with whom Justice Brennan, Justice Marshall, and Justice Blackmun join, dissenting.
The starting point in the proper adjudication of patent litigation is an understanding of what the inventor claims *194to have discovered. The Court’s decision in this case rests on a misreading of the Diehr and Lutton patent application. Moreover, the Court has compounded its error by ignoring the critical distinction between the character of the subject matter that the inventor claims to be novel — the § 101 issue — and the question whether that subject matter is in fact novel — the § 102 issue.
I
Before discussing the major flaws in the Court’s opinion, a word of history may be helpful. As the Court recognized in Parker v. Flook, 437 U. S. 584, 595 (1978), the computer industry is relatively young. Although computer technology seems commonplace today, the first digital computer capable of utilizing stored programs was developed less than 30 years ago.1 Patent law developments in response to this new technology are of even more recent vintage. The subject of legal protection for computer programs did not begin to receive serious consideration until over a decade after completion of the first programmable digital computer.2 It was 1968 be*195fore the federal courts squarely addressed the subject,3 and 1972 before this Court announced its first decision in the area.4
Prior to 1968, well-established principles of patent law probably would have prevented the issuance of a valid patent on almost any conceivable computer program. Under the “mental steps” doctrine, processes involving mental operations were considered unpatentable. See, e. g., In re Heritage, 32 C. C. P. A. (Pat.) 1170, 1173-1177, 150 F. 2d 554, 556-558 (1945); In re Shao Wen Yuan, 38 C. C. P. A. (Pat.) 967, 972-976, 188 F. 2d 377, 380-383 (1951). The mental-steps doctrine was based upon the familiar principle that a scientific concept or mere idea cannot be the subject of a valid patent. See In re Bolongaro, 20 C. C. P. A. (Pat.) 845, 846-847, 62 F. 2d 1059, 1060 (1933).5 The doctrine was regularly invoked to deny patents to inventions consisting primarily of mathematical formulae or methods of computation.6 It was also applied against patent claims in which a mental operation or mathematical computation was the sole novel element or inventive contribution; it was clear that patentability *196could not be predicated upon a mental step.7 Under the “function of a machine” doctrine, a process which amounted to nothing more than a description of the function of a machine was unpatentable. This doctrine had its origin in several 19th-century decisions of this Court/8 and it had been consistently followed thereafter by the lower federal courts.9 *197Finally, the definition of “process” announced by this Court in Cochrane v. Deener, 94 U. S. 780, 787-788 (1877), seemed to indicate that a patentable process must cause a physical transformation in the materials to which the process is applied. See ante, at 182-184.
Concern with the patent system’s ability to deal with rapidly changing technology in the computer and other fields led to the formation in 1965 of the President’s Commission on the Patent System. After studying the question of computer program patentability, the Commission recommended that computer programs be expressly excluded from the coverage of the patent laws; this recommendation was based primarily upon the Patent Office’s inability to deal with the administrative burden of examining program applications.10 At approximately the time that the Commission issued its report, the Patent Office published notice of its intention to prescribe guidelines for the examination of applications for patents on computer programs. See 829 Off. Gaz. Pat. Off. 865 (Aug. 16, 1966). Under the proposed guidelines, a computer program, whether claimed as an apparatus or as a process, was unpatentable.11 The Patent Office indicated, how*198ever, that a programmed computer could be a component of a patentable process if combined with unobvious elements to produce a physical result. The Patent Office formally adopted the guidelines in 1968. See 33 Fed. Reg. 15609 (1968).
The new guidelines were to have a short life. Beginning with two decisions in 1968, a dramatic change in the law as understood by the Court of Customs and Patent Appeals took place. By repudiating the well-settled “function of a machine” and “mental steps” doctrines, that court reinterpreted § 101 of the Patent Code to enlarge drastically the categories of patentable subject matter. This reinterpretation would lead to the conclusion that computer programs were within the categories of inventions to which Congress intended to extend patent protection.
In In re Tarczy-Hornoch, 55 C. C. P. A. (Pat.) 1441, 397 F. 2d 856 (1968), a divided Court of Customs and Patent Appeals overruled the line of cases developing and applying the “function of a machine” doctrine. The majority acknowledged that the doctrine had originated with decisions of this Court and that the lower federal courts, including the Court of Customs and Patent Appeals, had consistently adhered to it during the preceding 70 years. Nonetheless, the court concluded that the doctrine rested on a misinterpretation of the precedents and that it was contrary to “the basic purposes of the patent system and productive of a range of undesirable results from the harshly inequitable to the silly.” Id., at 1454, 397 F. 2d, at 867.12 Shortly thereafter, a similar *199fate befell the “mental steps” doctrine. In In re Prater, 56 C. C. P. A. (Pat.) 1360, 415 F. 2d 1378 (1968), modified on rehearing, 56 C. C. A. P. (Pat.) 1381, 415 F. 2d 1393 (1969), the court found that the precedents on which that doctrine was based either were poorly reasoned or had been misinterpreted over the years. 56 C. C. P. A. (Pat.); at 1366-1372, 415 F. 2d, at 1382-1387. The court concluded that the fact that a process may be performed mentally should not foreclose patentability if the claims reveal that the process also may be performed without mental operations. Id., at 1374-1375, 415 F. 2d, at 1389.13 This aspect of the original Prater opinion was substantially undisturbed by the opinion issued after rehearing. However, the second Prater opinion clearly indicated that patent claims broad enough to encompass the operation of a programmed computer would not be rejected for lack of patentable subject matter. 56 C. C. P. A. (Pat.), at 1394, n. 29, 415 F. 2d, at 1403, n. 29.14
*200The Court of Customs and Patent Appeals soon replaced the overruled doctrines with more expansive principles formulated with computer technology in mind. In In re Bernhart, 57 C. C. P. A. (Pat.) 737, 417 F. 2d 1395 (1969), the court reaffirmed Prater, and indicated that all that remained of the mental-steps doctrine was a prohibition on the granting of a patent that would confer a monopoly on all uses of a scientific principle or mathematical equation. Id., at 743, 417 F. 2d, at 1399. The court also announced that a computer programmed with a new and unobvious program was physically different from the same computer without that program; the programmed computer was a new machine or at least a new improvement over the unprogrammed computer. Id., at 744, 417 F. 2d, at 1400. Therefore, patent protection could be obtained for new computer programs if the patent claims were drafted in apparatus form.
The Court of Customs and Patent Appeals turned its attention to process claims encompassing computer programs in In re Musgrave, 57 C. C. P. A. (Pat.) 1352, 431 F. 2d 882 (1970). In that case, the court emphasized the fact that Prater had done away with the mental-steps doctrine; in particular, the court rejected the Patent Office’s continued reliance upon the “point of novelty” approach to claim analysis. Id., at 1362, 431 F. 2d, at 889.15 The court also announced a new standard for evaluating process claims under § 101: any sequence of operational steps was a patentable process under § 101 as long as it was within the “technological arts.” Id., at 1366-1367, 431 F. 2d, at 893. This standard effectively disposed of any vestiges of the mental-steps doctrine remain*201ing after Prater and Bernhart.16 The “technological arts” standard was refined in In re Benson, 58 C. C. P. A. (Pat.) 1134, 441 F. 2d 682 (1971), in which the court held that computers, regardless of the uses to which they are put, are within the technological arts for purposes of § 101. Id., at 1142, 441 F. 2d, at 688.
In re Benson, of course, was reversed by this Court in Gottschalk v. Benson, 409 U. S. 63 (1972).17 Justice Douglas’ opinion for a unanimous Court made no reference to the lower court’s rejection of the mental-steps doctrine or to the new technological-arts standard.18 Rather, the Court clearly held that new mathematical procedures that can be conducted in old computers, like mental processes and abstract intellectual concepts, see id., at 67, are not patentable processes within the meaning of § 101.
*202The Court of Customs and Patent Appeals had its first opportunity to interpret Benson in In re Christensen, 478 F. 2d 1392 (1973). In Christensen, the claimed invention was a method in which the only novel element was a mathematical formula. The court resurrected the point-of-novelty approach abandoned in Musgrave and held that a process claim in which the point of novelty was a mathematical equation to be solved as the final step of the process did not define patentable subject matter after Benson. 478 F. 2d, at 1394. Accordingly, the court affirmed the Patent Office Board of Appeals’ rejection of the claims under § 101.
The Court of Customs and Patent Appeals in subsequent cases began to narrow its interpretation of Benson. In In re Johnston, 502 F. 2d 765 (1974), the court held that a record-keeping machine system which comprised a programmed digital computer was patentable subject matter under § 101. Id., at 771. The majority dismissed Benson with the observation that Benson involved only process, not apparatus, claims. 502 F. 2d, at 771. Judge Rich dissented, arguing that to limit Benson only to process claims would make pat-entability turn upon the form in which a program invention was claimed. 502 F. 2d, at 773-774.19 The court again construed Benson as limited only to process claims in In re Noll, 545 F. 2d 141 (1976), cert. denied, 434 U. S. 875 (1977); apparatus claims were governed by the court’s pre-Benson conclusion that a programmed computer was structurally different from the same computer without that particular program. 545 F. 2d, at 148. In dissent, Judge Lane, joined by Judge Rich, argued that Benson should be read as a general proscription of the patenting of computer programs regardless of the form of the claims. 545 F. 2d, at 151-152. Judge Lane’s interpretation of Benson was rejected by the majority *203in In re Chatfield, 545 F. 2d 152 (1976), cert. denied, 434 U. S. 875 (1977), decided on the same day as Noll. In that case, the court construed Benson to preclude the patenting of program inventions claimed as processes only where the would pre-empt all uses of an algorithm or mathematical formula. 545 F. 2d, at 156, 158-159.20 The dissenting judges argued, as they had in Noll, that Benson held that programs for general-purpose digital computers are not patentable subject matter. 545 F. 2d, at 161.
Following Noll and Chatfield, the Court of Customs and Patent Appeals consistently interpreted Benson to preclude the patenting of a program-related process invention only when the claims, if allowed, would wholly pre-empt the algorithm itself. One of the cases adopting this view was In re Flook, 559 F. 2d 21 (1977),21 which was reversed in Parker v. Flook, 437 U. S. 584 (1978). Before this Court decided Flook, however, the lower court developed a two-step procedure for analyzing program-related inventions in light of Benson. In In re Freeman, 573 F. 2d 1237 (1978), the court held that such inventions must first be examined to determine whether a mathematical algorithm is directly or indirectly claimed; if an algorithm is recited, the court must then determine whether the claim would wholly pre-empt that algorithm. Only if a claim satisfied both inquiries was Benson considered applicable. 573 F. 2d, at 1245. See also In re Toma, 575 F. 2d 872, 877 (CCPA 1978).
*204In Flook, this Court clarified Benson in three significant respects. First, Flook held that the Benson rule of unpat-entable subject matter was not limited, as the lower court believed, to claims which wholly pre-empted an algorithm or amounted to a patent on the algorithm itself. 437 U. S., at 589-590. Second, the Court made it clear that an improved method of calculation, even when employed as part of a physical process, is not patentable subject matter under § 101. Id., at 595, n. 18. Finally, the Court explained the correct procedure for analyzing a patent claim employing a mathematical algorithm. Under this procedure, the algorithm is treated for § 101 purposes as though it were a familiar part of the prior art; the claim is then examined to determine whether it discloses “some other inventive concept.” Id., at 591-595.22
Although the Court of Customs and Patent Appeals in several post-Flook decisions held that program-related inventions were not patentable subject matter under § 101, see, e. g., In re Sarkar, 588 F. 2d 1330 (1978); In re Gelnovatch, 595 F. 2d 32 (1979), in general Flook was not enthusiastically received by that court. In In re Bergy, 596 F. 2d 952 (1979), the majority engaged in an extensive critique of Flook, concluding that this Court had erroneously commingled “distinct statutory provisions which are conceptually unrelated.” 596 F. 2d, at 959.23 In subsequent cases, the court construed *205Flook as resting on nothing more than the way in which the patent claims had been drafted, and it expressly declined to use the method of claim analysis spelled out in that decision. The Court of Customs and Patent Appeals has taken the position that, if an application is drafted in a way that discloses an entire process as novel, it defines patentable subject matter even if the only novel element that the inventor claims to have discovered is a new computer program.24 The court interpreted Flook in this manner in its opinion in this case. See In re Diehr, 602 P. 2d 982, 986-989 (1979). In my judgment, this reading of Flook — although entirely consistent with the lower court’s expansive approach to § 101 during the past 12 years — trivializes the holding in Flook, the principle that underlies Benson, and the settled line of authority reviewed in those opinions.
