(Slip Opinion)              OCTOBER TERM, 2010                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

   MICROSOFT CORP. v. I4I LIMITED PARTNERSHIP 

                      ET AL. 


CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                THE FEDERAL CIRCUIT

       No. 10–290.      Argued April 18, 2011—Decided June 9, 2011
In asserting patent invalidity as a defense to an infringement action, an
  alleged infringer must contend with §282 of the Patent Act of 1952
  (Act), under which “[a] patent shall be presumed valid” and “[t]he
  burden of establishing invalidity . . . shall rest on the party asserting”
  it. Since 1984, the Federal Circuit has read §282 to require a defen
  dant seeking to overcome the presumption to persuade the factfinder
  of its invalidity defense by clear and convincing evidence.
     Respondents (collectively, i4i) hold the patent at issue, which
  claims an improved method for editing computer documents. After
  i4i sued petitioner Microsoft Corp. for willful infringement of that
  patent, Microsoft counterclaimed and sought a declaration that the
  patent was invalid under §102(b)’s on-sale bar, which precludes pat
  ent protection for any “invention” that was “on sale in this country”
  more than one year prior to the filing of a patent application. The
  parties agreed that, more than a year before filing its patent applica
  tion, i4i had sold a software program known as S4 in the United
  States, but they disagreed over whether that software embodied the
  invention claimed in i4i’s patent. Relying on the undisputed fact that
  the S4 software was never presented to the Patent and Trademark
  Office (PTO) during its examination of the patent application, Micro
  soft objected to i4i’s proposed jury instruction that the invalidity de
  fense must be proved by clear and convincing evidence. The District
  Court nevertheless gave that instruction, rejecting Microsoft’s alter
  native instruction proposing a preponderance of the evidence stan
  dard. The jury found that Microsoft willfully infringed the i4i patent
  and had failed to prove the patent’s invalidity. The Federal Circuit
  affirmed, relying on its settled interpretation of §282.
2          MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                                Syllabus

Held: Section 282 requires an invalidity defense to be proved by clear
 and convincing evidence. Pp. 5–20.
    (a) The Court rejects Microsoft’s contention that a defendant need
 only persuade the jury of a patent invalidity defense by a preponder
 ance of the evidence. Where Congress has prescribed the governing
 standard of proof, its choice generally controls. Steadman v. SEC,
 450 U. S. 91, 95. Congress has made such a choice here. While §282
 includes no express articulation of the standard of proof, where Con
 gress uses a common-law term in a statute, the Court assumes the
 “term . . . comes with a common law meaning.” Safeco Ins. Co. of
 America v. Burr, 551 U. S. 47, 58. Here, by stating that a patent is
 “presumed valid,” §282, Congress used a term with a settled common
 law meaning. Radio Corp. of America v. Radio Engineering Labora
 tories, Inc., 293 U. S. 1 (RCA), is authoritative. There, tracing nearly
 a century of case law, the Court stated, inter alia, that “there is a
 presumption of [patent] validity [that is] not to be overthrown except
 by clear and cogent evidence,” id., at 2. Microsoft’s contention that
 the Court’s pre-Act precedents applied a clear-and-convincing stan
 dard only in two limited circumstances is unavailing, given the ab
 sence of those qualifications from the Court’s cases. Also unpersua
 sive is Microsoft’s argument that the Federal Circuit’s interpretation
 must fail because it renders superfluous §282’s additional statement
 that “[t]he burden of establishing invalidity . . . shall rest on the
 party asserting” it. The canon against superfluity assists only where
 a competing interpretation gives effect “ ‘to every clause and word of
 a statute.’ ” Duncan v. Walker, 533 U. S. 167, 174. Here, no inter
 pretation of §282 avoids excess language because, under either of Mi
 crosoft’s alternative theories—that the presumption only allocates
 the burden of production or that it shifts both the burdens of produc
 tion and persuasion—the presumption itself would be unnecessary in
 light of §282’s additional statement as to the challenger’s burden.
 Pp. 5–13.
    (b) Also rejected is Microsoft’s argument that a preponderance
 standard must at least apply where the evidence before the factfinder
 was not before the PTO during the examination process. It is true
 enough that, in these circumstances, “the rationale underlying the
 presumption—that the PTO, in its expertise, has approved the
 claim—seems much diminished,” KSR Int’l Co. v. Teleflex Inc., 550
 U. S. 398, 426, though other rationales may still animate the pre
 sumption. But the question remains whether Congress has specified
 the applicable standard of proof. As established here today, Congress
 did just that by codifying the common-law presumption of patent va
 lidity and, implicitly, the heightened standard of proof attached to it.
 The Court’s pre-Act cases never adopted or endorsed Microsoft’s fluc
                     Cite as: 564 U. S. ____ (2011)                      3

                                Syllabus

  tuating standard of proof. And they do not indicate, even in dicta,
  that anything less than a clear-and-convincing standard would ever
  apply to an invalidity defense. In fact, the Court indicated to the con
  trary. See RCA, 293 U. S., at 8. Finally, the Court often applied the
  heightened standard of proof without mentioning whether the rele
  vant prior-art evidence had been before the PTO examiner, in cir
  cumstances strongly suggesting it had not. See, e.g., Smith v. Hall,
  301 U. S. 216, 227, 233. Nothing in §282’s text suggests that Con
  gress meant to depart from that understanding to enact a standard of
  proof that would rise and fall with the facts of each case. Indeed, had
  Congress intended to drop the heightened standard of proof where
  the evidence before the jury varied from that before the PTO, it pre
  sumably would have said so expressly. Those pre-Act cases where
  various Courts of Appeals observed that the presumption is weak
  ened or dissipated where the evidence was never considered by the
  PTO should be read to reflect the commonsense principle that if the
  PTO did not have all material facts before it, its considered judgment
  may lose significant force. Cf. KSR, 550 U. S., at 427. Consistent
  with that principle, a jury may be instructed to evaluate whether the
  evidence before it is materially new, and if so, to consider that fact
  when determining whether an invalidity defense has been proved by
  clear and convincing evidence. Pp. 14–18.
     (c) This Court is in no position to judge the comparative force of the
  parties’ policy arguments as to the wisdom of the clear-and
  convincing-evidence standard that Congress adopted.            Congress
  specified the applicable standard of proof in 1952 when it codified the
  common-law presumption of patent validity. During the nearly 30
  years that the Federal Circuit has interpreted §282 as the Court does
  today, Congress has often amended §282 and other patent laws, but
  apparently has never considered any proposal to lower the standard
  of proof. Indeed, Congress has left the Federal Circuit’s interpreta
  tion in place despite ongoing criticism, both from within the Federal
  Government and without. Accordingly, any recalibration of the stan
  dard of proof remains in Congress’ hands. Pp. 18–20.
598 F. 3d 831, affirmed.

