The Rise of Universality A. A TWOFOLD PURPOSE
In the nineteenth century, lawyers seeking to explain the purposes of trademark protection might conceivably have been content to enunciate only a "private property" rationale, focusing only on the trademark's function of channeling profits to the enterprise whose goodwill was associated with the mark. This alone, it seems, might have been an ample justification for trademark protection, as it was for patent and copyright protection. 1 Instead, however, nineteenth-century American legal thinkers repeatedly felt it necessary to emphasize the simultaneous significance of trademarks to the consuming public.
This tendency found its earliest judicial expression in 1849, in the New York City Superior Court's opinion in Amoskeag Manufacturing Co. v. Spear. 2 That case arose from the defendant's use on cloth of marks resembling emblems the plaintiff used on its own similar fabrics. Before modifying a lower court's injunction against the defendant, Justice John Duer set forth "the general rules" of trademark law, as he understood them. In particular, he focused on the linked interests of the public and the trademark owner--protecting a manufacturer's "unquestionable right" to use trademarks was "not only the evident duty of a court as an act of justice," he asserted, "but the interests of the public, as well as of individuals, require that the necessary protection shall be given." 3
Duer's conception of the public interest had two distinct components, each intimately bound up with the trademark owner's private interest. First, trademark protection was likely "to produce and encourage a competition by which