OPINION OF THE COURT BY
LUM, CJ.This court is called upon to reverse a criminal conviction for abuse of a family or household member, in violation of Hawaii Revised Statutes § 709-906 (1985). The error claimed is that, in a bench trial, the judge’s ruling included a statement indicating that she was using an erroneous standard for the prosecution’s burden of proof. As appellate courts must be firmly convinced that the trial court used the correct standard, we reverse.
*297I.
Appellant and her boyfriend (now spouse), lived together at the time of the alleged abuse. When the police arrived, the boyfriend had a cut on his forehead and told the police that appellant had thrown and struck him with a VCR. The boyfriend put that in writing on an HPD Form 252.
Appellant and her boyfriend married two days prior to the trial. At the trial, the boyfriend told the court that he had tripped on a recliner and struck his head on a coffee table. Appellant told the same story.
In ruling, the judge discredited their testimony, stating that it was obvious that the boyfriend was merely protecting his new wife. However, in its general finding the court stated that:
[TJhere is sufficient substantial credible evidence to adjudge the Defendant guilty of the offense of Abuse of a Household Member.
On appeal, appellant raises the issue of whether the judge applied the proper standard of proof.
II.
There is no question but that the burden of proof for the prosecution in a criminal case is that guilt must be proved beyond a reasonable doubt. In re Winship, 397 U.S. 358, 364, 90 S. Ct. 1068, 1073, 25 L. Ed. 2d 368, 375 (1970). The standard is defined as:
Such proof as precludes every reasonable hypothesis except that which it tends to support and which is wholly consistent with defendant’s guilt and inconsistent with any other rational conclusion.
Black’s Law Dictionary 1215 (6th ed. 1990). Substantial evidence, however, is defined as:
*298Evidence which a reasoning mind would accept as sufficient to support a particular conclusion and consists of more than a mere scintilla of evidence but may be somewhat less than a preponderance.
Id. at 1428. Clearly, the substantial evidence standard is not adequate to support a finding of guilty in a criminal case.
III.
The real question is whether “substantial credible evidence” is the standard which the judge actually applied, or whether it was merely a slip of the tongue. Concededly, there are strong arguments both ways.
First, this court could read between the lines, and determine that the judge was using the proper standard. At least one court has “independently applied the proper standard of proof.” Giles v. State, 554 So. 2d 1073, 1089 (Ala. Crim. App. 1984), affd in part, rev’d in part on other grounds sub nom Ex Parte Giles, 554 So. 2d 1089 (1987). We recently addressed the issue where the argument was put forth that the wrong standard of proof was applied. In a disciplinary case which was subject to a recently mandated change in the burden of proof, but there was no statement by the ruling body as to what standard was applied, we nevertheless reviewed the record to see if it supported the findings and conclusions of the Disciplinary Board, using the proper burden. Office of Disciplinary Counsel v. Rapp, 70 Haw. 539, 777 P.2d 710 (1989). In that case there was no statement by the ruling body; the instant case provides this court with such a statement.
We find the ruling by this court in an earlier case to be the better rule to follow where such a statement is made. In State v. Matsuda, 50 Haw. 128, 432 P.2d 888 (1967), this court reversed the judgment where the trial judge found that the defendant “failed to convince the court that the defendant suffered a black out....” *299Id. at 128-29, 432 P.2d at 890. We held that defendant’s burden of proof is merely to raise a reasonable doubt in the mind of the trial judge, not to convince him of his defense. Id. at 129, 432 P.2d at 890. We refused there to speculate as to what legal test the trial judge actually applied, taking the statement at face value.1
To argue that there is substantial evidence to convict is really arguing that the error was harmless. As the error claimed is of constitutional dimension, before it can be held harmless, “the court must be able to declare a belief that it was harmless beyond a reasonable doubt.” Chapman v. California, 386 U.S. 18, 24, 87 S. Ct. 824, 828, 17 L. Ed. 2d 705, 711 (1967) (followed by this court in State v. Napeahi, 57 Haw. 365, 373, 556 P.2d 569, 574 (1976)). The fact that we are divided convinces us that the standard has not been met.
Rule 23(c) of the Hawaii Rules of Penal Procedure (HRPP) dictates that in a bench trial the court need only make a general finding unless special findings are requested.
In a case tried without a jury the court shall make a general finding and shall in addition, on request made at the time of the general finding, find such facts specially as are requested by the parties. Such special findings may be orally in open court or in writing at any time prior to sentence.
HRPP Rule 23(c).
As Rule 23(c) only requires that a general finding be made, the statement made by the judge leaves us confused as to what *300standard of proof was being applied. Since we are not convinced that the judge used the proper standard, that guilt must be proved beyond a reasonable doubt, we reverse for a new trial.
Judd Scott (Theodore Y.H. Chinn on the brief), Deputy Public Defenders, for defendant-appellant. Joseph W. Lee, Deputy Prosecuting Attorney, for plaintiffappellee.The dissent takes issue with the holding of Matsuda insofar as it suggests that defendant has any burden of proof. The criticism is well placed, but makes the ultimate holding of Matsuda, that the proper standard of proof must be applied, even more compelling in this case. We find State v. Cannon, 56 Haw. 161, 532 P.2d 391 (1975), cited in the dissent as an erosion of Matsuda, to be distinguishable in that the error complained of in Cannon was not of constitutional dimension, as it was not the final determination of guilt.