   SOTOMAYOR, J., delivered the opinion of the Court, in which SCALIA,
KENNEDY, GINSBURG, BREYER, ALITO, and KAGAN, JJ., joined. BREYER,
J., filed a concurring opinion, in which SCALIA and ALITO, JJ., joined.
THOMAS, J., filed an opinion concurring in the judgment. ROBERTS,
C. J., took no part in the consideration or decision of the case.
                        Cite as: 564 U. S. ____ (2011)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 10–290
                                   _________________


   MICROSOFT CORPORATION, PETITIONER v. i4i 

         LIMITED PARTNERSHIP ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

           APPEALS FOR THE FEDERAL CIRCUIT

                                 [June 9, 2011]


  JUSTICE SOTOMAYOR delivered the opinion of the Court.
  Under §282 of the Patent Act of 1952, “[a] patent shall
be presumed valid” and “[t]he burden of establishing in
validity of a patent or any claim thereof shall rest on the
party asserting such invalidity.” 35 U. S. C. §282. We
consider whether §282 requires an invalidity defense to be
proved by clear and convincing evidence. We hold that it
does.
                               I

                              A

  Pursuant to its authority under the Patent Clause, U. S.
Const., Art. I, §8, cl. 8, Congress has charged the United
States Patent and Trademark Office (PTO) with the task
of examining patent applications, 35 U. S. C. §2(a)(1), and
issuing patents if “it appears that the applicant is entitled
to a patent under the law,” §131. Congress has set forth
the prerequisites for issuance of a patent, which the PTO
must evaluate in the examination process. To receive
patent protection a claimed invention must, among other
things, fall within one of the express categories of pat
entable subject matter, §101, and be novel, §102, and
2        MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                     Opinion of the Court

nonobvious, §103. Most relevant here, the on-sale bar of
§102(b) precludes patent protection for any “invention”
that was “on sale in this country” more than one year prior
to the filing of a patent application. See generally Pfaff v.
Wells Electronics, Inc., 525 U. S. 55, 67–68 (1998). In
evaluating whether these and other statutory conditions
have been met, PTO examiners must make various factual
determinations—for instance, the state of the prior art in
the field and the nature of the advancement embodied in
the invention. See Dickinson v. Zurko, 527 U. S. 150, 153
(1999).
   Once issued, a patent grants certain exclusive rights to
its holder, including the exclusive right to use the inven
tion during the patent’s duration. To enforce that right, a
patentee can bring a civil action for infringement if an
other person “without authority makes, uses, offers to sell,
or sells any patented invention, within the United States.”
§271(a); see also §281.
   Among other defenses under §282 of the Patent Act of
1952 (1952 Act), an alleged infringer may assert the inva
lidity of the patent—that is, he may attempt to prove that
the patent never should have issued in the first place. See
§§282(2), (3). A defendant may argue, for instance, that
the claimed invention was obvious at the time and thus
that one of the conditions of patentability was lacking.
See §282(2); see also §103. “While the ultimate question of
patent validity is one of law,” Graham v. John Deere Co.
of Kansas City, 383 U. S. 1, 17 (1966) (citing Great Atlantic
& Pacific Tea Co. v. Supermarket Equipment Corp., 340
U. S. 147, 155 (1950) (Douglas, J., concurring)); see post,
at 1 (BREYER, J., concurring), the same factual questions
underlying the PTO’s original examination of a patent ap
plication will also bear on an invalidity defense in an in
fringement action. See, e.g., 383 U. S., at 17 (describing
the “basic factual inquiries” that form the “background”
for evaluating obviousness); Pfaff, 525 U. S., at 67–69
                    Cite as: 564 U. S. ____ (2011)                   3

                         Opinion of the Court

(same, as to the on-sale bar).
   In asserting an invalidity defense, an alleged infringer
must contend with the first paragraph of §282, which
provides that “[a] patent shall be presumed valid” and
“[t]he burden of establishing invalidity . . . rest[s] on the
party asserting such invalidity.”1 Under the Federal
Circuit’s reading of §282, a defendant seeking to overcome
this presumption must persuade the factfinder of its in
validity defense by clear and convincing evidence. Judge
Rich, a principal drafter of the 1952 Act, articulated this
view for the court in American Hoist & Derrick Co. v.
Sowa & Sons, Inc., 725 F. 2d 1350 (CA Fed. 1984). There,
the Federal Circuit held that §282 codified “the existing
presumption of validity of patents,” id., at 1359 (internal
quotation marks omitted)—what, until that point, had
been a common-law presumption based on “the basic
proposition that a government agency such as the [PTO]
was presumed to do its job,” ibid. Relying on this Court’s
pre-1952 precedent as to the “force of the presumption,”
ibid. (citing Radio Corp. of America v. Radio Engineering
Laboratories, Inc., 293 U. S. 1 (1934) (RCA)), Judge Rich
concluded:
     “[Section] 282 creates a presumption that a patent is
     valid and imposes the burden of proving invalidity on
     the attacker. That burden is constant and never
     changes and is to convince the court of invalidity by
     clear evidence.” 725 F. 2d, at 1360.
In the nearly 30 years since American Hoist, the Federal
Circuit has never wavered in this interpretation of §282.
See, e.g., Greenwood v. Hattori Seiko Co., 900 F. 2d 238,
——————
  1 As originally enacted in 1952, the first paragraph of §282 read: “A

patent shall be presumed valid. The burden of establishing invalidity
of a patent shall rest on a party asserting it.” 66 Stat. 812. Congress
has since amended §282, inserting two sentences not relevant here and
modifying the language of the second sentence to that in the text.
4        MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                      Opinion of the Court

240–241 (CA Fed. 1990); Ultra-Tex Surfaces, Inc. v. Hill
Bros. Chemical Co., 204 F. 3d 1360, 1367 (CA Fed. 2000);
ALZA Corp. v. Andrx Pharmaceuticals, LLC, 603 F. 3d
935, 940 (CA Fed. 2010).
                                B
   Respondents i4i Limited Partnership and Infrastruc
tures for Information Inc. (collectively, i4i) hold the patent
at issue in this suit. The i4i patent claims an improved
method for editing computer documents, which stores a
document’s content separately from the metacodes asso
ciated with the document’s structure. In 2007, i4i sued
petitioner Microsoft Corporation for willful infringement,
claiming that Microsoft’s manufacture and sale of certain
Microsoft Word products infringed i4i’s patent. In addi
tion to denying infringement, Microsoft counterclaimed
and sought a declaration that i4i’s patent was invalid and
unenforceable.
   Specifically and as relevant here, Microsoft claimed that
the on-sale bar of §102(b) rendered the patent invalid,
pointing to i4i’s prior sale of a software program known as
S4. The parties agreed that, more than one year prior to
the filing of the i4i patent application, i4i had sold S4
in the United States. They presented opposing arguments
to the jury, however, as to whether that software embod
ied the invention claimed in i4i’s patent. Because the
software’s source code had been destroyed years before the
commencement of this litigation, the factual dispute
turned largely on trial testimony by S4’s two inventors—
also the named inventors on the i4i patent—both of whom
testified that S4 did not practice the key invention dis
closed in the patent.
   Relying on the undisputed fact that the S4 software was
never presented to the PTO examiner, Microsoft objected
to i4i’s proposed instruction that it was required to prove
its invalidity defense by clear and convincing evidence.
                     Cite as: 564 U. S. ____ (2011)                   5

                         Opinion of the Court

Instead, “if an instruction on the ‘clear and convincing’
burden were [to be] given,” App. 124a, n. 8, Microsoft re
quested the following:
     “ ‘Microsoft’s burden of proving invalidity and unen
     forceability is by clear and convincing evidence. How
     ever, Microsoft’s burden of proof with regard to its
     defense of invalidity based on prior art that the ex
     aminer did not review during the prosecution of the
     patent-in-suit is by preponderance of the evidence.’ ”
     Ibid.
Rejecting the hybrid standard of proof that Microsoft
advocated, the District Court instructed the jury that
“Microsoft has the burden of proving invalidity by clear
and convincing evidence.” App. to Pet. for Cert. 195a.
   The jury found that Microsoft willfully infringed the i4i
patent and that Microsoft failed to prove invalidity due to
the on-sale bar or otherwise. Denying Microsoft’s post
trial motions, the District Court rejected Microsoft’s con
tention that the court improperly instructed the jury on
the standard of proof. The Court of Appeals for the Fed
eral Circuit affirmed.2 598 F. 3d 831, 848 (2010). Relying
on its settled interpretation of §282, the court explained
that it could “discern [no] error” in the jury instruction
requiring Microsoft to prove its invalidity defense by clear
and convincing evidence. Ibid. We granted certiorari.
562 U. S. ___ (2010).
                            II
  According to Microsoft, a defendant in an infringement
action need only persuade the jury of an invalidity defense
by a preponderance of the evidence. In the alternative,
Microsoft insists that a preponderance standard must
——————
   2 Although not relevant here, the Court of Appeals modified the effec

tive date of the permanent injunction that the District Court entered in
favor of i4i. 598 F. 3d 831, 863–864 (CA Fed. 2010).
6          MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                          Opinion of the Court

apply at least when an invalidity defense rests on evidence
that was never considered by the PTO in the examination
process. We reject both contentions.3
                              A
   Where Congress has prescribed the governing standard
of proof, its choice controls absent “countervailing consti
tutional constraints.” Steadman v. SEC, 450 U. S. 91, 95
(1981). The question, then, is whether Congress has made
such a choice here.
   As stated, the first paragraph of §282 provides that
“[a] patent shall be presumed valid” and “[t]he burden of
establishing invalidity of a patent or any claim thereof
shall rest on the party asserting such invalidity.” Thus, by
its express terms, §282 establishes a presumption of pat
ent validity, and it provides that a challenger must over
come that presumption to prevail on an invalidity defense.
But, while the statute explicitly specifies the burden of
proof, it includes no express articulation of the standard of
proof.4
——————
   3 i4i contends that Microsoft forfeited the first argument by failing to

raise it until its merits brief in this Court. The argument, however, is
within the scope of the question presented, and because we reject it on
its merits, we need not decide whether it has been preserved.
   4 A preliminary word on terminology is in order. As we have said,

“[t]he term ‘burden of proof’ is one of the ‘the slipperiest members of
the family of legal terms.’ ” Schaffer v. Weast, 546 U. S. 49, 56 (2005)
(quoting 2 J. Strong, McCormick on Evidence §342, p. 433 (5th ed.
1999) (alteration omitted)). Historically, the term has encompassed two
separate burdens: the “burden of persuasion” (specifying which party
loses if the evidence is balanced), as well as the “burden of production”
(specifying which party must come forward with evidence at various
stages in the litigation). Ibid. Adding more confusion, the term “bur
den of proof” has occasionally been used as a synonym for “standard of
proof.” E.g., Grogan v. Garner, 498 U. S. 279, 286 (1991).
   Here we use “burden of proof” interchangeably with “burden of per
suasion” to identify the party who must persuade the jury in its favor to
prevail. We use the term “standard of proof” to refer to the degree of
certainty by which the factfinder must be persuaded of a factual conclu
                      Cite as: 564 U. S. ____ (2011)                       7

                           Opinion of the Court

   Our statutory inquiry, however, cannot simply end
there. We begin, of course, with “the assumption that the
ordinary meaning of the language” chosen by Congress
“accurately expresses the legislative purpose.” Engine
Mfrs. Assn. v. South Coast Air Quality Management Dist.,
541 U. S. 246, 252 (2004) (internal quotation marks omit
ted). But where Congress uses a common-law term in a
statute, we assume the “term . . . comes with a common
law meaning, absent anything pointing another way.”
Safeco Ins. Co. of America v. Burr, 551 U. S. 47, 58 (2007)
(citing Beck v. Prupis, 529 U. S. 494, 500–501 (2000)).
Here, by stating that a patent is “presumed valid,” §282,
Congress used a term with a settled meaning in the com
mon law.
   Our decision in RCA, 293 U. S. 1, is authoritative.
There, tracing nearly a century of case law from this Court
and others, Justice Cardozo wrote for a unanimous Court
that “there is a presumption of validity, a presumption not
to be overthrown except by clear and cogent evidence.”
Id., at 2. Although the “force” of the presumption found
“varying expression” in this Court and elsewhere, id., at 7,
Justice Cardozo explained, one “common core of thought
and truth” unified the decisions:
     “[O]ne otherwise an infringer who assails the validity
     of a patent fair upon its face bears a heavy burden of
     persuasion, and fails unless his evidence has more
     than a dubious preponderance. If that is true where
—————— 

sion to find in favor of the party bearing the burden of persuasion. See 

Addington v. Texas, 441 U. S. 418, 423 (1979). In other words, the term

“standard of proof” specifies how difficult it will be for the party bearing 

the burden of persuasion to convince the jury of the facts in its favor. 

