I agree that defendant’s voluntary manslaughter conviction should be affirmed. I write separately because my analysis of the issues presented differs from that set out in the plurality opinion.
*67I
I begin with an examination of the jury’s voluntary manslaughter verdict. Although the plurality declines to decide the issue (plur. opn., ante, at p. 60), the jury’s verdict is clearly supported by the evidence. As this court recently explained in People v. Breverman (1998) 19 Cal.4th 142 [77 Cal.Rptr.2d 870, 960 P.2d 1094] (Breverman), “[b]ecause heat of passion . . . reduce[s] an intentional, unlawful killing from murder to voluntary manslaughter by negating the element of malice that otherwise inheres in such a homicide [citation], voluntary manslaughter of [this] form[] is considered a lesser necessarily included offense of intentional murder [citation].” (Id. at p. 154, original italics, fn. omitted.) “ ‘Under California law, a lesser offense is necessarily included in a greater offense if . . . the greater cannot be committed without also committing the lesser.’ [Citation.]” (Id. at p. 154, fn. 5, italics added.) Thus, by definition, if the evidence is sufficient for a jury to have convicted of the greater offense (here, second degree murder), which everyone agrees that it was (see plur. opn., ante, at pp. 52, 63; see also dis. opn. of Mosk, J., post, at pp. 76, 78), it is necessarily sufficient for a jury to have convicted of the lesser included offense (here, voluntary manslaughter).
Stated somewhat more generally, although a trial court should not instruct on a lesser included offense “when there is no evidence that the offense was less than that charged” (Breverman, supra, 19 Cal.4th at p. 154), it does not follow that if a trial court nonetheless instructs and a jury nonetheless convicts, the conviction of the lesser included offense should be reversed for insufficient evidence. To the contrary, because evidence of the greater offense was sufficient, evidence of the lesser included offense is necessarily sufficient.
An examination of the factual record and the instructions given to the jury in this case leads to the same conclusion. Pursuant to CALJIC No. 8.50, the jury was instructed as follows: “To establish that a killing is murder and not manslaughter, the burden is on the People to prove beyond a reasonable doubt each of the elements of murder and that the act which caused the death was not done in the heat of passion or upon a sudden quarrel.”1 Pursuant to CALJIC No. 8.72, the jury was also instructed as follows: “If you are *68satisfied beyond a reasonable doubt that the killing was unlawful but you have a reasonable doubt whether the crime is murder or manslaughter, you must give the defendant the benefit of such doubt and find it to be manslaughter rather than murder." Here, as the Court of Appeal observed, "[w]hile defendant was clearly provoked, there is no evidence in this record upon which the trier of fact could rationally assess whether the provocation was sufficient to cause the average person to have acted similarly."2 Viewed in this light, the jury's voluntary manslaughter verdict reflects nothing more than its conclusion that the prosecution failed to carry its assigned burden of negating heat of passion beyond a reasonable doubt.3
II
Nor do the involuntary manslaughter instructions given to the jury provide a basis for reversing defendant’s voluntary manslaughter conviction. The plurality holds that the trial court erred when it failed to instruct sua sponte on a misdemeanor manslaughter theory of involuntary manslaughter. (Plur. opn., ante, at pp. 60-61.) According to the plurality, such instructions were warranted because “when defendant used his gun in the quarrel with [his wife] he violated [Penal Code] section 417, subdivision (a)(2), committing the misdemeanor offense of ‘brandishing’ a weapon.” (Plur. opn., ante, at p. 61.) The plurality then proceeds to deem the error harmless. (Id. at pp. 62-63.)
