The defendant, charged with murder in the unlawful killing of one Clarence A. Baker, was convicted of murder in the first degree, and adjudged to suffer death. We have an appeal by him from the judgment.

The only defense was that defendant was insane at the time he killed the deceased. The court correctly instructed the jury, in substance, in view of the settled law of this state, that while it was essential to a conviction that the guilt of the defendant be established to their satisfaction beyond all reasonable doubt except on the single question of insanity, that as to insanity the burden of proof was on defendant, and that it was incumbent on him to show insanity by a preponderance of the evidence before he could be acquitted on that ground. The jury were explicitly and correctly instructed that it was not necessary for defendant to show his insanity beyond all reasonable doubt, but only by a preponderance of evidence, as in civil cases; and also that the proof must be such in amount that if the single issue of sanity or insanity of the defendant should be submitted to a jury in a civil case, they must find him insane—that, in other words, insanity may be established “by a preponderance of evidence merely.” But having so fully and correctly instructed the jury, the learned trial judge gave a further instruction as to what was meant by the term “preponderance of the evidence,” which, so far as we can find, was the only instruction given on the subject. This was as follows, viz.:

The court refused to give an instruction requested by defendant reading in part as follows, and being in all other respects a correct statement of the law:

Defendant’s main contention on this appeal is that the instruction given was erroneous, and we are satisfied that this contention is well based. It is plain to us that the definition thus given by the court was substantially the same as that of proof beyond a reasonable doubt, and that certainly a jury of laymen could find no possible distinction. It is clear that our law contemplates, as does the law generally, a material distinction between the two terms. Always has it been the established rule in this state that proof of guilt beyond all reasonable doubt is essential to the conviction of one of a crime, while a mere preponderance of evidence is sufficient in a civil case, and this rule is expressly stated in section 2061 of our Code of Civil Procedure. The existence of this distinction was fully recognized by the trial judge in this case, who advised the jury as to the necessity of proof of guilt beyond all reasonable doubt, and that defendant was required to prove his insanity only by a preponderance of evidence. The term “reasonable doubt” was fairly enough defined by him, in accord with the definition thereof given by Chief Justice Shaw in Commonwealth v. Webster, 59 Mass. (5 Cush.) 320, [ 52 Am. Dec. 711 ], which has been adopted by the courts of this and practically all other states as the best definition, viz.:

In instructing the jury as to the meaning of the term “proof beyond a reasonable doubt,” the trial judge, in line with this definition, expressly told the jury that “moral certainty only is required or that degree of proof which produces conviction in an unprejudiced mind”; and again, that “the evidence must establish the truth of the fact to a reasonable and moral certainty; a certainty that convinces and directs the understanding, and satisfies the reason and judgment of those who are bound to act conscientiously upon it. ’ ’ Clearly, the jury was thus given substantially the same definition of both the terms “preponderance of evidence” and the term “proof beyond a reasonable doubt,” thus making it essential for the defendant to establish his defense of insanity by evidence showing the same to the satisfaction of the jurors beyond a reasonable doubt. That such is the effect of the instruction given is shown by what is said in People v. Wreden, 59 Cal. 393 , and People v. Wells, 145 Cal. 142 , [ 78 Pac. 470 ], where it is held that an instruction declaring that insanity “must be clearly established by satisfactory proof” is the full equivalent of one making it incumbent on a defendant to establish insanity beyond a reasonable doubt.