II
As I stated at the outset, the starting point in the proper adjudication of patent litigation is an understanding of what the inventor claims to have discovered. Indeed, the outcome of such litigation is often determined by the judge’s understanding of the patent application. This is such a case.
In the first sentence of its opinion, the Court states the question presented as “whether a process for curing synthetic rubber ... is patentable subject matter.” Ante, at 177. Of course, that question was effectively answered many years ago when Charles Goodyear obtained his patent on the vulcanization process.25 The patent application filed by Diehr *206and Lutton, however, teaches nothing about the chemistry of the synthetic rubber-curing process, nothing about the raw materials to be used in curing synthetic rubber, nothing about the equipment to be used in the process, and nothing about the significance or effect of any process variable such as temperature, curing time, particular compositions of material, or mold configurations. In short, Diehr and Lutton do not claim to have discovered anything new about the process for curing synthetic rubber.
As the Court reads the claims in the Diehr and Lutton patent application, the inventors’ discovery is a method of constantly measuring the actual temperature inside a rubber molding press.26 As I read the claims, their discovery is an *207improved method of calculating the time that the mold should remain closed during the curing process.27 If the Court’s reading of the claims were correct, I would agree that they disclose patentable subject matter. On the other hand, if the Court accepted my reading, I feel confident that the case would be decided differently.
There are three reasons why I cannot accept the Court’s conclusion that Diehr and Lutton claim to have discovered a new method of constantly measuring the temperature inside a mold. First, there is not a word in the patent application that suggests that there is anything unusual about the temperature-reading devices used in this process — or indeed that any particular species of temperature-reading device should be used in it.28 Second, since devices for constantly *208measuring actual temperatures — on a back porch, for example — have been familiar articles for quite some time, I find it difficult to believe that a patent application filed in 1975 was premised on the notion that a “process of constantly measuring the actual temperature” had just been discovered. Finally, the Patent and Trademark Office Board of Appeals expressly found that “the only difference between the conventional methods of operating a molding press and that claimed in [the] application rests in those steps of the claims which relate to the calculation incident to the solution of the mathematical problem or formula used to control the mold heater and the automatic opening of the press.”29 This finding was not disturbed by the Court of Customs and Patent Appeals and is clearly correct.
A fair reading of the entire patent application, as well as the specific claims, makes it perfectly clear that what Diehr and Lutton claim to have discovered is a method of using a digital computer to determine the amount of time that a rubber molding press should remain closed during the synthetic rubber-curing process. There is no suggestion that there is anything novel in the instrumentation of the mold, in actuating a timer when the press is closed, or in automatically opening the press when the computed time expires.30 Nor does the *209application suggest that Diehr and Lutton have discovered anything about the temperatures in the mold or the amount of curing time that will produce the best cure. What they claim to have discovered, in essence, is a method of updating the original estimated curing time by repetitively recalculating that time pursuant to a well-known mathematical formula in response to variations in temperature within the mold. Their method of updating the curing time calculation is strikingly reminiscent of the method of updating alarm limits that Dale Flook sought to patent.
Parker v. Flook, 437 U. S. 584 (1978), involved the use of a digital computer in connection with a catalytic conversion process. During the conversion process, variables such as temperature, pressure, and flow rates were constantly monitored and fed into the computer; in this case, temperature in the mold is the variable that is monitored and fed into the computer. In Flook, the digital computer repetitively recalculated the “alarm limit” — a number that might signal the need to terminate or modify the catalytic conversion process; in this case, the digital computer repetitively recalculates the correct curing time — a number that signals the time when the synthetic rubber molding press should open.
The essence of the claimed discovery in both cases was an algorithm that could be programmed on a digital computer.31 *210In Flook, the algorithm made use of multiple process variables; in this case, it makes use of only one. In Flook, the algorithm was expressed in a newly developed mathematical formula; in this case, the algorithm makes use of a well-known mathematical formula. Manifestly, neither of these differences can explain today’s holding.32 What I believe *211does explain today’s holding is a misunderstanding of the applicants’ claimed invention and a failure to recognize the critical difference between the “discovery” requirement in § 101 and the “novelty” requirement in § 102.33
Ill
The Court misapplies Parker v. Flook because, like the Court of Customs and Patent Appeals, it fails to understand or completely disregards the distinction between the subject matter of what the inventor claims to have discovered — the § 101 issue — and the question whether that claimed discovery is in fact novel — the § 102 issue.34 If there is not even a *212claim that anything constituting patentable subject matter has been discovered, there is no occasion to address the novelty issue.35 Or, as was true in Flook, if the only concept that the inventor claims to have discovered is not patentable subject matter, § 101 requires that the application be rejected without reaching any issue under § 102; for it is irrelevant that unpatentable subject matter — in that case a formula for updating alarm limits — may in fact be novel.
Proper analysis, therefore, must start with an understanding of what the inventor claims to have discovered — or phrased somewhat differently — what he considers his inventive concept to be.36 It seems clear to me that Diehr and *213Lutton claim to have developed a new method of programming a digital computer in order to calculate — promptly and repeatedly — the correct curing time in a familiar process.37 In the § 101 analysis, we must assume that the sequence of steps in this programming method is novel, unobvious, and useful. The threshold question of whether such a method is patentable subject matter remains.
If that method is regarded as an “algorithm” as that term was used in Gottschalk v. Benson, 409 U. S. 63 (1972), and in *214Parker v. Flook, 437 U. S. 584 (1978),38 and if no other inventive concept is disclosed in the patent application, the question must be answered in the negative. In both Benson and Flook, the parties apparently agreed that the inventor’s discovery was properly regarded as an algorithm; the holding that an algorithm was a “law of nature” that could not be *215patented therefore determined that those discoveries were not patentable processes within the meaning of § 101.
