The constitution is rather pithy. It simply states that:
"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."
No incentive mentioned either. It's just understood that providing the exclusive right for a limited time will somehow promote progress. So you need to go to the founders' more expensive writings and generally understood truths of the time to argue intent.
"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."
No incentive mentioned either. It's just understood that providing the exclusive right for a limited time will somehow promote progress. So you need to go to the founders' more expensive writings and generally understood truths of the time to argue intent.