No such definition of the term “preponderance of the evidence” as that given by the trial judge is sanctioned by the authorities. The term simply means what it says, viz., that the evidence on one side outweighs, preponderates over, is more than, the evidence on the other side, not necessarily in number of witnesses or quantity, but in its effect on those to whom it is addressed. As good a definition as we have found is that given in Hoffman v. Loud, 111 Mich. 156 , [ 69 N. W. 231 ], where it is said: “In civil cases a preponderance of evidence is all that is required, and by a ‘preponderance of evidence’ is meant such evidence as, when weighed with that opposed to it, has more convincing force, and from which it results that the greater probability is in favor of the party upon whom the burden rests.” In Parker v. Hull, 71 Wis. 368 , [ 5 Am. St. Rep. 224 , 37 N. W. 351 ], it is said that to say that the evidence of one party must be more weighty, convincing, and satisfactory than the proof adduced by the other party is simply to state the rule of preponderance. In French v. Day, 89 Me. 441 , [ 36 Atl. 909 ], it was held that an instruction requiring a “clear preponderance of evidence and convincing proof” was erroneous, and that a party was only required to prove his case “by a preponderance of the evidence,” not by a “clear preponderance and by convincing proof.” In Anderson v. Chicago Brass Co., 127 Wis. 273 , [ 106 N. W. 1077 ], the term is held to be properly defined as the greater convincing power of evidence, and it is said that on a trial that side has furnished the preponderance of evidence which has produced evidence of greater convincing power in the minds of the jury than that produced by the other side. Of course, these definitions do not mean that the “burden of proof” resting on a party to prove a particular fact, as in this case the burden of proof resting on defendant to prove insanity and thus rebut the presumption of sanity which the law declares, is lifted by the mere fact that he has produced a preponderance of evidence, for, as was well said in Ergo v. Merced Falls etc. Co., 161 Cal. 339 , [41 L. R. A. (N. S.) 79, 119 Pac. 103 ], “the evidence tending to prove a fact might be so slight that it would fail to satisfy the jury of the existence of the fact, and yet it might be of greater weight than other evidence introduced which would tend to disprove the fact,” and “that in such a case the fact could not be said to be proven either by a preponderance of the evidence or at all.” The same idea was expressed in Anderson v. Chicago Brass Co., 127 Wis. 273 , [ 106 N. W. 1077 ]. The party on whom rests the burden to prove an alleged fact must produce evidence sufficient in quantity and character to warrant a jury in finding the fact to exist, in the absence of opposing evidence. The question what that evidence must amount to in order to legally support a conclusion by the jury has nothing at all to do with the question what is meant by the term “preponderance of the evidence.” The party on whom rests such burden having produced sufficient evidence to support a conclusion in his favor, opposing evidence'may also have been introduced, and then only does the question of preponderance of evidence arise. The situation may then' be that in view of the opposing evidence, the jury is in doubt, and not at all satisfied or convinced. In such a situation the decision must be based on the preponderance rule. If in the opinion of the jury the testimony preponderates in favor of the one on whom the burden of proof does not lie, or is equally balanced, the decision must be in his favor, and if it preponderates ever so slightly in favor of the other party, he is entitled to a verdict. So that in civil cases a party may have established an essential fact by a preponderance of the evidence,, although, in the light of all the evidence pro and con, the jury may not be satisfied to a moral certainty of the existence of the fact, and the whole evidence may not be such as to produce conviction in their minds. Under such circumstances, as said in Murphy v. Waterhouse, 113 Cal. 467 , [ 54 Am. St. Rep. 365 , 45 Pac. 866 ], “the weight of evidence or preponderance of probability is sufficient to establish a fact in a civil case. ’ ’ The question is not whether, in view of all the evidence, pro and con, the jury are satisfied to a moral certainty of the truth of the fact, or whether conviction as to that fact exists in their minds, but whether there is a preponderance of evidence in favor of the existence of the fact. We cannot avoid the conclusion that the instruction given on this matter most vital to defendant, the only instruction given on the subject, advised the jury that they could not find in his favor on the issue of insanity unless they were satisfied by the evidence, as a whole, “to a moral certainty” that he was insane at the time of the homicide, and “convinced” that such was the case, and we are satisfied that it could have been understood by the jury in no other way.

