Brief for Samuel L. Bray as Amicus Curiae Supporting Petitioners, Merck & Co. v. Gilead Sciences, Inc.

One of the long-standing maxims of equity is that “he who comes into equity must come with clean hands.” It is closely related to the maxim that “he who seeks equity must do equity.” These equitable principles are “an historical reflection of the fact that courts of equity began as courts of conscience.” In this country and throughout the common law world, unclean hands has tradition- ally been a defense to equitable claims, but not to legal claims. Yet in the case below the Federal Circuit applied the equitable defense of unclean hands to a legal claim for damages for patent infringement. The Federal Circuit repeatedly relied on precedents of this Court that characterize unclean hands as an equitable defense that constrains a court of equity. The Federal Circuit provided no support whatsoever for applying the equitable defense of unclean hands to a legal claim for damages, especially when that equitable defense would displace the verdict of a jury.