Gottschalk v Benson

Posted by Anton Hughes on Thursday, April 06, 2006 with No comments


Gottschalk, Acting Commissioner for Patents v Benson et al (1972) 409 U.S. 63; 93 S.Ct. 253


US Supreme Court


Patent for the "programmed conversion of numerical information in general purpose digital computers", more specifically "a method for converting binary-coded decimal (BCD) numerals into pure binary numerals. The claims were not limited to any particular art or technology, to ary particular apparatus or machinery, or to any particular end use" ( per Douglas J at 64)


The claimed invention was held to be non-patentable subject-matter as an attempt to patent an idea, rather than a process.


  • the method was so abstract as to cover both known and unknown uses
  • the end use could vary and could be performed through any machinery, existing or future or without any apparatus at all
  • the mathematical formula involved had no substantial practical application except in connection with a digital computer
  • the result of granting the patent would be to improperly grant a patent for an idea


This was the first, and fundamental in many ways, case to deal with the patentability of computer programs in the Supreme Court. It is of central relevance both because almost all subsequent jurisprudence built from here onwards. It launched the difficult "mathematical algorithm" test for patentability.


Douglas J

[65] A digital computer, as distinguished from an analog computer, operates on data expressed in digits, solving a problem by doing arithmetic as a person would do it by head and hand.

[65] A procedure for solving a given type of mathematical problem is known as an 'algorithm'. The procedures set forth in the present claims are of that kind; that is to say, they are a generalized formulation for programs to solve mathematical problems of converting one form of numerical representation to another. From the generic formulation, programs may be developed as specific applications.

[67] The method sought to be patented varies the ordinary arithmetic stpes a human would use by changing the order of the steps, changing the symbolism for writing the multiplier used in some steps, and by taking subtotals after each successive operation. The mathematical procedures can be carried out in existing computers long in use, no new machinery being necessary. And, as noted, they can also be performed without a computer.

[67] The Court stated in Mackay Co v Radio Corp 306 US 86, 94 that "while a scientific truth or the mathematical expression of it, is not a patentable invention, a novel and useful structure created with the aid of knowledge of scientific truth may be." That statement followed the longstanding rule that :an idea of itself is not patentable." Rubber Tip Pencil Co v Howard 20 Wall 498, 507. "A principle, in the abstract, is a fundamental truth; an original cause; a motive; these cannot be patented, as no one can claim in either of them an exclusive right." Le Roy v Tatham, 14 How. 156, 175. Phenomena of nature, though just discovered, mental processes, and abstract intellectual concepts are not patentable, as they are the basic tools of scientific and technological work. As we stated in Funk Bros Seed Co v Kalo Co, 333 US 127, 130, "He who discovers a hitherto unknown phenomenon of nature has no claim to a monopoly of it which the law recognizzes. If there is to be invention from sucha  discovery, it must come from the application of the law of nature to a new and useful end." We dealt there with a "product" claim, [68] present case deals with a "process" claim. But we think the same principle applies.

[68] Here the "process claim is so abstract as to cover both known and unknown uses of the BCD to pure binary conversion. The end use may (1) vary from the operation of a train to verification of drivers' licences to researching the law boooks for precedents and (2) be performed through any existing machinery or future-devised machinery or without any apparatus.

[69] In Corning v Burden 15 How. 252, 267-268, the Court said "One may discover a new and useful improvement in the process of tanning, dyeing, etc., irrespective of any particular form of machinery or mechanical device."... Those are instances, however, where the use of chemical substances or physical acts, such as temperature control, changes articles or materials. The chemical process or the physical acts which transform the raw material are, however, sufficiently definite to confine the patent monopoly within rather definite bounds.   ***Anton: Cf NRDC/IBM***

[70] Transformation and reduction of an article "to a different state or thing" is the clue to patentability of a process claim that does not include particular machines... [71] It is argued that a process patent must either be tied to a particular machine or apparatus or must operate to change articles or raw materials to a "different state or thing." We do not hold that no process patent could ever qualify if it did not meet the requirements of our prior precedents. It is said that the decision precludes a patent for any program servicing a computer. We do not so hold. It is said that we have before us a program for a digital computer but extend our holding to programs for analog computers. We have, however, made clear from the start that we deal with a rogram only for digital computers. It is said we freeze process patents to old technologies, leaving no room for the revelations of new, onrushing technology. Such is not our purpose. What we come down to in a nutshell is the following. ***emphasis added***

It is conceded that one may not patent an idea. But in practical effect that would be the result if the formula for converting BCD numerals to pure binary numerals were patented in this case. The mathematical formula involved here has no substantial practical application except in connection with a digital computer, which [72] means that if the judgement below is affirmed, the patent would wholly pre-empt the mathematical formula and in practical effect would be a patent on the algorithm itself.

[72] It may be that the patent laws should be extended to cover these programs, a policy matter to which we are not competent to speak. The President's Commission on the Patent System rejected the proposal that these programs be patentable.

[73] If these programs are to be patentable, considerable problems are raised which only committees of Congress can manage, for broad powers of investigation are needed, including hearings which canvass the wide variety of views which those operating in this field entertain. The technological problems tendered in the many briefs before us here indicate to use that considered action by the Congress is needed.


  • Benrey, R Understanding Digital Computers 4 (1964)
  • Wild, "Computer Program Protection: The Need to Legislate a Solution," 54 Corn. L. Rev. 586 (1969)
  • Bender, "Computer Programs: Should They Be Patentable?" 68 Col. L. Rev. 241 (1968)
  • Buckman, "Protection of Proprietory Interest in Computer Programs," 51 J. Pat. Off. Soc. 135 (1969)