When citizens of the United States propose a discussion of any subject of public policy which is specifically mentioned in the national Constitution, the constitutional provision is likely to be the most appropriate point of departure. The statesmen who framed the great charter of 1787 were on the alert in the public interest when, after providing that "All legislative Powers herein granted shall be vested in a Congress of the United States,"1 they added that
The Congress shall have Power . . .
To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries