Z:gnu-www-ja-eldred-amicus--10b736-In the sphere of copyright, th/en

In the sphere of copyright, the limited time requirement protects the public domain, by providing for its constant enrichment. The public domain is an essential resource of our constitutional system of free expression. As this Court has previously recognized, several aspects of the copyright system represent constitutionally-required limitations on the nature of the monopoly Congress is empowered to grant. The limited term is not only a particularly important constitutional limitation on Congressional power by virtue of its presence in the text itself&mdash;which goes beyond the textually-implicit limitations of fair use and the idea-expression dichotomy&mdash;but also in the function it serves: the protection of the common resource of the public domain.