This is a proceeding for writ of mandate to compel respondent court to set aside and vacate its order granting a new trial. The ease is a companion to
Mercer
v.
Perez,
ante, p. 104 [
Petitioner is the plaintiff in a damge action filed in respondent court against the real party in interest. On January 18, 1967, the jury in that action returned a verdict in favor of petitioner; counsel for petitioner fails to so advise us, but we presume judgment was entered in due course. On March 21, respondent court denied a motion for judgment notwithstanding the verdict but granted a motion for new trial. As to the latter the order recited simply, “Motion for new trial granted—errors in law.” On April 7 petitioner filed a notice of motion to vacate the new trial order on the ground that it was void for failure of the court to specify its “reason or reasons” in compliance with Code of Civil Procedure section 657, as amended in 1965. 1 The motion was *131 denied on May 10, and two days later petitioner filed an application for writ of mandate in the Court of Appeal, seeking to compel respondent court to vacate its new trial order on the just-mentioned ground. The application was denied without opinion on May 17, and a petition for hearing was presented to this court. In view of the importance to the bench and bar of a speedy and authoritative construction of these new statutory provisions, we issued an alternative writ and set the matter for hearing at the same time as Mercer.
Using the statutory language, the new trial order here entered adequately states the ground, “errors in law,” upon which it was granted. But the order wholly fails to comply with the further requirement of section 657 that the court shall specify its “reason or reasons for granting the new trial upon each ground stated.” In Mercer we explain that the dual statutory intent underlying this requirement is to encourage careful deliberation by the trial courts before ordering new trials and to promote a more meaningful appellate review of such orders; to effectuate these purposes, we there hold (ante, p. 113) that if the ground of the order is insufficiency of the evidence, the judge must briefly recite the respects in which he finds the evidence to be legally inadequate. Upon the same considerations, we now hold that if the ground is “errors in law” the statute requires the judge to briefly specify the errors that are the basis for his ruling. For example, if the error is improper admission or exclusion of evidence, the judge should so state and should identify the evidence in question; if the error is the giving of incorrect instructions, the judge should again so state and should point out the instructions on which he reversed himself.
Petitioner urges that the requirement of “reasons” be extended to demand of the trial judge an explanation why he was of the opinion that a given error of law was prejudicial. (Cal. Const., art. VI, § 13.) It would be unreasonable, however, to construe section 657 as compelling the judge to set forth his “examination of the entire cause, including the evidence,” on the face of the new trial order itself. Moreover, even if such an explanation were furnished it would not
*132
be binding on, the reviewing court. ■ ■ On an appeal from an order granting a new trial, that court has the power to determine as a question of law whether any challenged ruling below was erroneous; but once such an error is shown, the reviewing court may not substitute its judgment for that of the trial court on the essentially factual question of prejudice. At this point the issue is not whether the reviewing court would find the error to be prejudicial as an original matter, nor even whether the particular explanation offered by the trial court supports the finding of prejudice; the sole issue is whether the order granting a new trial, viewed in the light of the whole record, constituted a manifest abuse of discretion.
(Brandelius
v.
City & County of San Francisco
(1957)
Here, as in Mercer, our most difficult problem is the • proper disposition of the case. Petitioner contends that the failure to specify reasons in compliance with section 657 renders the order void and in excess of jurisdiction, and hence that mandate will lie to compel respondent court to vacate it. It is true that in a number of cases procedural errors in making and determining a motion for new trial have been held jurisdictional and reached by way of extraordinary writ. (See, e.g.,
Tabor
v.
Superior Court
(1946)
No such jurisdictional defect appears in the order now before us: although the court did not specify the reasons for the ruling, it was timely made upon a proper motion served on the adverse parties. As we explain in Mercer, such an order is not in excess of jurisdiction.
This conclusion is rendered unassailable by the circumstance that in the present ease the ground on which the motion was granted was “errors in law.” In adjudicating an appeal from a new trial order predicated on that or any ground other than insufficiency of the evidence or excessive or inadequate damages, the reviewing court is governed by the fourth paragraph of the 1965 amendments to section 657: codifying the common-law rule in this respect (see
Kauffman
v.
Maier
(1892)
Under this rule we have deemed ourselves bound to affirm a new trial order upon an error in law which was not only not the ground specified by the trial judge, but was apparently not even within his contemplation at the time of his rul
*134
ing.
(Malkasian
v.
Irwin
(1964)
This does not mean, however, that relief by way of mandate is ipso facto rendered unavailable. Although petitioner is not entitled to a writ compelling respondent court to vacate its order and reinstate the judgment, mandate does not reach void orders only. We now turn to the question Avhether petitioner is entitled to compel the court at least to specify its reasons for granting a new trial on the stated ground of errors in law. Such specification, under the amended section 657, is “an act which the law specially enjoins, as a duty resulting from an office” (Code Civ. Proc., § 1085), and hence would appear to be within the scope of the remedy.
