It is clear the Framers did not buy into the "if this much protection is good, more must be better" line of reasoning.
US Constitution, Section 8, Clause 8: 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;
You may breathe freely, without a tax, the same air another man has breathed, and think a thought someone else may have thought, also without a tax. Yet you own the breath as it was breathed, whilst in you, and the thought, too, whilst it is in your mind. These are not "public domains", these are private things.
In the clause 8, an exclusive right is secured -- secured by the government. Why is that governmental action needed? Becuase a man, himself, has not a chance of securing any such right, even were he a powerful man and willing to use force to do so, and in an extravagantly widespread way. Not even all the agencies of government alone can secure that right completely, for all the force and authority they can muster.
Why? Because you could still invent, discover, or create the same thing youself at any time in any place, perhaps as a copy or by influence, or perhaps by orginality. The thought, the idea and what you cause to follow from it are your property, they are what you can hold. Nor are they "public domain" -- say by holding your copied machine you have no intent of letting others use it.
Government can restrict very effectively your access to a place or ban the sales of this thing or that. But you retain the ability to create and construct, and no government will ever have the power, save by imprisonment, of taking that away.
So what is meant in the statement "secure exclusive rights"? And what can an honest charter of government mean by that boldness?