dissenting.
Six years ago in Gregg v. Georgia, 428 U. S. 153, 193 (1976) (joint opinion of Stewart, Powell, and Stevens, JJ.), this Court declared:
“Juries are invariably given careful instructions on the law and how to apply it before they are authorized to decide the merits of a lawsuit. It would be virtually unthinkable to follow any other course in a legal system that has traditionally operated by following prior precedents and fixed rules of law. . . . When erroneous instructions are given, retrial is often required. It is quite simply a hallmark of our legal system that juries be carefully and adequately guided in their deliberations.” (Footnote omitted.)
In today’s decision, a majority of this Court intimates that a post hoc construction of a death penalty statute by the State’s highest court may remedy the fact that a jury was improperly instructed with respect to the very factors that save the Georgia statute from unconstitutionality. See Gregg v. Georgia, supra. Because I cannot see how the Georgia Supreme Court’s response to this Court’s certification could constitutionally justify the imposition of the death penalty in this case, I must dissent.
I
I adhere to my view that the death penalty is in all circumstances cruel and unusual punishment prohibited by the *418Eighth and Fourteenth Amendments. Gregg v. Georgia, supra, at 231. Even if I believed that the death penalty could constitutionally be imposed under certain circumstances, however, I believe that respondent Stephens’ sentence must be vacated and his case remanded to the Georgia state courts for resentencing.
II
In my opinion, remanding this case for resentencing is compelled by this Court’s decisions upholding the constitutionality of the Georgia death penalty statute, and by well-recognized principles of appellate review. Therefore, whether or not the Georgia Supreme Court’s construction of the statute in response to this Court’s certification might avoid the constitutional infirmity inherent in respondent’s sentence in some future case, it can do nothing to alter the fact that respondent’s death sentence may have been based in part on consideration of an unconstitutional aggravating circumstance.
Under Georgia law, certification is appropriate “[w]hen it shall appear to the Supreme Court of the United States . . . that there are involved in any proceeding before it questions or propositions of the laws of this State which are determinative of said cause and there are no clear controlling precedents in the appellate court decisions of this State.” Ga. Code § 24-4536(a) (Supp. 1980) (emphasis added). The majority attempts to bring this case within the ambit of this certification procedure by indicating that “[i]t may be that . . . multiple findings of statutory aggravating circumstances are superfluous, or . . . the reviewing court may assume the role of the jury when the sentencing jury recommended the death penalty under legally erroneous instructions.” Ante, at 415. The majority then requests the Georgia Supreme Court to clarify “the premises of state law that support the conclusion that the death sentence in this case is not impaired *419by the invalidity of one of the statutory aggravating circumstances found by the jury.” Ante, at 416-417.
I wholeheartedly agree that we do not know the answers to these questions. The majority recognizes that we do not possess this information because “[t]he Georgia Supreme Court has never explained the rationale for its position” that a death sentence may be reaffirmed when one of the aggravating circumstances relied on by the jury is declared invalid. Ante, at 415. I submit, however, that we are not alone in our ignorance. There is absolutely no indication that the jury sentencing respondent to death or the judge who instructed that jury was any more aware of the answers to these questions than we are today. Indeed, by certifying these questions to the Georgia Supreme Court, the majority concedes that it was impossible for anyone to know the answers to these questions at the time respondent was sentenced to death, because “there are no controlling precedents” in Georgia on these issues. Given this Court’s prior treatment of cases in which a defendant received a sentence, particularly a death sentence, on the basis of erroneous jury instructions, I do not understand how the Georgia Supreme Court’s answer to the certified question could possibly be “determinative” of this case.
