The Proper Role for the Presumption of Validity

In 2011, the Supreme Court addressed the presumption of validity in Microsoft Corp. v. i4i Ltd. P'ship. It confirmed that the standard of proof for invalidity is clear and convincing evidence. Initially, this opinion was seen by many as preserving the strength of patents. But closer scrutiny reveals that the Supreme Court's analysis does not extend to all invalidity defenses. According to Justice Breyer's concurrence, joined by Justices Scalia and Alito, the presumption of validity only provides protection against factual elements of an invalidity challenge. That concurrence, and the Supreme Court's recent opinion in Nautilus, Inc. v. Biosig Instruments, Inc., suggest that the presumption of validity has no application to purely legal bases for invalidity.