No natural rights theory justifies strong intellectual property rights. More specifically, no theory within the entire domain of natural rights thinking – encompassing classical liberalism, libertarianism and left-libertarianism, in all their innumerable variants – coherently supports strengthening current intellectual property rights. Despite their many important differences, all these natural rights theories endorse some set of members of a common family of basic ethical precepts. These commitments include non-interference, fairness, non-worsening, consistency, universalisability, prior consent, self-ownership, self-governance, and the establishment of zones (...) of autonomy. Such commitments have clear applications pertaining to the use and ownership of created ideas. I argue that each of these commitments require intellectual property rights to be substantially limited in scope, strength and duration. In this way the core mechanisms of natural rights thinking ensure a robust public domain and categorically rule out strong intellectual property rights. (shrink)