In Furman v. Georgia, 408 U. S. 238 (1972), this Court struck down death penalties imposed pursuant to a Georgia statute. Shortly thereafter, the Georgia Legislature enacted the current death penalty statute. This statute provides for a separate sentencing proceeding after the defendant has been found guilty of a capital offense. During the sentencing phase, the trial judge shall instruct the jury1 to consider “any of the [10] statutory aggravating circumstances which may be supported by the evidence.” Ga. Code § 27-2534.1(b) (1978). The aggravating circumstances found *420by the judge to be warranted by the evidence are submitted to the jury in writing to be used during its deliberations. § 27-2534.1(c). If the jury recommends a death sentence, it “shall designate in writing ... the aggravating circumstance or circumstances which it found beyond a reasonable doubt.” Ibid. Even if it finds that one or more aggravating circumstances has been established beyond a reasonable doubt, the jury is not required to impose the death penalty. See Bowen v. State, 241 Ga. 492, 246 S. E. 2d 322 (1978). The jury’s verdict to impose the death penalty must be unanimous. Miller v. State, 237 Ga. 557, 229 S. E. 2d 376 (1976). The trial judge is bound by the jury’s recommendation of sentence, whether that recommendation be life or death. Ga. Code §§ 26-3102, 27-2514 (1978).
In Gregg v. Georgia, 428 U. S. 153 (1976), this Court held that this statutory scheme satisfied the constitutional guarantee against cruel and unusual punishment. In reaching this conclusion, the two principal opinions relied heavily on the fact that the aggravating circumstances served to guide the jury’s discretion. The joint opinion announcing the judgment of the Court emphasized that because “the members of a jury will have had little, if any, previous experience in sentencing,” id., at 192 (opinion of Stewart, Powell, and Stevens, JJ.), they should be given specific standards to guide their sentencing deliberations, such as those provided in the Model Penal Code, which catalogs “ ‘the main circumstances of aggravation and of mitigation that should be weighed and weighed against each other’” by the jury. Id., at 193 (quoting ALI, Model Penal Code § 201.6, Comment 3, p. 71 (Tent. Draft No. 9, 1959)) (emphasis in original). That opinion found that the new Georgia statute satisfied this requirement because, through the statutory aggravating circumstances, “[t]he new Georgia sentencing procedures . . . focus the jury’s attention on the particularized nature of the crime and the particularized characteristics of the individual defendant.” 428 U. S., at 206 (emphasis added). Justice White, *421joined by The Chief Justice and Justice Rehnquist, concurring in the judgment, placed an even stronger emphasis on the role of the statutory aggravating circumstances:
“The Georgia Legislature has plainly made an effort to guide the jury in the exercise of its discretion, while at the same time permitting the jury to dispense mercy on the basis of factors too intangible to write into a statute .... As the types of murders for which the death penalty may be imposed become more narrowly defined and are limited to those which are particularly serious or for which the death penalty is peculiarly appropriate as they are in Georgia by reason of the aggravating-circumstance requirement, it becomes reasonable to expect that juries — even given discretion not to impose the death penalty — will impose the death penalty in a substantial portion of the cases so defined.” Id., at 222 (first emphasis added).
In Godfrey v. Georgia, 446 U. S. 420, 428 (1980) (plurality opinion of Stewart, J., joined by Blackmun, Powell, and Stevens, JJ.), this Court reaffirmed the role of aggravating circumstances in protecting against the arbitrary imposition of the death penalty. The Godfrey Court addressed the constitutionality of a death sentence imposed in reliance on aggravating circumstance § (b)(7), which allows a jury to impose the death sentence if it finds that the murder “was outrageously or wantonly vile, horrible or inhuman in that it involved torture, depravity of mind, or an aggravated battery to the victim.” Ga. Code § 27-2534.1(b)(7) (1978).
The plurality opinion found: “There is nothing in these few words, standing alone, that implies any inherent restraint on the arbitrary and capricious infliction of the death sentence. A person of ordinary sensibility could fairly characterize almost every murder as ‘outrageously or wantonly vile, horrible and inhuman.’ ” 446 U. S., at 428-429. Section (b)(7), if construed broadly enough to encompass every murder, would *422be unconstitutional because it provides “no principled way to distinguish this case, in which the death penalty was imposed, from the many cases in which it was not.” Id., at 433. The plurality found it significant that this interpretation of § (b)(7) “may . . . have been one to which the members of the jury in this case subscribed,” and that, if the jury did hold this view “their preconceptions were not dispelled by the trial judge’s sentencing instructions.” Id., at 429. Therefore, the jury was not given appropriate guidance, and the death sentence could not constitutionally be imposed.
