The Argument in Favour of the False Promise Doctrine

I have been critical of the false promise doctrine in past posts, but few arguments are entirely one-sided. The argument in favour of the false promise doctrine is obscured because the traditional justification is based on the theory that the Crown has been deceived in the grant. This theory is unpersuasive in the modern patent system in which a patent is obtained as of right for an invention that is substantively patentable. So, Blanco White §4-403 cites Hatmaker v Nathan (1919) 36 RPC 231 (HL) for the proposition that “where a patentee promises (expressly or impliedly) the attainment of a certain result, and this is not obtained, . . .the patent will be invalid: for ‘protection is secured by the promise of results; it does not, and ought not to, survive the proved failure of the promise to produce the results,’” and then in the footnote he remarks acerbically that “It is not, of course, in actual fact; but the House of Lords has repeated this dictum until it is of unimpeachable authority.”

The better defence of the doctrine is based on the modern understanding of the purpose of the utility doctrine, which is to govern how far upstream in the R&D process an invention may be patented.
In the famous words from Brenner v Manson (1966) 383 US 519: “a patent is not a hunting license. It is not a reward for the search, but compensation for its successful conclusion.” For that reason a patent must deliver some current benefit at the claim date. Further, it is not enough that that utility is known only to the inventor. In must also be known to the skilled reader: “It should not be left to the skilled reader to find out how to exploit the invention by carrying out a research programme” T 898/05 [6]. Consequently, in the EPO, if the description does not state a utility and the utility would not be apparent to a skilled person in light of common general knowledge, the patent will be invalid for lack of industrial application, whether or not there is a use known to the patentee (Examination Guidelines C.IV.5.4). That is explicitly stated for DNA sequences in the Biotechnology Directive, Art 5(3) but the principle is of broader application. It follows that if the utility of the invention would not be apparent to the skilled reader in light of common general knowledge, and the patentee states a utility in the specification, but the stated utility is incorrect, the patent would be invalid for lack of industrial applicability, again whether or not the patentee knows the true utility.

This begins to approach the Canadian false promise doctrine. What if there is no utility that would be apparent to a skilled person, and the patent clearly discloses two uses in the specification, one of which is true and the other of which is false. That is essentially the problem in Re Alsop’s Patent (1907) 24 RPC 733, the leading English case under pre-1977 law.* The pressing problem with the doctrine in current Canadian law, in my view, is that there is typically a correct utility that is disclosed or obvious to a skilled person and the second ‘false’ promise is extracted from a sometimes technical and legalistic reading of the disclosure. When the invention does deliver a current benefit which is in fact known to those skilled in the art from reading the specification in light of the cgk, it seems wrong to hold the patent invalid. The difficulty lies in distinguishing this in principle from the proposition that a patent is invalid if it states an incorrect use and there is no other use that would be known to the skilled reader. Should we say that it is enough if one correct use is disclosed? Should it matter how easy it is for the skilled person to determine which use is correct? I believe there is a real issue here, and it is unfortunate that the underlying problem has been obscured by the entrenchment of the false promise doctrine in an archaic form.

*The claimed invention in Alsop’s Patent was a process of treating flour with ionized air. The specification clearly stated that this process both bleached the flour and increased its protein content. The process did effectively bleach the flour but in an action for revocation of the patent by petitioners who wished to use it for bleaching, it was proved that the process did not increase the protein content. The process bleached flour using a nitrogen oxide gas which left a nitrogen residue in the flour. The patentee has sent a sample to an independent laboratory for analysis, without informing them of the process, and the lab had interpreted the excess nitrogen as being due to increased protein content. The patent was revoked for failure to deliver on the promise to increase protein content