Various standards of proof are familiar—beyond a reasonable doubt, by

clear and convincing evidence, and by a preponderance of the evidence. 

See generally 21B C. Wright & K. Graham, Federal Practice & Proce
dure §5122, pp. 405–411 (2d ed. 2005) (hereinafter Fed. Practice)

(describing these and other standards of proof). 

8          MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                          Opinion of the Court

     the assailant connects himself in some way with the
     title of the true inventor, it is so a fortiori where he is
     a stranger to the invention, without claim of title of
     his own. If it is true where the assailant launches his
     attack with evidence different, at least in form, from
     any theretofore produced in opposition to the patent,
     it is so a bit more clearly where the evidence is
     even verbally the same.” Id., at 8 (internal citation
     omitted).5
The common-law presumption, in other words, reflected
the universal understanding that a preponderance stan
dard of proof was too “dubious” a basis to deem a patent
invalid. Ibid.; see also id., at 7 (“[A] patent . . . is pre
sumed to be valid until the presumption has been over
come by convincing evidence of error”).
  Thus, by the time Congress enacted §282 and declared
that a patent is “presumed valid,” the presumption of
patent validity had long been a fixture of the common law.
According to its settled meaning, a defendant raising an
invalidity defense bore “a heavy burden of persuasion,”
requiring proof of the defense by clear and convincing
evidence. Id., at 8. That is, the presumption encompassed
not only an allocation of the burden of proof but also an
imposition of a heightened standard of proof. Under the
——————
   5 Among other cases, Justice Cardozo cited Cantrell v. Wallick, 117

U. S. 689, 695–696 (1886) (“Not only is the burden of proof to make
good this defence upon the party setting it up, but . . . every reasonable
doubt should be resolved against him” (internal quotation marks
omitted)); Coffin v. Ogden, 18 Wall. 120, 124 (1874) (“The burden of
proof rests upon [the defendant], and every reasonable doubt should be
resolved against him”); The Barbed Wire Patent, 143 U. S. 275, 285
(1892) (“[This] principle has been repeatedly acted upon in the different
circuits”); and Washburn v. Gould, 29 F. Cas. 312, 320 (No. 17,214) (CC
Mass. 1844) (charging jury that “[i]f it should so happen, that your
minds are led to a reasonable doubt on the question, inasmuch as it is
incumbent on the defendant to satisfy you beyond that doubt, you will
find for the plaintiff”).
                 Cite as: 564 U. S. ____ (2011)            9

                     Opinion of the Court

general rule that a common-law term comes with its
common-law meaning, we cannot conclude that Congress
intended to “drop” the heightened standard proof from
the presumption simply because §282 fails to reiterate it
expressly. Neder v. United States, 527 U. S. 1, 23 (1999);
see also id., at 21 (“ ‘Where Congress uses terms that have
accumulated settled meaning under . . . the common law,
[we] must infer, unless the statute otherwise dictates, that
Congress means to incorporate the established meaning of
those terms.’ ” (quoting Nationwide Mut. Ins. Co. v. Dar
den, 503 U. S. 318, 322 (1992))); Standard Oil Co. of N. J.
v. United Sates, 221 U. S. 1, 59 (1911) (“[W]here words are
employed in a statute which had at the time a well-known
meaning at common law or in the law of this country they
are presumed to have been used in that sense . . .”). “On
the contrary, we must presume that Congress intended to
incorporate” the heightened standard of proof, “unless the
statute otherwise dictates.” Neder, 527 U. S., at 23 (inter
nal quotation marks omitted).
   We recognize that it may be unusual to treat a presump
tion as alone establishing the governing standard of proof.
See, e.g., J. Thayer, Preliminary Treatise on Evidence at
the Common Law 336–337 (1898) (hereinafter Thayer)
(“When . . . we read that the contrary of any particular
presumption must be proved beyond a reasonable doubt, . . .
it is to be recognized that we have something superadded
to the rule of presumption, namely, another rule as to
the amount of evidence which is needed to overcome the
presumption”). But given how judges, including Justice
Cardozo, repeatedly understood and explained the pre
sumption of patent validity, we cannot accept Microsoft’s
argument that Congress used the words “presumed valid”
to adopt only a procedural device for “shifting the burden
of production,” or for “shifting both the burden of produc
tion and the burden of persuasion.” Brief for Petitioner
21–22 (emphasis deleted). Whatever the significance of a
10         MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                          Opinion of the Court

presumption in the abstract, basic principles of statutory
construction require us to assume that Congress meant to
incorporate “the cluster of ideas” attached to the common
law term it adopted. Beck, 529 U. S., at 501 (internal
quotation marks omitted). And RCA leaves no doubt that
attached to the common-law presumption of patent valid
ity was an expression as to its “force,” 293 U. S., at 7—that
is, the standard of proof required to overcome it.6
   Resisting the conclusion that Congress adopted the
heightened standard of proof reflected in our pre-1952
cases, Microsoft contends that those cases applied a clear
and-convincing standard of proof only in two limited
circumstances, not in every case involving an invalidity
defense. First, according to Microsoft, the heightened
standard of proof applied in cases “involving oral testi
mony of prior invention,” simply to account for the unreli
ability of such testimony. Brief for Petitioner 25. Second,
Microsoft tells us, the heightened standard of proof ap
plied to “invalidity challenges based on priority of inven
tion,” where that issue had previously been litigated
between the parties in PTO proceedings. Id., at 28.
   Squint as we may, we fail to see the qualifications that
Microsoft purports to identify in our cases. They certainly
make no appearance in RCA’s explanation of the presump
——————
  6 Microsoft objects that this reading of §282 “conflicts with the usual

understanding of presumptions.” Reply Brief for Petitioner 4. In sup
port, it relies on the “understanding” reflected in Federal Rule of
Evidence 301, which explains the ordinary effect of a presumption in
federal civil actions. That Rule, however, postdates the 1952 Act by
nearly 30 years, and it is not dispositive of how Congress in 1952
understood presumptions generally, much less the presumption of pat
ent validity. In any event, the word “presumption” has often been
used when another term might be more accurate. See Thayer 335
(“Often . . . maxims and ground principles get expressed in this form of
a presumption perversely and inaccurately”). And, to the extent
Congress used the words “presumed valid” in an imprecise way, we
cannot fault it for following our lead.
                 Cite as: 564 U. S. ____ (2011)           11

