Seven justices today rejected an attempt to make patents easier for judges and juries to find invalid. The Court held that Congress's granting patents a presumption of validity saves patents unless their foes prove a basis for invalidity with "clear and convincing" evidence. Microsoft Corp. v. i4i Ltd. Partnership, No. 10-290 (U.S. June 9, 2011).

The ruling doesn't change the law. Justice Sotomayor's opinion for the Court upheld a rule that has prevailed pretty much forever and for sure since 1952, when Congress passed the current patent statute, including section 282, which states the presumption.

The outcome turned on whether "[a] patent shall be presumed valid" in section 282 by itself implied a tougher test than the usual preponderance of the evidence standard for proving facts. The Court held that the phrase did imply the higher "clear and convincing" hurdle, not least because the Court had for a Great Many years used a common law presumption of validity and deemed the presumption immune to attacks that left the fact-finder merely "dubious" about a patent's validity.

The appeal stemmed from a verdict and judgment against Microsoft in the Eastern District of Texas for $290 million. Microsoft defended itself on the ground, among others, that i4i sold its invention more than a year before filing a patent application, rendering the patent invalid under 35 U.S.C. § 102(b).

Justice Thomas concurred only in the judgment, citing the fact that section 282 did not alter the common law presumption and therefore preserved the common law test for overcoming it. Chief Justice Roberts recused himself and didn't vote on the outcome.