with whom The Chief Justice joins, concurring.
While I join in the Court’s opinion, the somewhat peculiar posture of the case as it comes to us leads me to add these observations.
Respondent made no objection to the trial court’s instruction respecting the burden of proof on the issue of whether he had acted in the heat of passion on sudden provocation. Nonetheless, on his appeal to the Supreme Judicial Court of Maine, that court considered his objection to the charge on its merits and held the charge to be a correct statement of Maine law. It neither made any point of respondent’s failure to object to the instruction in the trial court,* nor did it give any consideration to the doctrine long approved by this Court that the *705instructions to the jury are not to be judged in artificial isolation, but must be viewed in the context of the overall charge. Boyd v. United States, 271 U. S. 104, 107 (1926); Cupp v. Naughten, 414 U. S. 141, 147 (1973). It likewise expressed no view on whether, even though the instruction might have amounted to constitutional error, that error could have been harmless. Chapman v. California, 386 U. S. 18 (1967). Its reason for not treating the possibility that the error was harmless may have been because, as this Court’s opinion points out, ante, at 687, the jury came back in the midst of its deliberations and requested further instructions on the doctrine of implied malice aforethought and the definition of “heat of passion.”
The case which has now reached us through the route of federal habeas corpus, therefore, is a highly unusual one which does present the abstract question of law isolated by the Supreme Judicial Court of Maine and now decided here.
I agree with the Court that In re Winship, 397 U. S. 358 (1970), does require that the prosecution prove beyond a reasonable doubt every element which constitutes the crime charged against_a defendant. T see nb~mcdnsistehcyrb“etween that holding and the holding of Leland v. Oregon, 343 U. S. 790 (1952). In the latter case this Court held that there was no constitutional requirement that the State shoulder the burden of proving the sanity of the defendant.
The Court noted in Leland that the issue of insanity as a defense to a criminal charge was considered by the jury only after it had found that all elements of the offense, including the mens rea, if any, required by state law, had been proved beyond a reasonable doubt. Id., at 792, 795. Although as the state court’s instructions in Leland recognized, id., at 794-795, evidence relevant *706to insanity as defined by state law may also be relevant to whether the required mens rea was present, the existence or nonexistence of legal insanity bears no necessary relationship to the existence or nonexistence of the required mental elements of the crime. For this reason, Oregon’s placement of the burden of proof of insanity on Leland, unlike Maine’s redefinition of homicide in the instant case, did not effect an unconstitutional shift in the State’s traditional burden of proof beyond a reasonable doubt of all necessary elements of the offense. Id., at 795. Both the Court’s opinion and the concurring opinion of Mr. Justice Harlan in In re Winship, supra, stress the importance of proof beyond a reasonable doubt in a criminal case as “bottomed on a fundamental value determination of our society that it is far worse to convict an innocent man than to let a guilty man go free.” 397 U. S., at 372 (Harlan, J., concurring). Having once met that rigorous burden of proof that, for example, in a case such as this, the defendant not only killed a fellow human being, but did it with malice aforethought, the State could quite consistently with such a constitutional principle conclude that a defendant who sought to establish the defense of insanity, and thereby escape any punishment whatever for a heinous crime, should bear the laboring oar on such an issue.
While Fay v. Noia, 372 U. S. 391 (1963), holds that a failure to appeal through the state-court system from a constitutionally infirm judgment of conviction does not bar subsequent relief in federal habeas corpus, failure to object to a proposed instruction should stand on a different footing. It is one thing to fail to utilize the appeal process to cure a defect which already inheres in a judgment of conviction, but it is quite another to forgo making an objection or exception which might prevent the error from ever occurring. Cf. Davis v. United States, 411 U. S. 233 (1973). Here, however, the Maine Supreme Judicial Court nevertheless affirmatively ruled that the issue was cognizable despite respondent’s failure to object at trial. See majority opinion, ante, at 688 n. 7. And the State did not contest the propriety of consideration of the issue in federal habeas.