                     Opinion of the Court

tion of patent validity. RCA simply said, without qualifi
cation, “that one otherwise an infringer who assails the
validity of a patent fair upon its face bears a heavy burden
of persuasion, and fails unless his evidence has more than
a dubious preponderance.” 293 U. S., at 8; see also id., at
7 (“A patent regularly issued, and even more obviously
a patent issued after a hearing of all the rival claimants,
is presumed to be valid until the presumption has been
overcome by convincing evidence of error” (emphasis
added)). Nor do they appear in any of our cases as express
limitations on the application of the heightened standard
of proof. Cf., e.g., Smith v. Hall, 301 U. S. 216, 233 (1937)
(citing RCA for the proposition that a “heavy burden of
persuasion . . . rests upon one who seeks to negative nov
elty in a patent by showing prior use”); Mumm v. Jacob E.
Decker & Sons, 301 U. S. 168, 171 (1937) (“Not only is the
burden to make good this defense upon the party setting it
up, but his burden is a heavy one, as it has been held that
every reasonable doubt should be resolved against him”
(internal quotation marks omitted)). In fact, Microsoft
itself admits that our cases “could be read as announcing a
heightened standard applicable to all invalidity asser
tions.” Brief for Petitioner 30 (emphasis deleted).
   Furthermore, we cannot agree that Microsoft’s proposed
limitations are inherent—even if unexpressed—in our
pre-1952 cases. As early as 1874 we explained that the
burden of proving prior inventorship “rests upon [the de
fendant], and every reasonable doubt should be resolved
against him,” without tying that rule to the vagaries and
manipulability of oral testimony. Coffin v. Ogden, 18
Wall. 120, 124 (1874). And, more than 60 years later, we
applied that rule where the evidence in support of a prior
use defense included documentary proof—not just oral
testimony—in a case presenting no priority issues at all.
See Smith, 301 U. S., at 221, 233. Thus, even if Congress
searched for some unstated limitations on the heightened
12         MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                          Opinion of the Court

standard of proof in our cases, it would have found none.7
  Microsoft also argues that the Federal Circuit’s inter
pretation of §282’s statement that “[a] patent shall be pre
sumed valid” must fail because it renders superfluous
the statute’s additional statement that “[t]he burden of
establishing invalidity of a patent . . . shall rest on the
party asserting such invalidity.” We agree that if the
presumption imposes a heightened standard of proof on
the patent challenger, then it alone suffices to establish
that the defendant bears the burden of persuasion. Cf.
Director, Office of Workers’ Compensation Programs v.
Greenwich Collieries, 512 U. S. 267, 278 (1994) (“A stan
dard of proof . . . can apply only to a burden of persua
sion”). Indeed, the Federal Circuit essentially recognized
as much in American Hoist. See 725 F. 3d, at 1359.
  But the canon against superfluity assists only where a
competing interpretation gives effect “ ‘to every clause and
word of a statute.’ ” Duncan v. Walker, 533 U. S. 167, 174

——————
  7 In a similar vein, Microsoft insists that there simply was no settled

presumption of validity for Congress to codify in 1952. Microsoft points
to a handful of district court decisions, which “question[ed] whether any
presumption of validity was warranted,” or which “required the pat
entee to prove the validity of his patent by a preponderance of the
evidence.” Brief for Petitioner 24 (emphasis deleted; brackets and
internal quotation marks omitted); see, e.g., Ginsberg v. Railway
Express Agency, Inc., 72 F. Supp. 43, 44 (SDNY 1947) (stating, in dicta,
that “[i]t may now well be said that no presumption whatever arises
from the grant of patent”); see also post, at 1 (THOMAS, J., concurring in
judgment). RCA makes clear, however, that the presumption of patent
validity had an established meaning traceable to the mid-19th century,
293 U. S. 1, 7–8 (1934); that some lower courts doubted its wisdom or
even pretended it did not exist is of no moment. Microsoft may be
correct that Congress enacted §282 to correct lower courts that required
the patentee to prove the validity of a patent. See American Hoist &
Derrick Co. v. Sowa & Sons, Inc., 725 F. 2d 1350, 1359 (CA Fed. 1984).
But the language Congress selected reveals its intent not only to specify
that the defendant bears the burden of proving invalidity but also that
the evidence in support of the defense must be clear and convincing.
                      Cite as: 564 U. S. ____ (2011)                      13

                           Opinion of the Court

(2001) (quoting United States v. Menasche, 348 U. S. 528,
538–539 (1955)); see Bruesewitz v. Wyeth LLC, 562 U. S.
___, ___ (2011) (slip op., at 12). Here, no interpretation of
§282—including the two alternatives advanced by Micro
soft—avoids excess language. That is, if the presumption
only “allocates the burden of production,” Brief for Peti
tioner 21, or if it instead “shift[s] both the burden of pro
duction and the burden of persuasion,” id., at 22 (empha
sis deleted), then it would be unnecessary in light of §282’s
statement that the challenger bears the “burden of estab
lishing invalidity.” See 21B Fed. Practice §5122, at 401
(“[T]he same party who has the burden of persuasion also
starts out with the burden of producing evidence”). “There
are times when Congress enacts provisions that are super
fluous,” Corley v. United States, 556 U. S. ___, ___ (2009)
(ALITO, J., dissenting) (slip op., at 3), and the kind of
excess language that Microsoft identifies in §282 is hardly
unusual in comparison to other statutes that set forth a
presumption, a burden of persuasion, and a standard of
proof. Cf., e.g., 28 U. S. C. §2254(e)(1).8
——————
  8 For  those of us for whom it is relevant, the legislative history of §282
provides additional evidence that Congress meant to codify the judge
made presumption of validity, not to set forth a new presumption of
its own making. The accompanying House and Senate Reports both
explain that §282 “introduces a declaration of the presumption of va
lidity of a patent, which is now a statement made by courts in deci
sions, but has had no expression in the statute.” H. R. Rep. No. 1923,
82d Cong., 2d Sess., 10 (1952) (hereinafter H. R. Rep.); S. Rep. No.
1979, 82d Cong., 2d Sess., 9 (1952) (hereinafter S. Rep.). To the same
effect, the Reviser’s Note indicates that §282’s “first paragraph declares
the existing presumption of validity of patents.” Note following 35
U. S. C. §282 (1952 ed.).
   Prior to 1952, the existing patent laws already incorporated the sum
and substance of the presumption as Microsoft would define it—that is,
they “assign[ed] the burden of proving invalidity to the accused in
fringer,” Brief for Petitioner 14 (emphasis deleted). See 35 U. S. C. §69
(1946 ed.) (providing that a defendant in an infringement action “may
plead” and “prove on trial” the invalidity of the patent as a defense); see
14          MICROSOFT CORP. v. i4i LTD. PARTNERSHIP 


