In this article, I introduce the interaction between intellectual property (IP) and antitrust law. I describe the ways in which these two important areas of government regulation are and are not in tension, and discuss the history of the relationship between these laws. I argue that IP and antitrust have cycled between over- and under-protection, and that we are currently (and mistakenly) conditioned to think of private property and private ordering as efficient in and of themselves, rather than as efficient only in the context of robust market competition. Further, I argue that antitrust can serve the goals of innovation and dynamic efficiency directly in circumstances in which competition, not monopoly, serves as a spur to innovation. The goal of the IP and antitrust laws should be to seek a robust balance between competition and monopoly in the service of dynamic efficiency. When IP laws are strong, antitrust laws should also be strong, and vice versa.