The Traditional Burdens for Final Injunctions in Patent Cases c.1789 and Some Modern Implications

This Article reassesses the first two eBay factors for final injunctions—irreparable injury and the inadequacy of legal remedies—in light of traditional equitable principles. Tracking most closely with tradition would require the Federal Circuit to recognize that in patent cases: (1) an injury it seeks to redress with a final injunction is future infringement itself, not just follow-on harms caused by future infringement; (2) it can presume future infringement from past infringement; (3) it can presume that legal remedies are inadequate to remedy future infringement; and (4) it need not require a plaintiff to show that alternative equitable remedies, like ongoing royalties, would inadequately redress future infringement. Moreover, the Federal Circuit can recognize, without relying on presumptions, that the burden on the first two eBay factors is not onerous. A patentee can satisfy them by showing that a defendant is likely to infringe again and that any legal damages awarded at trial did not fully compensate the patentee for the life of the patent