As the Court recognizes today, Flook also rejected the argument that patent protection was available if the inventor did not claim a monopoly on every conceivable use of the algorithm but instead limited his claims by describing a specific postsolution activity — in that case setting off an alarm in a catalytic conversion process. In its effort to distinguish Flook from the instant case, the Court characterizes that postsolution activity as “insignificant,” ante, at 191, or as merely “token” activity, ante, at 192, n. 14. As a practical matter, however, the postsolution activity described in the Flook application was no less significant than the automatic opening of the curing mold involved in this case. For setting off an alarm limit at the appropriate time is surely as important to the safe and efficient operation of a catalytic conversion process as is actuating the mold-opening device in a synthetic rubber-curing process. In both cases, the post-solution activity is a significant part of the industrial process. But in neither case should that activity have any legal significance because it does not constitute a part of the inventive concept that the applicants claimed to have discovered.39
In Gottschalk v. Benson, we held that a program for the *216solution by a digital computer of a mathematical problem was not a patentable process within the meaning of § 101. In Parker v. Flook, we further held that such a computer program could not be transformed into a patentable process by the addition of postsolution activity that was not claimed to be novel. That holding plainly requires the rejection of Claims 1 and 2 of the Diehr and Lutton application quoted in the Court’s opinion. Ante, at 179-180, n. 5. In my opinion, it equally requires rejection of Claim 11 because the presolution activity described in that claim is admittedly a familiar part of the prior art.40
Even the Court does not suggest that the computer program developed by Diehr and Lutton is a patentable discovery. Accordingly, if we treat the program as though it were a familiar part of the prior art — as well-established precedent requires41 — it is absolutely clear that their application contains no claim of patentable invention. Their application was therefore properly rejected under § 101 by the Patent Office and the Board of Appeals.
IV
The broad question whether computer programs should be given patent protection involves policy considerations that *217this Court is not authorized to address. See Gottschalk v. Benson, 409 U. S., at 72-73; Parker v. Flook, 437 U. S., at 595-596. As the numerous briefs amicus curiae filed in Gottschalk v. Benson, supra, Dann v. Johnston, 425 U. S. 219 (1976), Parker v. Flook, supra, and this case demonstrate, that question is not only difficult and important, but apparently also one that may be affected by institutional bias. In each of those cases, the spokesmen for the organized patent bar have uniformly favored patentability and industry representatives have taken positions properly motivated by their economic self-interest. Notwithstanding fervent argument that patent protection is essential for the growth of the software industry,42 commentators have noted that “this industry is growing by leaps and bounds without it.”43 In addition, even *218some commentators who believe that legal protection for computer programs is desirable have expressed doubts that the present patent system can provide the needed protection.44
Within the Federal Government, patterns of decision have also emerged. Gottschalk, Dann, Parker, and Diamond were not ordinary litigants — each was serving as Commissioner of Patents and Trademarks when he opposed the availability of patent protection for a program-related invention. No doubt each may have been motivated by a concern about the ability of the Patent Office to process effectively the flood of applications that would inevitably, flow from a decision that computer programs are patentable.45 The consistent concern evidenced by the Commissioner of Patents and Trademarks and by the Board of Appeals of the Patent and Trademark Office has not been shared by the Court of Customs and Patent Appeals, which reversed the Board in Benson, Johnston, and Flook, and was in turn reversed by this Court in each of those cases.46
*219Scholars have been critical of the work of both tribunals. Some of that criticism may stem from a conviction about the merits of the broad underlying policy question; such criticism may be put to one side. Other criticism, however, identifies two concerns to which federal judges have a duty to respond. First, the cases considering the patentability of program-related inventions do not establish rules that enable a conscientious patent lawyer to determine with a fair degree of accuracy which, if any, program-related inventions will be patentable. Second, the inclusion of the ambiguous concept of an “algorithm” within the “law of nature” category of unpatentable subject matter has given rise to the concern that almost any process might be so described and therefore held unpatentable.
In my judgment, today’s decision will aggravate the first concern and will not adequately allay the second. I believe both concerns would be better addressed by (1) an unequivocal holding that no program-related invention is a patentable process under § 101 unless it makes a contribution to the art that is not dependent entirely on the utilization of a computer, and (2) an unequivocal explanation that the term “algorithm” as used in this case, as in Benson and Flook, is synonymous with the term “computer program.”47 Because *220the invention claimed in the patent application at issue in this case makes no contribution to the art that is not entirely dependent upon the utilization of a computer in a familiar process, I would reverse the decision of the Court of Customs and Patent Appeals.
ENIAC, the first general purpose electronic digital computer, was built in 1946. Unlike modem computers, this machine was externally programmed; its circuitry had to be manually rewired each time it was used to perform a new task. See Gemignani, Legal Protection for Computer Software: The View From 79, 7 Rutgers J. Computers, Tech. & L. 269, 270 (1980). In 1952, a group of scientists at the Institute for Advanced Study completed MANIAC I, the first digital computer capable of operating upon stored programs, as opposed to hard-wired circuitry. See Ulam, Computers, 211 Scientific American 203 (1964).
In re Prater, 56 C. C. P. A. (Pat.) 1360, 415 F. 2d 1378 (1968), modified on rehearing, 56 C. C. P. A. (Pat.) 1381, 415 F. 2d 1393 (1969), is generally identified as the first significant judicial decision to consider the subject-matter patentability of computer program-related inventions. The Court of Customs and Patent Appeals earlier decided In re Naquin, 55 C. C. P. A. (Pat.) 1428, 398 F. 2d 863 (1968), in which it rejected a challenge to an application for a patent on a program-related invention on grounds of inadequate disclosure under § 112.
See Gottschalk v. Benson, 409 U. S. 63 (1972).
See also Novick & Wallenstein, The Algorithm and Computer Software Patentability: A Scientific View of a Legal Problem, 7 Rutgers J. Computers, Tech. & L. 313, 316-317 (1980).
See, e. g., Don Lee, Inc. v. Walker, 61 F. 2d 58, 67 (CA9 1932); In re Bolongaro, 20 C. C. P. A. (Pat.) 845, 846-847, 62 F. 2d 1059, 1060 (1933); In re Shao Wen Yuan, 38 C. C. P. A. (Pat.) 967, 969-972, 188 F. 2d 377, 379-380 (1951); Lyman v. Ladd, 120 U. S. App. D. C. 388, 389, 347 F. 2d 482, 483 (1965).