                           Opinion of the Court 


                                B

  Reprising the more limited argument that it pressed
below, Microsoft argues in the alternative that a prepon
derance standard must at least apply where the evidence
before the factfinder was not before the PTO during the
examination process. In particular, it relies on KSR
Int’l Co. v. Teleflex Inc., 550 U. S. 398 (2007), where we ob
served that, in these circumstances, “the rationale under
lying the presumption—that the PTO, in its expertise, has
approved the claim—seems much diminished.” Id., at 426.
  That statement is true enough, although other ration
ales may animate the presumption in such circumstances.
See The Barbed Wire Patent, 143 U. S. 275, 292 (1892)
(explaining that because the patentee “first published this
device; put it upon record; made use of it for a practical
purpose; and gave it to the public . . . . doubts . . . concern
ing the actual inventor . . . should be resolved in favor
of the patentee”); cf. Brief for United States as Amicus
Curiae 33 (arguing that even when the administrative cor
rectness rationale has no relevance, the heightened stan
dard of proof “serves to protect the patent holder’s reliance
interests” in disclosing an invention to the public in
exchange for patent protection). The question remains,
however, whether Congress has specified the applicable
——————
also Patent Act of 1870, ch. 230, §61, 16 Stat. 208 (same); Patent Act of
1836, ch. 357, §15, 5 Stat. 123 (similar); Patent Act of 1793, ch. II, §6, 1
Stat. 322 (similar); Coffin, 18 Wall., at 124 (explaining that the Patent
Act of 1836 “allowed a party sued for infringement to prove, among
other defences, that the patentee was not the original and first inventor
of the thing patented, or of a substantial and material part thereof
claimed to be new” (internal quotation marks omitted)). The House and
Senate Reports state, however, that §282 established a principle that
previously “had no expression in the statute.” H. R. Rep., at 10; S. Rep.,
at 9. Thus, because the only thing missing from §282’s predecessor was
the heightened standard of proof itself, Congress must have understood
the presumption of patent validity to include the heightened standard
of proof attached to it.
                     Cite as: 564 U. S. ____ (2011)                   15

                          Opinion of the Court

standard of proof. As established, Congress did just that
by codifying the common-law presumption of patent valid
ity and, implicitly, the heightened standard of proof at
tached to it.
   Our pre-1952 cases never adopted or endorsed the kind
of fluctuating standard of proof that Microsoft envisions.
And they do not indicate, even in dicta, that anything less
than a clear-and-convincing standard would ever apply to
an invalidity defense raised in an infringement action. To
the contrary, the Court spoke on this issue directly in
RCA, stating that because the heightened standard of
proof applied where the evidence before the court was
“different” from that considered by the PTO, it applied
even more clearly where the evidence was identical. 293
U. S., at 8. Likewise, the Court’s statement that a “dubi
ous preponderance” will never suffice to sustain an inva
lidity defense, ibid., admitted of no apparent exceptions.
Finally, this Court often applied the heightened standard
of proof without any mention of whether the relevant
prior-art evidence had been before the PTO examiner, in
circumstances strongly suggesting it had not. See, e.g.,
Smith, 301 U. S., at 227, 233.9
   Nothing in §282’s text suggests that Congress meant to
——————
  9 Microsoft cites numerous court of appeals decisions as support for
its claim that a preponderance standard must apply in the event that
the evidence in the infringement action varies from that considered by
the PTO. We see no hint of the hybrid standard of proof that Microsoft
advocates in these cases. Indeed, in some of these cases it appears that
the court even evaluated the evidence according to a heightened stan
dard of proof. See Jacuzzi Bros., Inc. v. Berkeley Pump Co., 191 F. 2d
632, 634 (CA9 1951) (“Although it is not expressly stated that th[e]
conclusion [of invalidity] is based upon evidence establishing the thesis
beyond a reasonable doubt, the Trial Court expressed no doubt. And
the record shows that such conclusion was supported by substantial
evidence”); Western Auto Supply Co. v. American-National Co., 114
F. 2d 711, 713 (CA6 1940) (concluding that the patent was invalid
where the court “entertain[ed] no doubt” on the question).
16          MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                           Opinion of the Court

depart from that understanding to enact a standard of
proof that would rise and fall with the facts of each
case. Indeed, had Congress intended to drop the heightened
standard of proof where the evidence before the jury var
ied from that before the PTO—and thus to take the un
usual and impractical step of enacting a variable standard
of proof that must itself be adjudicated in each case, cf.
Santosky v. Kramer, 455 U. S. 745, 757 (1982)10—we as
sume it would have said so expressly.
  To be sure, numerous courts of appeals in the years
preceding the 1952 Act observed that the presumption of
validity is “weakened” or “dissipated” in the circumstance
that the evidence in an infringement action was never
considered by the PTO. See Jacuzzi Bros., Inc. v. Berkeley
Pump Co., 191 F. 2d 632, 634 (CA9 1951) (“largely dissi
pated”); H. Schindler & Co. v. C. Saladino & Sons, 81
F. 2d 649, 651 (CA1 1936) (“weakened”); Gillette Safety
Razor Co. v. Cliff Weil Cigar Co., 107 F. 2d 105, 107 (CA4
1939) (“greatly weakened”); Butler Mfg. Co. v. Enterprise
Cleaning Co., 81 F. 2d 711, 716 (CA8 1936) (“weakened”).
But we cannot read these cases to hold or even to suggest
that a preponderance standard would apply in such cir
——————
   10 Not the least of the impracticalities of such an approach arises from

the fact that whether a PTO examiner considered a particular reference
will often be a question without a clear answer. In granting a patent,
an examiner is under no duty to cite every reference he considers. 1
Dept. of Commerce, PTO, Manual of Patent Examining Procedure
§904.03, p. 900–51 (8th rev. ed. 2010) (“The examiner is not called upon
to cite all references that may be available, but only the ‘best.’ Multiply
ing references, any one of which is as good as, but no better than, the
others, adds to the burden and cost of prosecution and should therefore
be avoided” (emphasis deleted)); Manual of Patent Examining Proce
dure §904.02, p. 129 (1st rev. ed. 1952) (same), http://www.uspto.gov/
web/offices/pac/mpep/old/E1R3_900.pdf (all Internet materials as
visited June 6, 2011, and available in Clerk of Court’s case file); see also
Brief for Respondents 45–46 (describing additional impracticalities).
We see no indication in §282 that Congress meant to require collateral
litigation on such an inherently uncertain question.
                 Cite as: 564 U. S. ____ (2011)         17

