I read this near the end of Steven Johnson’s book, Where Ideas Come From: The Natural History of Innovation. You can read the entire letter by Thomas Jefferson here. It was written to a Mr. Isaac McPherson, a Boston mill owner, in a patent dispute.
That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density in any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation. Inventions then cannot, in nature, be a subject of property.
Thomas Jefferson to Isaac McPherson
13 Aug. 1813