See, e. g., In re Cooper, 30 C. C. P. A. (Pat.) 946, 949, 134 F. 2d 630, 632 (1943); Halliburton Oil Well Cementing Co. v. Walker, 146 F. 2d 817, 821, 823 (CA9 1944), rev’d on other grounds, 329 U. S. 1 (1946); In re Heritage, 32 C. C. P. A. (Pat.) 1170, 1173-1177, 150 F. 2d 554, 556-558 (1945); In re Abrams, 38 C. C. P. A. (Pat.) 945, 950-953, 188 F. 2d 165, 168-170 (1951); In re Shao Wen Yuan, supra, at 975-976, 188 F. 2d, at 383; In re Lundberg, 39 C. C. P. A. (Pat.) 971, 975, 197 F. 2d 336, 339 (1952); In re Venner, 46 C. C. P. A. (Pat.) 754, 758-759, 262 F. 2d 91, 95 (1958).
The “function of a machine” doctrine is generally traced to Corning v. Burden, 15 How. 252, 268 (1854), in which the Court stated: “[I]t is well settled that a man cannot have a patent for the function or abstract effect of a machine, but only for the machine which produces it.” The doctrine was subsequently reaffirmed on several occasions. See, e. g., Risdon Iron & Locomotive Works v. Medart, 158 U. S. 68, 78-79, 84 (1895); Westinghouse v. Boyden Power Brake Co., 170 U. S. 537, 554-557 (1898); Busch v. Jones, 184 U. S. 598, 607 (1902); Expanded Metal Co. v. Bradford, 214 U. S. 366, 383 (1909).
See, e. g., In re Weston, 17 App. D. C. 431, 436-442 (1901); Chisholm-Ryder Co. v. Buck, 65 F. 2d 735, 736 (CA4 1933); In re Ernst, 21 C. C. P. A. (Pat.) 1235, 1238-1240, 71 F. 2d 169, 171-172 (1934); In re McCurdy, 22 C. C. P. A. (Pat.) 1140, 1142-1145, 76 F. 2d 400, 402-403, (1935); In re Parker, 23 C. C. P. A. (Pat.) 721, 722-725, 79 F. 2d 908, 909-910 (1935); Black-Clawson Co. v. Centrifugal Engineering & Patents Corp., 83 F. 2d 116, 119-120 (CA6), cert. denied, 299 U. S. 554 (1936); In re Wadman, 25 C. C. P. A. (Pat.) 936, 943-944, 94 F. 2d 993, 998 (1938); In re Mead, 29 C. C. P. A. (Pat.) 1001, 1004, 127 F. 2d 302, 304 (1942); In re Solakian, 33 C. C. P. A. (Pat.) 1054, 1059, 155 F. 2d 404, 407 (1946); In re Middleton, 35 C. C. P. A. (Pat.) 1166, 1167-1168, 167 F. 2d 1012, 1013-1014 (1948); In re Nichols, 36 C. C. P. A. (Pat.) 759, 762-763, 171 F. 2d 300, 302-303 (1948); In re Ashbaugh, 36 C. C. P. A. (Pat.) 902, 904-905, 173 F. 2d 273, 274-275 (1949); In re Horvath, 41 C. C. P. A. (Pat.) 844, 849-851, 211 F. 2d 604, 607-608 (1954); In re Gartner, 42 C. C. P. A. (Pat.) 1022, 1025-1026, 223 F. 2d 502, 504 (1955).
The Commission’s report contained the following evaluation of the current state of the law with respect to computer program patentability: “Uncertainty now exists as to whether the statute permits a valid patent to be granted on programs. Direct attempts to patent programs have been rejected on the ground of nonstatutory subject matter. Indirect attempts to obtain patents and avoid the rejection, by drafting claims as a process, or a machine or components thereof programmed in a given manner, rather than as a program itself, have confused the issue further and should not be permitted.” Report of the President’s Commission on the Patent System, “To Promote the Progress of . . . Useful Arts” in an Age of Exploding Technology 14 (1966).
The Patent Office guidelines were based primarily upon the mental-steps doctrine and the Cochrane v. Deener, 94 U. S. 780 (1877), definition of “process.” See 829 Off. Gaz. Pat. Off. 865 (Aug. 16, 1966); 33 Fed. Reg. 15609 (1968).
Judge Kirkpatrick, joined by Chief Judge Worley, wrote a vigorous dissent objecting to the majority’s decision to abandon “a rule which is about as solidly established as any rule of the patent law.” 55 C. C. P. A. (Pat.), at 1457, 397 F. 2d, at 868. Unlike the majority, the dissenting judges did not consider the doctrine inequitable or silly, and they observed that it had functioned in a satisfactory manner in the past. Id., at 1457-1458, 397 F. 2d, at 869. In addition, they considered the doctrine to be so well established that it had been adopted by implication in the Patent Act of 1952. Id., at 1458, 397 F. 2d. at 869.
In Prater, the patent application claimed an improved method for processing spectrographic data. The method analyzed conventionally obtained data by using well-known equations. The inventors had discovered a particular mathematical characteristic of the equations which enabled them to select the specific subset of equations that would yield optimum results. The application disclosed an analog computer as the preferred embodiment of the invention, but indicated that a programmed digital computer could also be used. 56 C. C. P. A. (Pat.), at 1361-1363, 415 F. 2d, at 1379-1380. The Patent Office had rejected the process claims on a mental-steps theory because the only novel aspect of the claimed method was the discovery of an unpatentable mathematical principle. The apparatus claim was rejected essentially because, when the mathematical principle was assumed to be within the prior art, the claim disclosed no invention entitled to patent protection. Id., at 1364-1365, 1375, 415 F. 2d, at 1381, 1399.
It is interesting to note that the Court of Customs and Patent Appeals in the second Prater opinion expressly rejected the Patent Office’s procedure for analyzing the apparatus claim pursuant to which the mathematical principle was treated as though it were within the prior art. 56 C. C. P. A. (Pat.), at 1397, 415 F. 2d, at 1405-1406. This precise procedure, of course, was later employed by this Court in Parker v. Flook, 437 U. S. 584 (1978).
Under the “point of novelty” approach, if the novelty or advancement in the art claimed by the inventor resided solely in a step of the process embodying a mental operation or other unpatentable element, the claim was rejected under § 101 as being directed to nonstatutory subject matter. See Blumenthal & Riter, Statutory or Non-Statutory?: An Analysis of the Patentability of Computer Related Inventions, 62 J. Pat. Off. Soc. 454, 457, 461, 470 (1980).
