His primary point is that ideas are by nature designed to spread for the benefit of society and are not inherently to be made a subject of property - and thus if a society decides to deny to inventors any rights to exclusive claim on an idea, no one has any reason to complain.
In his words:
"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. Society may give an exclusive right to the profits arising from them, as an encouragement to men to pursue ideas which may produce utility, but this may or may not be done, according to the will and convenience of the society, without claim or complaint from any body."
This is a philosophical argument against the idea of patents generally.
Jefferson lost this argument.
Thus, the Patent (and Copyright) Clause of the Constitution (Article I, sec. 8, cl. 8) provides that the Congress shall have the 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." In the first U.S. Patent Act (Act of April 10, 1790, 1 Stat. 109, 110), Congress implemented its constitutional authority to sanction patent monopolies by defining patentable subject matter very broadly, to include "any useful art, manufacture, engine, machine, or device, or any improvement therein." Congress amended the Act in 1793 and then again in 1952, so that today it reads as to the idea of "patentable subject matter" as follows (35 U.S.C. sec. 101): "Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title."
Jefferson made a second very important point in his 1813 letter, and this bears directly on the philosophical dispute underlying the patentability of process or software patents (of course, he did not discuss it in terms of software).
This second point deals with the idea that new uses for old machines or processes should not constitute patentable subject matter.
Jefferson believed that a "machine of which we were possessed, might be applied by every man to any use of which it is susceptible, and that this right ought not to be taken from him and given to a monopolist, because the first perhaps had occasion so to apply it."
In essence, the Jeffersonian position amounted to saying that society was free if it liked to grant limited monopolies on useful ideas that had utility for commerce but there was no inherent right in an inventor to claim such a monopoly - it all depended on the judgment of society. If, however, a society had once decided to grant such monopolies in order to promote commerce, then the monopoly should extend only to the original invention and not to any new use made of it thereafter. Why? Because ideas are meant to be freely transferred for the benefit of society, including the free application of any "machine" by any person to any use of which it is susceptible and, as Jefferson put it, "this right ought not to be taken from him and given to a monopolist."
While Jefferson had lost on the broader idea of abrogating patent protection generally, the more limited idea that discoveries of new uses for old machines or processes were not patentable subject matter did hold sway for quite a while in leading U.S. judicial decisions. For example, in Roberts v. Ryer, 91 U.S. 150, 157 (1875), the Supreme Court held that "it is no new invention to use an old machine for a new purpose."
In 1952, however, Congress explicitly overturned this line of judicial decisions. Specifically, it defined as a patentable process any "process, art, or method" and specified that this included "a new use of a known process, machine, manufacture, composition of matter, or material." (35 U.S.C. sec. 100(b)).
Of course, this 1952 amendment to the Patent Act laid the foundation for a significant expansion of "process" patents and specifically for the adoption of software patents. Why? Because, in a world of general-purpose computing devices, all kinds of existing machines and processes are "susceptible to new uses." Indeed, this is the very nature of software, which can apply to an almost infinite range of potential uses. Once the principle was established that such new uses fell within the statutory definition of "patentable subject matter," then a broad array of such patents could be issued, subject only to meeting other requirements of patentability such as novelty, non-obviousness, utility, etc.
With the modern development of the free and open software movements, the old philosophical debate has taken on new life but the prospects of the "free" side winning this debate, in my view, are likely doubtful. The legal tradition is deeply entrenched in favor of patents, as are the commercial interests. One is left, then, with what amounts to a philosophical argument that patents (or at least process patents) are bad.
Insofar as the law is concerned, the issue will be addressed in the Supreme Court's forthcoming decision in Bilski, expected this year. Beyond that, relevant arguments must be addressed to Congress, which does have the authority to redefine what constitutes patentable subject matter and hence the theoretical power to abolish software patents in general.
Sounding off on blogs definitely furthers the momentum for change but a lot more would be needed to effect a change of view on issues that are so deeply rooted in U.S. history and legal tradition. So long as this remains primarily an ideological position of the free/open software movement, and nothing more, it will likely languish along with the old Jeffersonian sentiment that today sounds so quaintly out of date. I am not saying this in a patronizing way. For something to come of this besides just sounding off, a major shift in mindset has to occur in society generally, and I don't see any evidence of this as yet.
The free software movement is not the only movement to reach this conclusion.
The libertarian tradition itself has now reached a point of consensus regarding the idea of intellectual property, which is to abolish it.
This is a revolution that took place over ten years. It was slow and gradual, but now it is at the point at which all of mises.org, a libertarian think-tank is now licensed all their content under creative common attribution. It also cumlinates with mises.org carrying two book making the case against IP, which is Against Intellectual Property, and a non-Austrian book, Against Intellectual Monopoly.
The free software movement now have allies with the radical libertarians and some of the key major thinker of libertarianism.(Ironically, it shared so many computer programmers as to blur the line somewhat)
Groklaw has been fantastic in exposing the fallacies of software patent lawsuits.
Stallman -- we owe a tremendous debt to him in this regard.
But the way America works, nothing really moves in this lousy country unless you band together into a Political Action Committee and lobby Congress with perks. That's how the software patent law got created in the first place, no thanks to Microsoft, Apple, and Lotus, who got that ball rolling.
And imagine how we sound to a politician. Companies like Microsoft and Apple get some time with politicians easily, and make the pitch that they just want to protect the competition from reselling functionality that they offer. I can see a lot of dumb politicians supporting that idea, especially when compared with the pharma industry. And then we anti-software patent guys come in -- first, we'd be lucky to get a couple seconds to say hello. Second, our pitch would be that software patents stifle innovation, rather than grow it, but would have little proof. Also, every other technology industry has a patent law, so the Congressmen would be like, "Why not software, too? Why should that be so special?" And if you try to tell them that sometimes there's like only 4 optimal ways to do a given task sometimes, and therefore we shouldn't be punished for it, they just wouldn't grasp that concept. If you run to the Republicans, they would consider you anti-capitalist. (And I say that even though I mostly vote Republican.) If you run to the Democrats, they would say that these big companies like Microsoft and Apple bankroll their campaigns, so there's no way they would not support those proprietary agendas. There's no way out except through the courts.
In our agenda, we come off as a bunch of disorganized geeks, and politicians don't seem to mix well with geeks, especially disorganized ones. In the proprietary, pro software patent agenda, they come off as established businessmen and millionaires, so politicians love them.
If anyone has a better idea, I'd like to hear it.
Unless there is a majority consenus(66% agree on course of action for example), we wouldn't be able to act as a force for patent reform or even abolishment!
Repeat this theme to all the protectors of property rights out there...