                     Opinion of the Court

cumstances, and we decline to impute such a reading to
Congress. Instead, we understand these cases to reflect
the same commonsense principle that the Federal Circuit
has recognized throughout its existence—namely, that
new evidence supporting an invalidity defense may “carry
more weight” in an infringement action than evidence
previously considered by the PTO, American Hoist, 725
F. 2d, at 1360. 	As Judge Rich explained:
    “When new evidence touching validity of the patent
    not considered by the PTO is relied on, the tribunal
    considering it is not faced with having to disagree
    with the PTO or with deferring to its judgment or
    with taking its expertise into account. The evidence
    may, therefore, carry more weight and go further to
    ward sustaining the attacker’s unchanging burden.”
    Ibid. (emphasis deleted)
See also SIBIA Neurosciences, Inc. v. Cadus Pharmaceuti
cal Corp., 225 F. 3d 1349, 1355–1356 (CA Fed. 2000)
(“[T]he alleged infringer’s burden may be more easily car
ried because of th[e] additional [evidence]”); Group One,
Ltd. v. Hallmark Cards, Inc., 407 F. 3d 1297, 1306 (CA
Fed. 2005) (similar).
   Simply put, if the PTO did not have all material facts
before it, its considered judgment may lose significant
force. Cf. KSR, 550 U. S., at 427. And, concomitantly, the
challenger’s burden to persuade the jury of its invalidity
defense by clear and convincing evidence may be easier to
sustain. In this respect, although we have no occasion to
endorse any particular formulation, we note that a jury
instruction on the effect of new evidence can, and when
requested, most often should be given. When warranted,
the jury may be instructed to consider that it has heard
evidence that the PTO had no opportunity to evaluate
before granting the patent. When it is disputed whether
the evidence presented to the jury differs from that evalu
18       MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                      Opinion of the Court

ated by the PTO, the jury may be instructed to consider
that question. In either case, the jury may be instructed
to evaluate whether the evidence before it is materially
new, and if so, to consider that fact when determining
whether an invalidity defense has been proved by clear
and convincing evidence. Cf., e.g., Mendenhall v. Cedarap
ids, Inc., 5 F. 3d 1557, 1563–1564 (CA Fed. 1993); see
also Brief for International Business Machines Corp. as
Amicus Curiae 31–37. Although Microsoft emphasized in
its argument to the jury that S4 was never considered by
the PTO, it failed to request an instruction along these
lines from the District Court. Now, in its reply brief in
this Court, Microsoft insists that an instruction of this
kind was warranted. Reply Brief for Petitioner 22–23.
That argument, however, comes far too late, and we there
fore refuse to consider it. See Rent-A-Center, West, Inc. v.
Jackson, 561 U. S. ___ , ___ (2010) (slip op., at 12); cf. Fed.
Rule Civ. Proc. 51(d)(1)(B).
                              III
   The parties and their amici have presented opposing
views as to the wisdom of the clear-and-convincing
evidence standard that Congress adopted. Microsoft and
its amici contend that the heightened standard of proof
dampens innovation by unduly insulating “bad” patents
from invalidity challenges. They point to the high invali
dation rate as evidence that the PTO grants patent protec
tion to too many undeserving “inventions.” They claim
that inter partes reexamination proceedings before the
PTO cannot fix the problem, as some grounds for invalida
tion (like the on-sale bar at issue here) cannot be raised in
such proceedings. They question the deference that the
PTO’s expert determinations warrant, in light of the
agency’s resources and procedures, which they deem in
adequate. And, they insist that the heightened standard
of proof essentially causes juries to abdicate their role in
                 Cite as: 564 U. S. ____ (2011)           19

                     Opinion of the Court

reviewing invalidity claims raised in infringement actions.
   For their part, i4i and its amici, including the United
States, contend that the heightened standard of proof
properly limits the circumstances in which a lay jury
overturns the considered judgment of an expert agency.
They claim that the heightened standard of proof is an
essential component of the patent “bargain,” see Bonito
Boats, Inc. v. Thunder Craft Boats, Inc., 489 U. S. 141,
150–151 (1989), and the incentives for inventors to dis
close their innovations to the public in exchange for patent
protection. They disagree with the notion that the patent
issuance rate is above the optimal level. They explain that
limits on the reexamination process reflect a judgment by
Congress as to the appropriate degree of interference with
patentees’ reliance interests. Finally, they maintain that
juries that are properly instructed as to the application of
the clear-and-convincing-evidence standard can, and often
do, find an invalidity defense established.
   We find ourselves in no position to judge the compara
tive force of these policy arguments. For nearly 30 years,
the Federal Circuit has interpreted §282 as we do today.
During this period, Congress has often amended §282, see,
e.g., Pub. L. 104–141, §2, 109 Stat. 352; Pub. L. 98–417,
§203, 98 Stat. 1603; not once, so far as we (and Microsoft)
are aware, has it even considered a proposal to lower the
standard of proof, see Tr. Oral Arg. 10. Moreover, Con
gress has amended the patent laws to account for concerns
about “bad” patents, including by expanding the reexami
nation process to provide for inter partes proceedings. See
Optional Inter Partes Reexamination Procedure Act of
1999, 113 Stat. 1501A–567, codified at 35 U. S. C. §311 et
seq. Through it all, the evidentiary standard adopted in
§282 has gone untouched. Indeed, Congress has left the
Federal Circuit’s interpretation of §282 in place despite
ongoing criticism, both from within the Federal Govern
20          MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                          Opinion of the Court

ment and without.11
  Congress specified the applicable standard of proof
in 1952 when it codified the common-law presumption of
patent validity. Since then, it has allowed the Federal
Circuit’s correct interpretation of §282 to stand. Any re
calibration of the standard of proof remains in its hands.
                       *    *      *
 For the reasons stated, the judgment of the Court of
Appeals for the Federal Circuit is
                                            Affirmed.

