with whom Mr. Justice White, Mr. Justice Marshall, and Mr. Justice Powell join, dissenting.
I agree with the Court that the question before us is a narrow one. Neither the future of scientific research, nor even the ability of respondent Chakrabarty to reap some monopoly profits from his pioneering work, is at stake. Patents on the processes by which he has produced and employed the new living organism are not contested. The only question we need decide is whether Congress, exercising its authority under Art. I, § 8, of the Constitution, intended that he be able to secure a monopoly on the living organism itself, no matter how produced or how used. Because I believe the Court has misread the applicable legislation, I dissent.
*319The patent laws attempt to reconcile this Nation’s deep-seated antipathy to monopolies with the need to encourage progress. Deepsouth Packing Co. v. Laitram Corp., 406 U. S. 518, 530-531 (1972); Graham v. John Deere Co., 383 U. S. 1, 7-10 (1966). Given the complexity and legislative nature of this delicate task, we must be careful to extend patent protection no further than Congress has provided. In particular, were there an absence of legislative direction, the courts should leave to Congress the decisions whether and how far to extend the patent privilege into areas where the common understanding has been that patents are not available.1 Cf. Deepsouth Packing Co. v. Laitram Corp., supra.
In this case, however, we do not confront a complete legislative vacuum. The sweeping language of the Patent Act of 1793, as re-enacted in 1952, is not the last pronouncement Congress has made in this area. In 1930 Congress enacted the Plant Patent Act affording patent protection to developers of certain asexually reproduced plants. In 1970 Congress enacted the Plant Variety Protection Act to extend protection to certain new plant varieties capable of sexual reproduction. Thus, we are not dealing — as the Court would have it — with the routine problem of “unanticipated inventions.” Ante, at 316. In these two Acts Congress has addressed the general problem of patenting animate inventions and has chosen carefully limited language granting protection to some kinds of discoveries, but specifically excluding others. These Acts strongly evidence a congressional limitation that excludes bacteria from patentability.2
*320First, the Acts evidence Congress’ understanding, at least since 1930, that § 101 does not include living organisms. If newly developed living organisms not naturally occurring had been patentable under § 101, the plants included in the scope of the 1930 and 1970 Acts could have been patented without new legislation. Those plants, like the bacteria involved in this case, were new varieties not naturally occurring.3 Although the Court, ante, at 311, rejects this line of argument, it does not explain why the Acts were necessary unless to correct a pre-existing situation.4 I cannot share the Court’s implicit assumption that Congress was engaged in either idle exercises or mere correction of the public record when it enacted the 1930 and 1970 Acts. And Congress certainly thought it was doing something significant. The Committee Reports contain expansive prose about the previously unavailable benefits to be derived from extending patent protection to plants.5 H. R. *321Rep. No. 91-1605, pp. 1-3 (1970); S. Rep. No. 315, 71st Cong., 2d Sess., 1-3 (1930). Because Congress thought it had to legislate in order to make agricultural “human-made inventions” patentable and because the legislation Congress enacted is limited, it follows that Congress never meant to make items outside the scope of the legislation patentable.
Second, the 1970 Act clearly indicates that Congress has included bacteria within the focus of its legislative concern, but not within the scope of patent protection. Congress specifically excluded bacteria from the coverage of the 1970 Act. 7 U. S. C. § 2402 (a). The Court’s attempts to supply explanations for this explicit exclusion ring hollow. It is true that there is no mention in the legislative history of the exclusion, but that does not give us license to invent reasons. The fact is that Congress, assuming that animate objects as to which it had not specifically legislated could not be patented, excluded bacteria from the set of patentable organisms.
The Court protests that its holding today is dictated by the broad language of § 101, which cannot “be confined to the ‘particular application [s] . . . contemplated by the legislators.’ ” Ante, at 315, quoting Barr v. United States, 324 U. S. 83, 90 (1945). But as I have shown, the Court’s decision does not follow the unavoidable implications of the statute. Rather, it extends the patent system to cover living material *322even though Congress plainly has-legislated in the belief that § 101 does not encompass living organisms. It is the role of Congress, not this Court, to broaden or narrow the reach of the patent laws. This is especially true where, as here, the composition sought to be patented uniquely implicates matters of public concern.
I read the Court to admit that the popular conception, even among advocates of agricultural patents, was that living organisms were unpatentable. See ante, a.t 311-312, and n. 8.
But even if I agreed with the Court that the 1930 and 1970 Acts were not dispositive, I would dissent. This case presents even more cogent reasons than Deepsouth Packing Co. not to extend the patent monopoly in the face of uncertainty. At the very least, these Acts are signs of legislative attention to the problems of patenting living organisms, but they give *320no affirmative indication of congressional intent that bacteria be patentable. The caveat of Parker v. Flook, 437 U. S. 584, 596 (1978), an admonition to “proceed cautiously when we are asked to extend patent rights into areas wholly unforeseen by Congress,” therefore becomes pertinent. I should think the necessity for caution is that much greater when we are asked to extend patent rights into areas Congress has foreseen and considered but has not resolved.
The Court refers to the logic employed by Congress in choosing not to perpetuate the “dichotomy” suggested by Secretary Hyde. Ante, at 313. But by this logic the bacteria at issue here are distinguishable from a “mineral . . . created wholly by nature” in exactly the same way as were the new varieties of plants. If a new Act was needed to provide patent protection for the plants, it was equally necessary for bacteria. Yet Congress provided for patents on plants but not on these bacteria. In short, Congress decided to make only a subset of animate “human-made inventions,” ibid., patentable.
If the 1930 Act’s only purpose were to solve the technical problem of description referred to by the Court, ante, at 312, most of the Act, and in particular its limitation to asexually reproduced plants, would have been totally unnecessary.
Secretary Hyde’s letter was not the only explicit indication in the legislative history of these Acts that Congress was acting on the assumption *321that legislation was necessary to make living organisms patentable. The Senate Judiciary Committee Report on the 1970 Act states the Committee’s understanding that patent protection extended no further than the explicit provisions of these Acts:
“Under the patent law, patent protection is limited to those varieties of plants which reproduce asexually, that is, by such methods as grafting or budding. No protection is available to those varieties of plants which reproduce sexually, that is, generally by seeds.” S. Rep. No. 91-1246, p. 3 (1970).
Similarly, Representative Poage, speaking for the 1970 Act, after noting the protection accorded asexually developed plants, stated that “for plants produced from seed, there has been no such protection.” 116 Cong. Rec. 40295 (1970).