The author of the second Prater opinion, Judge Baldwin, disagreed with the Musgrave “technological arts” standard for process claims. He described that standard as “a major and radical shift in this area of the law.” 57 C. C. P. A. (Pat.), at 1367, 431 F. 2d, at 893-894. As Judge Baldwin read the majority opinion, claims drawn solely to purely mental processes were now entitled to patent protection. Id., at 1369, 431 F. 2d, at 895-896. Judge Baldwin’s understanding of Musgrave seems to have been confirmed in In re Foster, 58 C. C. P. A. (Pat.) 1001, 1004-1005, 438 F. 2d 1011, 1014-1015 (1971).
In the interval between the two Benson decisions, the Court of Customs and Patent Appeals decided several cases in which it addressed the patentability of computer-related inventions. In In re McIlroy, 58 C. C. P. A. (Pat.) 1249, 442 F. 2d 1397 (1971), and In re Waldbaum, 59 C. C. P. A. (Pat.) 940, 457 F. 2d 997 (1972), the court relied primarily upon Musgrave and Benson. In In re Ghiron, 58 C. C. P. A. (Pat.) 1207, 442 F. 2d 985 (1971), the court reaffirmed Tarczy-Hornoch’s rejection of the “function of a machine” doctrine.
Although the Court did not discuss the mental-steps doctrine in Benson, some commentators have suggested that the Court implicitly relied upon the doctrine in that case. See, e. g., Davis, supra n. 2, at 14, and n. 92. Other commentators have observed that the Court’s analysis in Benson was entirely consistent with the mental-steps doctrine. See, e. g., Comment, Computer Program Classification: A Limitation on Program Patentability as a Process, 53 Or. L. Rev. 501, 517-518, n. 132 (1974).
The decision of the Court of Customs and Patent Appeals was reversed by this Court on other grounds in Dann v. Johnston, 425 U. S. 219 (1976).
In addition to interpreting Benson, the majority aiso maintained that Christensen, despite its point-of-novelty language, had not signalled a return to that form of claim analysis. 545 F. 2d, at 158. The court would reaffirm this proposition consistently thereafter. See, e. g., In re de Castelet, 562 F. 2d 1236, 1240 (1977); In re Richman, 563 F. 2d 1026, 1029-1030 (1977); In re Freeman, 573 F. 2d 1237, 1243-1244 (1978); In re Toma, 575 F. 2d 872, 876 (1978); In re Walter, 618 F. 2d 758, 766-767 (1980).
See also In re Deutsch, 553 F. 2d 689, 692-693 (CCPA 1977); In re Waldbaum, 559 F. 2d 611, 616-617 (CCPA 1977); In re de Castelet, supra, at 1243-1245.
This form of claim analysis did not originate with Flook. Rather, the Court derived it from the landmark decision of O’Reilly v. Morse, 15 How. 62, 115 (1854). In addition, this analysis is functionally the same as the point-of-novelty analysis used in conjunction with the mental-steps doctrine. In fact, the Patent Office in the past occasionally phrased its mental-steps rejections in essentially the terms later employed in Flook. See nn. 13-15, supra. See generally Comment, 35 U. S. C. 101 Claim Analysis — The Point of Novelty Approach, 62 J. Pat. Off. Soc. 521 (1980).
The Court of Customs and Patent Appeals suggested that the cause of this Court’s error was the argument presented by the Solicitor General in Flook. According to the majority, the Solicitor General’s briefs “badly, and with a seeming sense of purpose” confused the statutory requirements. *205596 F. 2d, at 962. The court went on to describe part of the Solicitor General’s argument in Flook as “subversive nonsense.” 596 F. 2d, at 963.
See, e. g., In re Johnson, 589 F. 2d 1070 (1978); In re Phillips, 608 F. 2d 879 (1979); In re Sherwood, 613 F. 2d 809 (1980), cert. pending, No. 79-1941.
In an opinion written over a century ago, the Court noted:
“A manufacturing process is clearly an art, within the meaning of the law. Goodyear’s patent was for a process, namely, the process of vulcanizing *206india-rubber by subjecting it to a high degree of heat when mixed with sulphur and a mineral salt.
“The mixing of certain substances together, or the heating of a substance to a certain temperature, is a process.” Tilghman v. Proctor, 102 U. S. 707, 722, 728 (1881).
See also Corning v. Burden, 15 How. 252, 267 (1854). Modern rubber curing methods apparently still are based in substantial part upon the concept discovered by Goodyear:
“Since the day 120 years ago when Goodyear first heated a mixture of rubber and sulphur on a domestic stove and so discovered vulcanisation, this action of heat and sulphur has remained the standard method of converting crude rubber, with all its limitations, into a commercially usable product, giving it the qualities of resistance to heat and cold in addition to considerable mechanical strength.
“Goodyear also conjured up the word ‘cure’ for vulcanisation, and this has become the recognised term in production circles.” Memagh, Practical Vulcanisation, in The Applied Science of Rubber 1053 (W. Naunton ed. 1961).
See generally Kimmich, Making Rubber Products for Engineering Uses, in Engineering Uses of Rubber 18, 28-34 (A. McPherson & A. Klemin eds. 1956)
“Respondents characterize their contribution to the art to reside in the process of constantly measuring the actual temperature inside the mold.” See ante, at 178.
Claim 1 is quoted in full in n. 5 of the Court’s opinion, ante, at 179. It describes a “method of operating a rubber-molding press for precision molded compounds with the aid of a digital computer.” As the Court of Customs and Patent Appeals noted, the improvement claimed in the application consists of “opening the mold at precisely the correct time rather than at a time which has been determined by approximation or guesswork.” In re Diehr, 602 F. 2d 982, 988 (1979).
In the portion of the patent application entitled “Abstract of the Disclosure,” the following reference to monitoring the temperature is found:
“An interval timer starts running from the time of mold closure, and the temperature within the mold cavity is measured often, typically every ten seconds. The temperature is fed to a computer . . . .” App. to Pet. for Cert. 38a.