  THE CHIEF JUSTICE took no part in the consideration or
decision of this case.




——————
  11 See, e.g., FTC, To Promote Innovation: The Proper Balance of Com
petition and Patent Law and Policy 28 (Oct. 2003), http://www.ftc.gov/
os/2003/10/innovationrpt.pdf (recommending that “legislation be
enacted specifying that challenges to the validity of a patent be deter
mined based on a preponderance of the evidence”); Alsup, Memo to
Congress: A District Judge’s Proposal for Patent Reform, 24 Berkeley
Tech. L. J. 1647, 1655 (2009) (same); Lichtman & Lemley, Rethinking
Patent Law’s Presumption of Validity, 60 Stan. L. Rev. 45, 60 (2007)
(proposing “statutory amendment or . . . judicial reinterpretation of the
existing statute and its associated case law” to lower the standard of
proof to a preponderance of the evidence (footnote omitted)).
                 Cite as: 564 U. S. ____ (2011)           1

                    BREYER, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                          No. 10–290
                         _________________


   MICROSOFT CORPORATION, PETITIONER v. i4i 

         LIMITED PARTNERSHIP ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

           APPEALS FOR THE FEDERAL CIRCUIT

                        [June 9, 2011]


   JUSTICE BREYER, with whom JUSTICE SCALIA and JUS-
TICE ALITO join, concurring.
   I join the Court’s opinion in full. I write separately be
cause, given the technical but important nature of the
invalidity question, I believe it worth emphasizing that in
this area of law as in others the evidentiary standard of
proof applies to questions of fact and not to questions of
law. See, e.g., Addington v. Texas, 441 U. S. 418, 423
(1979). Thus a factfinder must use the “clear and convinc
ing” standard where there are disputes about, say, when a
product was first sold or whether a prior art reference had
been published.
   Many claims of invalidity rest, however, not upon fac
tual disputes, but upon how the law applies to facts as
given. Do the given facts show that the product was pre
viously “in public use”? 35 U. S. C. §102(b). Do they show
that the invention was “nove[l]” and that it was “non
obvious”? §§102, 103. Do they show that the patent ap
plicant described his claims properly? §112. Where the
ultimate question of patent validity turns on the correct
answer to legal questions—what these subsidiary legal
standards mean or how they apply to the facts as given—
today’s strict standard of proof has no application. See,
e.g., Graham v. John Deere Co. of Kansas City, 383 U. S. 1,
17 (1966); Minnesota Mining & Mfg. Co. v. Chemque, Inc.,
2        MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

                    BREYER, J., concurring

303 F. 3d 1294, 1301 (CA Fed. 2002); Transocean Offshore
Deepwater Drilling, Inc. v. Maersk Contractors USA, Inc.,
617 F. 3d 1296, 1305 (CA Fed. 2010); cf. Markman v.
Westview Instruments, Inc., 517 U. S. 370 (1996).
   Courts can help to keep the application of today’s “clear
and convincing” standard within its proper legal bounds
by separating factual and legal aspects of an invalidity
claim, say, by using instructions based on case-specific
circumstances that help the jury make the distinction or
by using interrogatories and special verdicts to make clear
which specific factual findings underlie the jury’s conclu
sions. See Fed. Rules Civ. Proc. 49 and 51. By isolating
the facts (determined with help of the “clear and convinc
ing” standard), courts can thereby assure the proper in
terpretation or application of the correct legal standard
(without use of the “clear and convincing” standard). By
preventing the “clear and convincing” standard from roam
ing outside its fact-related reservation, courts can increase
the likelihood that discoveries or inventions will not re
ceive legal protection where none is due.
                 Cite as: 564 U. S. ____ (2011)            1

               THOMAS, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 10–290
                          _________________


   MICROSOFT CORPORATION, PETITIONER v. i4i 

         LIMITED PARTNERSHIP ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

           APPEALS FOR THE FEDERAL CIRCUIT

                         [June 9, 2011]


    JUSTICE THOMAS, concurring in the judgment.
    I am not persuaded that Congress codified a standard of
proof when it stated in the Patent Act of 1952 that “[a]
patent shall be presumed valid.” 35 U. S. C. §282; see
ante, at 7. “[W]here Congress borrows terms of art,” this
Court presumes that Congress “knows and adopts the
cluster of ideas that were attached to each borrowed word
. . . and the meaning its use will convey to the judicial
mind.” Morissette v. United States, 342 U. S. 246, 263
(1952). But I do not think that the words “[a] patent shall
be presumed valid” so clearly conveyed a particular stan
dard of proof to the judicial mind in 1952 as to constitute
a term of art. See, e.g., ante, at 12, n. 7 (“[S]ome lower
courts doubted [the presumption’s] wisdom or even pre
tended it did not exist”); Philip A. Hunt Co. v. Mallinck
rodt Chemical Works, 72 F. Supp. 865, 869 (EDNY 1947)
(“[T]he impact upon the presumption of many late deci
sions seems to have rendered it as attenuated . . . as the
shadow of a wraith”); Myers v. Beall Pipe & Tank Corp., 90
F. Supp. 265, 268 (D Ore. 1948) (“[T]he presumption of
[patent] validity . . . is treated by the appellate courts as
evanescent as a cloud”); American Hoist & Derrick Co. v.
Sowa & Sons, Inc., 725 F. 2d 1350, 1359 (CA Fed. 1984)
(“[I]n 1952, the case law was far from consistent—even
contradictory—about the presumption”); cf. Bruesewitz v.
2        MICROSOFT CORP. v. i4i LTD. PARTNERSHIP

               THOMAS, J., concurring in judgment

Wyeth LLC, 562 U. S. ___, ___–___ (2011) (slip op., at 9–
10) (Congress’ use of a word that is similar to a term of art
does not codify the term of art). Therefore, I would not
conclude that Congress’ use of that phrase codified a stan
dard of proof.
  Nevertheless, I reach the same outcome as the Court.
Because §282 is silent as to the standard of proof, it did
not alter the common-law rule. See ante, at 6 (“[§282]
includes no express articulation of the standard of proof”).
For that reason, I agree with the Court that the height
ened standard of proof set forth in Radio Corp. of Amer-
ica v. Radio Engineering Laboratories, Inc., 293 U. S. 1
(1934)—which has never been overruled by this Court or
modified by Congress—applies.
