer in the court's history. Actually, he was the second- greatest, but that's not bad.

Holmes' defining contribution was an insistence on a modest role for the federal judiciary. His pithy explanation: "If my fellow citizens want to go to Hell I will help them. It's my job." Holmes insisted that a constitution "is made for people of fundamentally differing views." If Marshall was the court's Babe, Holmes was its Hank Aaron — the greatest home-run hitter who didn't use steroids.

3) Louis Brandeis (1916). Brandeis is often grouped with Holmes as a great early proponent of judicial modesty, as well as an ardent defender of freedom of speech. But his sensibility was altogether different. His eyes were on the heavens. He believed that "the greatest menace to freedom is an inert people." He wrote: "Those who won our independence believed that the final end of the State was to make men free to develop their faculties, and that, in its government, the deliberative forces should prevail over the arbitrary. They valued liberty both as an end, and as a means. They believed liberty to be the secret of happiness, and courage to be the secret of liberty."

4) Felix Frankfurter (1939). Many liberals were, and remain, deeply disappointed with Frankfurter, who toed no party line. A powerful critic of Warren court activism, Frankfurter argued for small, incremental steps. He wanted to avoid the most fundamental questions, and he made powerful arguments for his minimalist approach. He was wise, and he was deep, and he is underrated; it's high time for a Frankfurter revival.

5) Robert Jackson (1941). A piercing intellect and the greatest writer in the history of the court, Jackson did not go to law school. (No smirking, please.) Jackson helped to develop doctrines that govern contemporary understandings of free speech and separation of powers, above all the authority of the president.

No other justice wrote sentences like this: "Compulsory unification of opinion achieves only the unanimity of the graveyard." Or this: "If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion, or other matters of opinion, or force citizens to confess by word or act their faith therein." Jackson made Supreme Court opinions sing.

6) Earl Warren (1953). Under Warren's leadership, the court reformed American society. It struck down school segregation; called for a rule of one person, one vote; required the Miranda warnings; offered broad protection to freedom of speech; expanded the reach of the Fourth Amendment; and abolished the poll tax. That's a very partial picture. Warren did not have the analytic power of others on this list, but none of them had a larger impact.

7) William Brennan (1956). Brennan may well have been the most influential member of the Warren court. If Warren was its heart, Brennan was its brain. An unfailingly kind and gracious man, Brennan served on the court far longer than Warren, and he somehow managed to cobble together rights-protecting majorities long after the liberal majority left the bench.

8) William Rehnquist (1972). In his early years on the court, Rehnquist was called "the Lone Ranger" because his conservative views, defended with great power, were often set out in lonely dissents. When I was clerking at the court in the early 1980s, Rehnquist told me that the court was like a ship that had become badly tilted — and he made a gesture, signaling that the court had tilted left.

Named chief justice in 1986, Rehnquist was no longer alone. Reducing federal power and limiting the reach of numerous Warren court rulings, Rehnquist redirected constitutional law in countless areas. More than any other justice in recent decades, Rehnquist succeeded in restoring what he considered to be the right constitutional balance.

Please e-mail me at Casssunstein@bloomberg.net and let me know who you think were the greatest Supreme Court justices.