Historical Kinship & Categorical Mischief: The Use and Misuse of Doctrinal Borrowing in Intellectual Property Law

Analogies are ubiquitous in legal reasoning, and, in copyright jurisprudence, courts frequently turn to patent law for guidance. From introducing doctrines meant to regulate online intermediaries to evaluating the constitutionality of resurrecting copyrights to works from the public domain, judges turn to patent law analogies to lend ballast to their decisions. At other times, however, patent analogies with copyright law are quickly discarded and differences between the two regimes highlighted. Why? In examining the transplantation of doctrinal frameworks from one intellectual property field to another, this Article assesses the circumstances in which courts engage in doctrinal borrowing, discerns their rationale for doing so, identifies whether certain patterns of borrowing exist, and scrutinizes the value, propriety, and impact of such borrowing. By tracing the different strains that animate the courts' analogical jurisprudence in patent and copyright law, the Article builds on broader insights from the scholarship on legal borrowing and offers guidance on how to approach analogies between related legal regimes in a more disciplined fashion. In the end, the Article seeks to provide a better understanding of what juridical techniques courts may deploy to strengthen the efficacy of borrowing-so that importation of legal doctrine can do more good than harm-in intellectual property law and more generally.