The error of the learned trial judge in this connection was doubtless induced by certain rather carelessly drawn provisions contained in our Code of Civil Procedure enacted in an attempt to satisfactorily define or declare the degree of proof essential to the establishment of a fact by evidence. (See secs. 1826 and 1835, Code Civ. Proc.) Manifestly these provisions are not in accord with other provisions of law in all respects, even on the subject to which they relate. For instance, in section 1835 it is attempted to declare what is “satisfactory evidence,” defining it as that evidence “which ordinarily produces moral certainty or conviction in an unprejudiced mind”; providing that such evidence alone will justify a verdict, and declaring that all other evidence is “slight evidence.” Yet by other sections of the same code it is declared that a presumption is evidence, and that it is a deduction which the law expressly directs to be made from particular facts, and many presumptions, conclusive and prima facie, are stated, and it is expressly provided that as to a prima facie presumption the jury is bound to find according to the presumption unless it be controverted. Of course, also, it is bound to find in accord with a conclusive presumption. (See secs. 1957,1959, 1961, 1962, and 1963, Code Civ. Proc.) All this is true, although the presumption may not be such as to ordinarily produce moral certainty or conviction of the fact presumed in an unprejudiced mind. But whatever force may be attributed to these sections and whatever they may be held to mean, they have no application to the question here involved, viz., what is meant by the term “preponderance of evidence.” They purport to do no more than to attempt to declare what character of evidence will sustain a verdict, and even in that, as we have seen, when considered in connection with other provisions of law, they are not entirely correct. The instruction given in Ergo v. Merced Falls etc. Co., 161 Cal. 339 , [41 L. R. A. (N. S.) 79, 119 Pac. 103 ], relied on by the attorney-general, was one given at the request of the defendant, which was complaining of another incorrect instruction given at the request of the plaintiff, and it was simply held that the instruction so given at the request of the complaining defendant was of such a nature that the court would not be justified in holding the other instruction sufficiently injurious to justify a reversal. The instruction was not upheld as a correct statement of the law.

We regard the error thus made as one most substantially affecting the rights of defendant. In effect as we have said, the jury was instructed that he could not be acquitted on the ground of insanity unless he established the fact of insanity to their satisfaction beyond a reasonable doubt. We have carefully examined the evidence in order to determine whether, in view of the provisions of section 4% of article VI of the constitution, the judgment should be affirmed notwithstanding such error, and we are satisfied that the evidence was of such a nature that such a conclusion may not fairly be reached. In saying this we do not desire to be understood as intimating that it is our opinion that the jury should have concluded that the preponderance of evidence was in favor of the theory of insanity. The evidence elicited on the trial was of such a nature that a jury might reasonably find therein basis for a conclusion that insanity on the part of the defendant, within the meaning of our law, had not been shown by a preponderance of evidence. But, according to the record, the case made for defendant on this issue was a substantial one, and the evidence tending to show insanity was such that a jury might reasonably have found therein sufficient basis for a conclusion that the preponderance of the evidence was in favor of the theory of insanity. For aught we know the jury did so conclude in this case, finding against the defendant on that issue solely because of the erroneous instruction. It is not suggested by the learned attorney-general that if the instruction be erroneous, the facts nevertheless are such as to warrant an affirmance in view of the rule declared by the provision of the state constitution referred to.

In view of our conclusion on the point discussed, it is unnecessary to consider any other point made for reversal.

We find on an examination of the reporter’s transcript of the proceedings at the trial that the same includes all arguments made by counsel to the court on questions of law arising during the trial. In the aggregate many pages of the transcript are devoted to this use. The incorporation of such arguments in a transcript for use on appeal serves no uséful purpose. To the contrary, it not only impedes the examination of the record by an appellate court, but it also unnecessarily adds to the cost of the transcript to the county. The law does not require the insertion of any such matter in a transcript of the evidence to be used on appeal, and the trial judge should see that such a transcript is not unnecessarily lengthened by the incorporation of superfluous matter.

The judgment is reversed and the cause remanded for a new trial.

Shaw, J., Sloss, J., Melvin, J., Lorigan, J., and Henshaw, J., concurred.