This Article endeavors to offer a unified explanation for a wide variety of copyright doctrines, including the fixation requirement, the merger doctrine and the requirement that eligible works demonstrate at least a modicum of creativity. That explanation: these doctrines mitigate what would otherwise be difficult problems of proof. More specifically, each of these doctrines serves to deny protection in cases particularly prone to evidentiary complexity. The implicit logic is that, in these cases, the social cost of further litigation would likely outweigh the social benefit derived from offering copyright protection in the first place. Understanding these doctrines in this light offers a number of insights into their appropriate scope and application. For instance, the evidentiary theory resolves a long-standing debate over whether factual databases should be eligible for copyright protection (they should), and it also makes clear significant weaknesses in the current legal treatment of both derivative and jointly authored works.