But it has been judicially established that the applicant for a writ of mandate must also show that the respondent has a
present
duty to perform the act he seeks to compel. (See
County of Sacramento
v.
Hickman
(1967)
It appears from the face of the present petition that respondent court no longer has the power to perform the act here sought to be compelled. The order granting a new trial was made on March 21, 1967; the third paragraph of the 1965 amendments to section 657 (ante, fn. 1) provides that *135 when, as here, the order does not contain the reasons, “the court must, within 10 days after filing such order,” file a separate specification of reasons in writing. We hold in Mercer (ante, p. 121) that the prescribed 10-day period is a statute of limitations on the authority of the court to act, and that after the expiration of the period the court has no power to add a specification of reasons by a nunc pro tunc order or otherwise. As the 10-day period in the case at bar expired on March 31, 1967, respondent court has no further jurisdiction over the matter which it could be compelled to exercise by writ of mandate.
A persuasive analogy is found in
Daniels
v.
Superior Court
(1955)
Nor has petitioner demonstrated that he lacks a plain, speedy, and adequate remedy by way of appeal. (Code Civ. Proc., § 1086.) We hold in
Mercer
that a new trial order supportable only on the ground of insufficiency of the evidence (or excessive or inadequate damages) will be reversed if the trial court has failed to specify its reasons for so ruling; upon analysis, it will be seen that when a new trial order is made without specification of reasons on any other ground, an appeal therefrom may nevertheless prevail. Petitioner argues that the remedy is inadequate because the main purpose of the new requirement of specification of grounds and reasons is to provide the basis for such an appeal by apprising the reviewing court of the intent of the court below; but as the statute itself requires the reviewing court to consider all the grounds listed in the motion and not merely those relied upon by the trial court, the argument lacks persuasive force. It is true that the scope of review in such circumstances will encompass the entire record; but if for example the only available ground is ‘ ‘ errors in law, ’ ’ as may well be the case here,
4
and the appellant shows there were no such errors at the trial, the order will be reversed (see, e.g.,
Reusche
v.
California Pac. Title Ins. Co.
(1965)
In conclusion, the first paragraph of the 1965 amendments to section 657 places on the trial courts a clear and unmistakable duty to furnish a timely specification of both their grounds and their reasons for granting a new trial, and we expect that such duty will be faithfully discharged. But in the event of inadequate specification in either respect, the fourth paragraph of the amendments nevertheless requires *137 that the new trial order he affirmed on appeal if it should have been granted on any ground stated in the motion, except insufficiency of the evidence or excessive or inadequate damages. There is no conflict in these provisions; different legislative purposes are served by each, and both must be given the fullest effect possible.
The alternative writ of mandate is discharged and the peremptory writ is denied.
Traynor, C. J., McComb, J., Peters, J., Tobriner, J., Burke, J., and Sullivan, J., concurred.
Notes
Insofar as here relevant, the 1965 amendments to section 657 (Stats. 1965, eh. 1749, p. 3922) provide:
[ 1st par.] “When a new trial is granted, on all or part of the issues, the court shall specify the ground or grounds upon which it is granted and the court’s reason or reasons for granting the new trial upon each ground stated.
[ 3d par.] “The order passing upon and determining the motion must be made and entered as provided in Section 660 and if the motion is granted must state the ground or grounds relied upon by the court, and may contain the specification of reasons. If an order granting such motion does not contain such specification of reasons, the court must, within 10 days after filing such order, prepare, sign and file such specification of reasons in writing with the clerk. The court shall not direct the attorney for a party to prepare either or both said order and said specification of reasons.
[ 4th par.] “On appeal from an order granting a new trial the order shall be affirmed if it should have been granted upon any ground stated in the motion, whether or not specified in the order or specification of reasons; ...”
The statute was again amended in 1967 to add “inadequate damages” as a ground for granting a new trial, and in respects not here quoted its language was slightly modified to reflect the change. (Stats. 1967, *131 eh. 72, § 1.) The present proceeding does not involve any issue of damages, however, and for the sake of clarity we shall discuss the statute in its 1965 version in the remainder of this opinion, except where otherwise indicated.
The phrase, ‘ ‘ or specification of reasons, ’ ’ appears to be surplusage, as the preceding paragraph of the statute clearly requires that the grounds of the ruling (as opposed to its reasons) “must” be stated in the order itself.
Although the facts turned out to be quite different when the record was brought up on a subsequent appeal
(Daniels
v.
Daniels
(1956)
That was the ground of the present order, and petitioner has not informed us whether there were other grounds listed in the notice of motion. On May 19, 1967, petitioner filed a notice of appeal from the new trial order, and on June 5 the real party in interest filed a notice of cross-appeal from the judgment. We intimate no opinion as to the status or merits of those appeals.