In the portion of the application entitled “Background of the Invention,” the following statement is found:
“By accurate and constant calculation and recalculation of the correct mold time under the temperatures actually present in the mold, the material can be cured accurately and can be relied upon to produce very few rejections, perhaps completely eliminating all rejections due to faulty mold cure.” Id., at 41a.
And, in the “Summary of the Invention,” this statement appears:
“A surveillance system is maintained over the mold to determine the actual mold temperature substantially continuously, for example, every *208ten seconds, and to feed that information to the computer along with the pertinent stored data and along with the elapsed time information.” Ibid. Finally, in a description of a simple hypothetical application using the invention described in Claim 1, this is the reference to the temperature-reading device:
“Thermocouples, or other temperature-detecting devices, located directly within the mold cavity may read the temperature at the surface where the molding compound touches the mold, so that it actually gets the temperature of the material at that surface.” Id., at 45a.
Id., at 24a.
These elements of the rubber-curing process apparently have been well known for years. The following description of the vulcanization process appears in a text published in 1961:
“Vulcanisation is too important an operation to be left to human control, however experienced and conscientious. Instrumentation makes controlled *209cure possible, and in consequence instrument engineering is a highly important function in the modern rubber factory, skilled attention being necessary, not only in the maintenance of the instruments but also in their siting. There are instruments available which will indicate, record or control all the services involved in vulcanisation, including time, temperature and pressure, and are capable of setting in motion such operations as the opening and closing of moulds and, in general, will control any process variable which is capable of being converted into an electric charge or pneumatic or hydraulic pressure impulse.” Mernagh, supra n. 25, at 1091-1092.
Commentators critical of the Flook decision have noted the essential similarity of the two inventions:
“The Diehr invention improved the control system by continually re*210measuring the temperature and recalculating the proper cure time. The computer would simultaneously keep track of the elapsed time. When the elapsed time equalled the proper cure time, the rubber would be released automatically from the mold.
“The facts are difficult to distinguish from those in Flook. Both processes involved (1) an initial calculation, (2) continual remeasurement and recalculation, and (3) some control use of the value obtained from the calculation.” Novick & Wallenstein, supra n. 5, at 326 (footnotes omitted).
Indeed, the most significant distinction between the invention at issue in Flook and that at issue in this case lies not in the characteristics of the inventions themselves, but rather in the drafting of the claims. After noting that “[t]he Diehr claims are reminiscent of the claims in Flook,” Blumenthal & Riter, supra n. 15, at 502-503 (footnote omitted), the authors of a recent article on the subject observe that the Court of Customs and Patent Appeals’ analysis in this ease “lends itself to an interesting exercise in claim drafting.” Id., at 505. To illustrate their point, the authors redrafted the Diehr and Lutton claims into the format employed in the Flook application:
“An improved method of calculating the cure time of a rubber molding process utilizing a digital computer comprising the steps of:
“a. inputting into said computer input values including
“1. natural logarithm conversion data ([l]n),
“2. an activation energy constant (C) unique to each batch of rubber being molded,
“3. a constant (X) dependent upon the geometry of the particular mold of the press, and
“4. continuous temperature values (Z) of the mold during molding;
“b. operating said computer for
“1. counting the elapsed cure time,
“2. calculating the cure time from the input values using the Arrhenius equation [l]n V=CZ+X, where V is the total cure time, and
*211“c. providing output signals from said computer when said calculated cure time is equal to said elapsed cure time.” Ibid.
The authors correctly conclude that even the lower court probably would have found that this claim was drawn to unpatentable subject matter under § 101. Id., at 505-506.
In addition to confusing the requirements of §§ 101 and 102, the Court also misapprehends the record in this case when it suggests that the Diehr and Lutton patent application may later be challenged for failure to satisfy the requirements of §§ 102 and 103. See ante, at 191. This suggestion disregards the fact that the applicants overcame all objections to issuance of the patent except the objection predicated on § 101. The Court seems to assume that §§ 102 and 103 issues of novelty and obviousness remain open on remand. As I understand the record, however, those issues have already been resolved. See Brief for Respondents 11-14; Reply Memorandum for Petitioner 3-4, and n. 4. Therefore, the Court is now deciding that the patent will issue.
The early cases that the Court of Customs and Patent Appeals refused to follow in Prater, Musgrave, and Benson had recognized the distinction between the § 101 requirement that what the applicant claims to have invented must be patentable subject matter and the § 102 requirement that the invention must actually be novel. See, e. g., In re Shao Wen Yuan, 38 C. C. P. A. (Pat.), at 973-976, 188 F. 2d, at 382-383; In re Abrams, 38 C. C. P. A. (Pat.), at 951-952, 188 F. 2d, at 169; In re Heritage, 32 C. C. P. A. (Pat.), at 1173-1174, 1176-1177, 150 F. 2d, at 556, 558; Halliburton Oil Well Cementing Co. v. Walker, 146 F. 2d, at 821, 823. The lower court’s error in this case, and its unenthusiastic reception of Gottschalk v. Benson and Parker v. Flook, is, of course, con*212sistent with its expansive reading of § 101 in Tarczy-Hornoch, Prater, and their progeny.
The Court’s opinion in Flook itself pointed out this distinction: “The obligation to determine what type of discovery is sought to be patented must precede the determination of whether that discovery is, in fact, new or obvious.” 437 U. S., at 593.
As the Court of Customs and Patent Appeals noted in this case, “for the claim to be statutory, there must be some substance to it other than the recitation and solution of the equation or formula.” 602 F. 2d, at 988. See Comment, 62 J. Pat. Off. Soc., supra n. 22, at 522-523.
The Court fails to focus upon what Diehr and Lutton claim to have discovered apparently because it believes that this method of analysis would improperly import novelty considerations into § 101. See ante, at 188-191, 193, n. 15. Rather than directing its attention to the applicants’ claimed discovery, the Court instead focuses upon the general industrial context in which the applicants intend their discovery to be used. Implicit in this interpretation of the patent application is the assumption that, as long as the claims describe a specific implication of the applicants’ discovery, patentable subject matter is defined. This assumption was expressly rejected in Flook:
“This assumption is based on respondent’s narrow reading of Benson, and is as untenable in the context of § 101 as it is in the context of that case. It would make the determination of patentable subject matter depend simply on the draftsman’s art and would ill serve the principles underlying the prohibition against patents for 'ideas' or phenomena of nature. The rule that the discovery of a law of nature cannot be pat*213ented rests, not on the notion that natural phenomena are not processes, but rather on the more fundamental understanding that they are not the kind of ‘discoveries’ that the statute was enacted to protect.” 437 U. S., at 593 (footnote omitted).