In my view, this reasoning requires that respondent’s death sentence be vacated and that this case be remanded so he can be resentenced by a properly instructed jury. It is conceded that the jury in this case was instructed on an aggravating circumstance that the Georgia Supreme Court has since declared unconstitutional. If this were the only aggravating circumstance found by the jury, it is also undisputed that the State would be unable to impose the death sentence, see Arnold v. State, 236 Ga. 534, 224 S. E. 2d 386 (1976), even if the Georgia Supreme Court determined that the evidence supported a finding of other statutory aggravating circumstances. Cf. Presnell v. Georgia, 439 U. S. 14, 16 (1978). Petitioner argues, however, because the jury found two other statutory aggravating circumstances that the Georgia Supreme Court found to be supported by the evidence, that court could reaffirm the death sentence. This argument flies in the face of the reasoning of the Godfrey plurality which found it crucial that the jury’s decision to impose the death sentence be guided by clear and appropriate instructions.
Moreover, this argument is patently contrary to the settled principle that “if the jury has been instructed to consider several grounds for conviction, one of which proves to be unconstitutional, and the reviewing court is thereafter unable to determine from the record whether the jury relied on the unconstitutional ground, the verdict must be set aside.” 631 F. 2d 397, 406 (CA5 1980) (case below); see Stromberg v. *423California, 283 U. S. 359 (1931). Since 1931, this Court has consistently declined to speculate about whether a particular jury would have reached the same conclusion in the absence of an unconstitutional instruction. See, e. g., id., at 367-368. Accord, Bachellar v. Maryland, 397 U. S. 564, 570-571 (1970); Street v. New York, 394 U. S. 576, 585-588 (1969); Yates v. United States, 354 U. S. 298, 311-312 (1957). In light of this Court’s consistent recognition that “the penalty of death is qualitatively different from a sentence of imprisonment,” Woodson v. North Carolina, 428 U. S. 280, 305 (1980) (opinion of Stewart, Powell, and Stevens, JJ.); see, e. g., Eddings v. Oklahoma, 455 U. S. 104, 117-118 (1982) (O’Connor, J., concurring), there is certainly no reason to engage in such speculation here. Yet, the jury is not required to recommend death even if it finds that one or more aggravating circumstances have been established beyond a reasonable doubt. Therefore, to adopt the bald pronouncement that “[wjhere two or more statutory aggravating circumstances are found by the jury, the failure of one circumstance does not so taint the proceedings as to invalidate the other aggravating circumstance found and the sentence of death thereon,” Gates v. State, 244 Ga. 587, 599, 261 S. E. 2d 349, 358 (1979), we would have to speculate that the jury’s decision to impose the death penalty was not influenced by the presence of the unconstitutional aggravating circumstance.2
Recognizing that settled law normally requires that sentences arguably imposed on the basis of unconstitutional instructions cannot stand, petitioner and several States in an *424amicus curiae brief3 attempt to distinguish the Stromberg line of cases by arguing that, as a matter of statutory construction, a jury’s finding that 1 of the 10 aggravating circumstances has been established beyond a reasonable doubt is irrelevant to its ultimate conclusion that the death penalty should be imposed. Specifically, petitioner argues that the term “aggravating circumstance” actually has two entirely different meanings, with each meaning representing a separate task that a capital sentencing jury must perform. First, the jury must determine whether any of the 10 statutory “aggravating circumstances” has been established beyond a reasonable doubt. This, petitioner argues, is a threshold determination that only allows the jury to consider the death penalty, but has no impact on whether that penalty should be imposed. After reaching this threshold determination, the jury may consider any “evidence in aggravation” or mitigation in reaching its conclusion as to whether the dealth penalty should be imposed. According to petitioner, the jury performs this second task free of any influence from the very “legislative guidelines” that, by “focus[ing] the jury’s attention on the particularized nature of the crime and the particularized characteristics of the individual defendant,” prevent the death penalty from being wantonly and freakishly imposed. Gregg v. Georgia, 428 U. S., at 206-207 (joint opinion of Stewart, POWELL, and Stevens, JJ.).
