"Justice John Paul Stevens is the greatest Justice in Supreme Court history."

Argues Cliff Sloan, a partner at Skadden, Arps, Slate, Meagher, & Flom and a former Stevens law clerk. A key move in this argument is excluding the Chief Justices on the theory that they have extra powers so it's not a proper comparison. Then Sloan has 4 reasons:

First, his record of protecting and maintaining the rule of law during the “war on terror” stands unique in Supreme Court annals....

Second, Justice Stevens has fundamentally changed – and strengthened – the Court’s jurisprudence regarding personal freedom.... [He] has successfully re-framed the Court’s conceptual framework for personal freedom from a general “privacy” right, which is not mentioned explicitly in the Constitution, to a “liberty” right, which is prominently and explicitly protected in the Constitution....

Third, Justice Stevens has steadfastly sought to enforce the rule of law even when the Presidency hangs in the balance....

Fourth, Justice Stevens has powerfully re-shaped the law in an astonishing range of areas....

Go to the link to see the cases Sloan discusses. I would note that in some of the cases, Stevens has had something akin to the superpower that Sloan used to exclude Chief Justices from the analysis. When the Chief Justice isn't in the majority, the most senior Justice in the majority decides who will write the opinion. As such, over the last 20 years, he's authored many of the important opinions where the liberal side of the Court had the majority. That he wrote the opinion on the side that Sloan prefers isn't the evidence of a personal stamp on the law that Sloan would have us think.

Once Sloan gets to identifying and excluding the the competition for greatest Justice, the argument falls badly apart. He has to really strain to minimize Brandeis, Holmes, Brennan, Story, and the first Justice Harlan. He lost me here, but you've got to give Sloan credit for writing what would be a strong entry in a competition requiring an essay titled "Justice John Paul Stevens is the greatest Justice in Supreme Court history."