A few excerpts from the original patent application will emphasize this point:
“The invention will probably best be understood by first describing a simple example, in which a single mold is involved and in which the information is relatively static.
“A standard digital computer may be employed in this method. It has a data storage bank of suitable size which, of course, may vary when many molds are used and when more refinements are employed. However, Fig. 1 shows a relatively simple case which achieves results that are vast improvements over what has been done up to now. . . .
“The data bank of the computer is provided with a digital input into which the time-temperature cure data for the compound involved is fed, as shown in Fig. 1. AE the data is available to the computer upon caE, by random access, and the call can be automatic depending upon the temperature actually involved. In other words, the computer over and over questions the data storage, asking, what is the proper time of cure for the foEowing summation of temperatures? The question may be asked each second, and the answer is readily provided.
“Recalculation continues until the time that has elapsed since mold closure corresponds with the calculated time. Then, the computer actuates the mold-opening device and the mold is automatically opened.” App. to Pet. for Cert. 43a-45a.
*214The Figure 1 referred to in the application is as follows:
Id., at 53a.
In Benson, we explained the term “algorithm” in the following paragraph:
“The patent sought is on a method of programming a general-purpose digital computer to convert signals from binary-coded decimal form into pure binary form. 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.” 409 U. S., at 65.
In Flook, the Court’s analysis of the postsolution activity recited in the patent application turned, not on the relative significance of that activity in the catalytic conversion process, but rather on the fact that that activity was not a part of the applicant’s discovery:
“The notion that post-solution activity, no matter how conventional or obvious in itself, can transform an unpatentable principle into a patentable process exalts form over substance. A competent draftsman could attach some form of post-solution activity to almost any mathematical formula; the Pythagorean theorem would not have been patentable, or partially patentable, because a patent application contained a final step indicating that the formula-, when solved, could be usefully applied to existing surveying techniques. The concept of patentable subject matter under § 101 is not ‘like a nose of wax which may be turned and twisted in any direction . . . .’ White v. Dunbar, 119 U. S. 47, 51.” 437 U. S., at 590 (footnote omitted).
Although the Court of Customs and Patent Appeals erred because it ignored the distinction between the § 101 requirement that the applicant must claim to have discovered a novel process and the § 102 requirement that the discovery must actually be novel, that court correctly rejected the argument that any difference between Claim 11 and the earlier claims was relevant to the § 101 inquiry. See 602 F. 2d, at 984, 987-988.
This well-established precedent was reviewed in Parker v. Flook:
“Mackay Radio and Funk Bros, point to the proper analysis for this case: The process itself, not merely the mathematical algorithm, must be new and useful. Indeed, the novelty of the mathematical algorithm is not a determining factor at all. Whether the algorithm was in fact known or unknown at the time of the claimed invention, as one of the 'basic tools of scientific and technological work/ see Gottschalk v. Benson, 409 U. S., at 67, it is treated as though it were a familiar part of the prior art.” 437 U. S., at 591-592.
For example, the Association of Data Processing Service Organizations, appearing as amicus curiae in Flook, made the following policy argument:
“The need of the incentive of patents for software is at least as great as that of the incentive available for hardware, because: ‘Today, providing computer software involves greater . . . risk than providing computer . . . hardware. . . .’
“To a financial giant, the economic value of a patent may not loom large; to the small software products companies upon which the future of the development of quality software depends, the value of the patent in financing a small company may spell the difference between life and death. To banks and financial institutions the existence of a patent or even the potentiality of obtaining one may well be a decisive factor in determining whether a loan should be granted. To prospective investors a patent or the possibility of obtaining one may be the principal element in the decision whether to invest.
“Making clear that patents may be available for inventions in software would unleash important innovative talent. It would have the direct opposite effect forecast by the . . . hardware manufacturers; it would enable competition with those companies and provide the needed incentive to stimulate innovation.” Brief for ADAPSO as Amicus Curiae in Parker v. Flook, O. T. 1977, No. 77-642, p. 44 (footnote omitted).
Gemignani, supra n. 1, at 309. In a footnote to that comment, Professor Gemignani added that the rate of growth of the software industry *218“has been even faster lately than that of the hardware industry which does enjoy patent protections.” Id., at 309, n. 259. Other commentators are in accord. See Nycum, Legal Protection for Computer Programs, 1 Computer L. J. 1, 55-58 (1978); Note, Protection of Computer Programs: Resurrection of the Standard, 50 Notre Dame Law. 333, 344 (1974).
See, e. g., Gemignani, supra n. 1, at 301-312; Keefe & Mahn, Protecting Software: Is It Worth All the Trouble?, 62 A. B. A. J. 906, 907 (1976).
This concern influenced the President’s Commission on the Patent System when it recommended against patent protection for computer programs. In its report, the President’s Commission stated:
“The Patent Office now cannot examine applications for programs because of the lack of a classification technique and the requisite search files. Even if these were available, reliable searches would not be feasible or economic because of the tremendous volume of prior art being generated. Without this search, the patenting of programs would be tantamount to mere registration and the presumption of validity would be all but nonexistent.” Report of the President’s Commission, supra n. 10, at 13.
It is noteworthy that the position of the Court of Customs and Patent Appeals in the process patent area had been consistent with that *219cf the Commissioner of Patents and Trademarks for decades prior to 1968. As discussed in Part I, supra, in that year the court rejected two longstanding doctrines that would have foreclosed patentability for most computer programs under § 101.
A number of authorities have drawn the conclusion that the terms are in fact synonymous. See, e. g., Novick & Wallenstein, supra n. 5, at 333, n. 172; Anderson, Algorithm, 1 Encyclopedia of Computer Science & Technology 364, 369 (J. Belzer, A. Holzman & A. Kent eds. 1975); E. Horowitz & S. Sahni, Fundamentals of Computer Algorithms 2 (1978); A. Tanenbaum, Structured Computer Organization 10 (1976). Cf. Blumenthal & Riter, supra n. 15, at 455-456; Gemignani, supra n. 1, at 271-273, 276, n. 37.