I occasionally  dig into the available Founding-era record to see what we might be able to glean from the Founders’ words with relevance to modern debates on patent law and policy. With the recent focus on patentable subject matter, I thought it was a good time to point out that Jefferson had neatly summarized the core of the debate on at least one aspect of patentable subject matter, over 200 years ago.
Evans’ Milling Patent
Jefferson had been involved in a debate over whether a particular milling patent was valid. Inventor Oliver Evans1 had obtained a patent on certain machinery used in milling flour and attempted to convince other millers to pay him to convert their mills to his technology. This was complicated by the fact that Evans’ patent had expired and was revived by a special act of Congress a few years later. During the time the patent was not in force, some millers had incorporated his invention into their own mills. When millers proved uninterested in paying Evans to convert their mills to his patented invention, Evans began suing millers—something of a prelude to failed modern companies falling back on patent monetization.
One of the participants in the debate over Evans’ patent, Isaac McPherson, wrote to Jefferson. McPherson believed Jefferson might have evidence that Evans’ invention wasn’t actually a new discovery but simply old technology. Jefferson responded in a letter to McPherson; the letter included Jefferson’s famous parable of the candle.2 McPherson published Jefferson’s letter, and Evans wrote to Jefferson to complain. Jefferson, faced with Evans’ insistence that he was entitled to a patent on not just the machine but on the principle he had devised, regardless of the machine that carried it out, wrote back.
In his letter to Oliver Evans, Jefferson said “I can concieve [sic] how a machine may improve the manufacture of flour: but not how a principle abstracted from any machine, can do it. It must then be the machine, and the principle of that machine which is secured to you by your patent.”
This is the essence of Alice and of abstract idea case law. An abstract principle is not patentable; a specific machine, embodying a specific principle, is.
- There was at least some debate over whether he actually invented much of the technology in his patent, or whether he learned it from another miller, or whether it was simply an application of well known technology. Ultimately, it appears that his patent was found to be either invalid or defective by the Supreme Court. ↵
- Jefferson’s involvement in the debate long predates his letter; he had originally granted Evans’ patent as Secretary of State, and later signed the reviving law as President. However, in his letter to McPherson, Jefferson makes clear that he had understood the law not to revive the patent with respect to anyone who had put up their mill machinery during the period in which it was expired. Evans interpreted the law differently. ↵