Understood in this manner, copyrights and patents are merely specific applications of the principle of voluntary contracts. Their enforcement is therefore entirely consistent with and implied by the concepts of property, contracts, and the free market as we have already developed them in this course. Intellectual property rights are sometimes assumed to be a special category of rights, supposedly imposed in order to create economic incentives toward discovery and innovation. As we have developed them here, however, they are simply a specific case, already implied by our understanding of property rights as they apply to material objects. Although they do happen to create the economic incentives just mentioned, their true moral justification lies, not in any "social" benefit, but in the ideas of ownership and of freedom of action, including freedom of contract—ideas which we developed earlier in the course.