摘要:Patent law is in flux, with recent disputes and changes in doctrine fueled by increased attention from the Supreme Court and en banc activity by the Federal Circuit. The natural reaction is to analyze each doctrinal area involved on its own. Upon a closer look, however, many patent cases concern a single, fundamental dispute. Conflicts in opinions on such issues as claim interpretation methodology and the written description requirement are really disagreements over which “invention” the courts should be considering. There are two concepts of invention currently in play in patent decisions. The first is an “external invention” definition, in which courts define the invention by the detailed technology discussion in the patent specification’s descriptions and drawings. Other decisions invoke a “claim-centered invention” definition, which relies almost exclusively on the claim, a single sentence at the end of the patent. Judging these two definitions against common patent theories can help to determine which best fits the theories’ narratives. This Article concludes that the external invention is more favorable because it grounds exclusivity in what the inventor has actually done or plans to do and, accordingly, is more likely to comport with common patent theories.