This case demonstrates, yet again, the pitfalls of requiring trial courts to instruct sua sponte on lesser included offenses. (See Breverman, supra, 19 Cal.4th at pp. 195-202 (dis. opn. of Brown, J.).) As a legal matter, requiring sua sponte instructions on involuntary manslaughter, on a misdemeanor manslaughter theory, on a “brandishing” subtheory, demands that our trial judges be psychic. And, as a factual matter, I question whether such instructions were warranted in this case. As noted above, a trial court should not *69instruct on a lesser included offense “when there is no evidence that the offense was less than that charged.” (Breverman, supra, 19 Cal.4th at p. 154.) Here, it is doubtful whether a rational jury could have found that brandishing—and only brandishing—occurred. It appears that at a bare minimum, when defendant used his gun during the quarrel with his wife, he committed felony assault. (Cf. People v. Lipscomb (1993) 17 Cal.App.4th 564, 569-570 [21 Cal.Rptr.2d 445].) Under these circumstances, I would not require the trial court to have instructed sua sponte on the misdemeanor manslaughter theory of involuntary manslaughter.4
IH
For the reasons discussed above, I agree that defendant’s voluntary manslaughter conviction should be affirmed.
CALJIC No. 8.50 is based on the United States Supreme Court’s decision in Mullaney v. Wilbur (1975) 421 U.S. 684 [95 S.Ct. 1881, 44 L.Ed.2d 508] (Mullaney). (See com. to CALJIC No. 8.50 (6th ed. 1996) p. 437.) In Mullaney, the high court held that “the Due Process Clause requires the prosecution to prove beyond a reasonable doubt the absence of the heat of passion on sudden provocation when the issue is properly presented in a homicide case.” (421 U.S. at p. 704 [95 S.Ct. at p. 1892].) This court has yet to address whether the Mullaney holding governs California’s statutory scheme proscribing unlawful homicides. (See Breverman, supra, 19 Cal.4th at p. 170, fn. 19 [declining to address the issue]; see also id. at *68pp. 201-202, fh. 4 (dis. opn. of Brown, J.) [same].) I express no opinion on that question here. For the present purposes, it is sufficient to note that the instruction requiring the prosecution to negate heat of passion beyond a reasonable doubt inured to defendant’s benefit.
Defendant’s daughter testified that she saw her parents arguing and pushing each other, but that she could not hear what they were saying.
The plurality cites People v. Williams (1969) 71 Cal.2d 614, 624 [79 Cal.Rptr. 65, 456 P.2d 633] (Williams), for the proposition that “[a]dequate provocation and heat of passion must be affirmatively demonstrated.” (Plur. opn., ante, at p. 60.) This proposition is based on Williams’s statement that “[m]alice is presumed and the burden is on [defendant] ‘to raise a reasonable doubt in the minds of the jurors that malice was present.’ [Citations.]” (Williams, supra, 71 Cal.2d at p. 624.) Similarly, Justice Mosk’s dissenting opinion cites Williams and other decisions of this court for the proposition that provocation is an element of voluntary manslaughter. (See dis. opn. of Mosk, J., post, at p. 75, fn. 2.) We have yet to reconcile these decisions with the United States Supreme Court’s decision in Mullaney. (See ante, fn. 1.)
Having concluded that sua sponte instructions were required, the plurality goes on to deem the failure to so instruct harmless. (Plur. opn., ante, at pp. 62-63.) The plurality’s harmless error analysis is based primarily on the fact the jury convicted defendant of voluntary manslaughter, a greater offense of involuntary manslaughter. (See id. at p. 63 [“The jury had been instructed three times that it must find intent to kill in order to return a verdict of voluntary manslaughter. The evidence supported such a finding. We conclude on that basis that the error in failing to instruct on misdemeanor manslaughter was not prejudicial.” (Fn. omitted.)].) In other words, the failure to instruct on the lesser included offense was harmless because the jury convicted defendant of a greater offense. Once again, “I wonder why, if the sua sponte instruction rule is as important as some of our prior cases seem to say, we have now made the failure to instruct on lesser included offenses all but harmless per se. [Citation.]” (Breverman, supra, 19 Cal.4th at p. 195, fn. 1 (dis. opn. of Brown, J.).)