Putting to one side both the plausibility and the constitutionality of petitioner’s construction of the Georgia death penalty statute,4 it is patently obvious that this ex post facto at*425tempt to avoid the clear mandate of Stromberg cannot possibly remedy the constitutional infirmity of respondent’s sentence. This conclusion is compelled by this Court’s decision in Sandstrom v. Montana, 442 U. S. 510 (1979). In Sandstrom, a defendant was convicted of “deliberate homicide,” which, under Montana law, required the State to prove that he “purposefully or knowingly” caused the death of the victim. Id., at 512. At the close of all the evidence, the judge instructed the jury that “‘[t]he law presumes that a person intends the ordinary consequences of his voluntary acts.’” Id., at 513. The defendant objected to this instruction on the ground that it unconstitutionally shifted the burden of proof on the issue of intent. On direct appeal, the Montana Supreme Court conceded that shifting the burden of proof in a criminal case was unconstitutional. It nevertheless upheld the challenged instruction on the ground that under its interpretation, the instruction only shifted the burden of production rather than the burden of persuasion. Id., at 513-514. In the proceedings before this Court, the State argued that the Montana Supreme Court’s interpretation of the effect of the presumption was conclusive on this Court. Id., at 516.
This Court unanimously5 rejected the State’s attempt to avoid the constitutional issue by the use of a post hoc narrowing construction by the State’s highest court. While acknowledging that “[t]he Supreme Court of Montana is . . . the final authority on the legal weight to be given a presumption under Montana law, ... it is not the final authority on the interpretation which a jury could have given the [challenged] instruction.” Id., at 516-517 (emphasis added). Instead, this Court defined the relevant question as whether “a reasonable juror could well have been misled by the instruction.” Id., at 517. Even assuming the constitutionality of the Montana Supreme Court’s interpretation of the pre*426sumption, an interpretation that this Court conceded might have been in the minds of “some jurors,” the fact that “a reasonable juror could have given the presumption conclusive or persuasion-shifting effect means that we cannot discount the possibility that Sandstrom’s jurors actually did proceed upon one or the other of these latter interpretations.” Id., at 519 (emphasis added). “Because David Sandstrom’s jury may have interpreted the judge’s instruction as constituting either a burden-shifting presumption ... or a conclusive presumption,” id., at 524, this Court held the instruction unconstitutional and remanded the case to the state courts for proceedings not inconsistent with the opinion.6
In my view, the case presently before the Court presents even a stronger case for rejecting the relevance of an ex post facto saving construction. By certifying this question to the Georgia Supreme Court, the majority concedes that this construction has never been explicitly adopted by the Georgia courts. It must also be acknowledged that petitioner’s interpretation of the jury’s role under the Georgia law is not the only, or even the most plausible, construction of the death penalty statute. A “reasonable juror” could fairly conclude *427that he or she was required to place special emphasis on the existence of statutory aggravating circumstances, and weigh them against each other and against any mitigating circumstances, when deciding whether or not to impose the death penalty. Cf. Godfrey v. Georgia, 446 U. S., at 428-429. Certainly several Members of this Court have operated under this assumption. See Gregg v. Georgia, 428 U. S., at 197-198, 221-222; Godfrey v. Georgia, supra, at 436-437 (Marshall, J., concurring in judgment); Drake v. Zant, 449 U. S. 999, 1001 (1980) (Stewart, J., dissenting from denial of certiorari).
If respondent’s jury subscribed to this interpretation of their role, “their preconceptions were not dispelled by the trial judge’s sentencing instructions.” Godfrey, supra, at 429. Indeed, everything about the judge’s charge highlighted the importance of the aggravating circumstances. Not only were the circumstances submitted to the jury in writing, but also the jury was in turn required to write down each and every aggravating circumstance that it found to be established beyond a reasonable doubt. See Ga. Code § 27-2534.1(c) (1978) discussed supra, at 420. The jury instructions provide absolutely no indication that, after carefully considering each of the statutory aggravating circumstances submitted by the trial judge, the jury should, or even could, discard this list of officially sanctioned grounds for imposing the death penalty in deciding whether to actually sentence respondent to death.
