"As we have explained, originality is a constitutionally mandated prerequisite for copyright protection. The Court’s decisions announcing this rule predate the Copyright Act of 1909, but ambiguous language in the 1909 Act caused some lower courts temporarily to lose sight of this requirement. The 1909 Act embodied the originality requirement, but not as clearly as it might have. The subject matter of copyright was set out in §§ 3 and 4 of the Act. Section 4 stated that copyright was available to “all the writings of an author.” By using the words “writings” and “author” – the same words used in Article I, § 8, of the Constitution and defined by the Court in The Trade-Mark Cases and Burrow-Giles – the statute necessarily incorporated the originality requirement articulated in the Court’s decisions. It did so implicitly, however, thereby leaving room for error. Section 3 was similarly ambiguous. It stated that the copyright in a work protected only “the copyrightable component parts of the work.” It thus stated an important copyright principle, but failed to identify the specific characteristic—originality—that determined which component parts of a work were copyrightable and which were not. Most courts construed the 1909 Act correctly, notwithstanding the less-than-perfect statutory language. They understood from this Court’s decisions that there could be no copyright without originality."