Absent even a shred of evidence that respondent’s' trial judge and jury were cognizant of petitioner’s asserted construction of the Georgia death penalty statute, a construction never acknowledged by any Georgia appellate court, we can only speculate whether “the verdict in this case was not decisively affected by an unconstitutional statutory aggravating circumstance.” 631 F. 2d, at 406. It is precisely to guard against such speculation that this Court has uniformly re*428fused to uphold a conviction or sentence that might have been based even in part on an unconstitutional ground.7 See supra, at 423. Furthermore, in Gregg v. Georgia, supra, at 189, this Court made clear that “where discretion is afforded a sentencing body on a matter so grave as the determination of whether a human life should be taken or spared, that discretion must be suitably directed and limited so as to minimize the risk of wholly arbitrary and capricious action.” See also Furman v. Georgia, 408 U. S. 238 (1972). Because nothing the Supreme Court of Georgia can say in response to this Court’s certification will assure us that respondent’s jury was “suitably directed,”8 I must dissent.
In bench trials, the judge must consider these factors.
To date, the majority of state courts that have confronted this issue have declined to speculate whether the jury would still have returned a death sentence in the absence of the subsequently invalidated aggravating circumstance. See, e. g., Williams v. State, 274 Ark. 9, 11-13, 621 S. W. 2d 686, 687-688 (1981); State v. Irwin, 304 N. C. 93, 106-108, 282 S. E. 2d 439, 448-449 (1981); State v. Moore, 614 S. W. 2d 348, 351-352 (Tenn. 1981); Hopkinson v. State, 632 P. 2d 79, 171-172 (Wyo. 1981). See also Cook v. State, 369 So. 2d 1251, 1255-1257 (Ala. App. 1979).
The States of Alabama, California, Florida, Louisiana, Mississippi, Missouri, Montana, Nebraska, Nevada, North Carolina, South Carolina, and Utah submitted an amicus brief on behalf of petitioner. It is interesting to note that the appellate courts of Alabama and North Carolina have already implicitly rejected the construction now urged by these States as amici. See n. 2, supra.
In my view, if the Georgia Supreme Court adopted this interpretation of the death penalty statute, it would raise serious questions as to the constitutionality of this statute under Gregg.
Justice Rehnquist, joined by The Chief Justice, filed a separate opinion concurring in both the judgment and the opinion of the Court.
The Sandstrom Court also rejected the State’s argument that the jury need not have relied on the challenged instruction in finding Sandstrom guilty of intentional murder. The State reasoned that because the tainted instruction could arguably be viewed as only relating to the defendant’s “purpose,” the jury might have convicted Sandstrom solely on the ground that he “knowingly” caused the death of the victim. Because the statute only requires that the crime be committed “purposefully or knowingly,” the State argued that there was an alternative basis on which the conviction could be sustained. 442 U. S., at 525. Relying on Stromberg v. California, 283 U. S. 359 (1931), this Court refused to engage in such speculation, since “even if a jury could have ignored the presumption and found defendant guilty because he acted knowingly, we cannot be certain that this is what they did do.” 442 U. S., at 526 (emphasis in original). There is similarly no way to tell whether respondent’s jury adopted the Georgia Supreme Court’s yet undisclosed interpretation of the Georgia death penalty statute.
It is irrelevant whether the jury’s determination was only partially based on the presence of the unconstitutional aggravating circumstance. As this Court held in Street v. New York, 394 U. S. 576 (1969), “even assuming that the record precludes the inference that appellant’s conviction might have been based solely on [an unconstitutional ground], we are still bound to reverse if the conviction could have been based upon both” an unconstitutional and a constitutional ground. Id., at 587 (emphasis in original).
The majority’s implication that certifying this case will give the Georgia Supreme Court an opportunity to clarify whether it has the power to “assume the role of the jury when the sentencing jury recommended the death penalty under legally erroneous instructions,” ante, at 415, does not alter my conclusion. In affirming respondent’s death sentence, the Georgia Supreme Court did not purport to exercise such authority. Nor did the State argue that such action by the Georgia Supreme Court was permissible in the proceedings before this Court. Indeed, prior to this Court’s action today, it has always been assumed that “only the trier of fact may impose a death sentence.” Willis v. Balkcom, 451 U. S. 926, 928 (1981) (Marshall, J., joined by Brennan and Stewart, JJ., dissenting from denial of certiorari). In any event, a “reviewing court can determine only whether a rational jury might have imposed the death penalty if it had been properly instructed; it is impossible for it to say whether a particular jury would have so exercised its discretion if it had known the law.” Godfrey v. Georgia, 446 U. S. 420, 437 (1980) (Marshall, J., concurring in judgment).