I respectfully dissent. As I have indicated in my dissenting opinion in the case of People v. Drew, supra, ante, page 333 at page 353 [149 Cal.Rptr. 275, 583 P.2d 1318], I believe that the majority, by repudiating the modified California M’Naghten test of insanity and adopting instead the American Law Institute (ALI) formulation; has invaded the responsibility of the Legislature. Having once committed *432itself to redrafting this area of the law, the majority is now obliged to forge ahead and judicially extend the ALI test to the defense of idiocy, in order to eliminate the inevitable complications which would ensue were different standards to govern the defenses of idiocy and insanity.
In addition to the numerous inadequacies in the ALI test expressed in my Drew dissent, the ALI test does not satisfactorily dispose of the problem, present also in the original M’Naghten formulation, of the dominant role in the case played by expert witnesses who are permitted to testify as to the ultimate fact of criminal responsibility. This result has also been widely criticized, and is illustrated precisely by the present case. Here, the clinical psychologist called by the defense testified that defendant was aware of the nature and quality of his act—the assault upon Hernandez—and that defendant knew that an unprovoked assault upon another person was wrong. However, the psychologist also stated that because of his low intelligence the defendant was extremely susceptible to suggestion and if urged to commit an assault by persons whom he trusted, he would probably believe that the assault was proper.
The original M’Naghten standard provides that “To establish a defense on the ground of insanity it must be clearly proved that, at the time of committing the act, the party accused was labouring under such a defect of reason, from disease of mind, as not to know the nature and quality of the act he was doing; or if he did know it, that he did not know he was doing what was wrong.” (M’Naghten’s Case (1843) 10 Clark & F. 200, 210 [8 Eng.Rep.718, 722].)
Judged by the M’Naghten standard defendant would not be relieved of his criminal responsibility since the testimony of the defense psychologist established that defendant was aware of the nature and quálity of his act and knew that it was wrong. Without any contrary evidence the testimony of the psychologist is fully determinative on the issue of criminal responsibility.
The majority, while decrying what it characterizes as the M’Naghten test’s “stultifying effect upon psychiatric testimony,” (ante, p. 426) here eagerly adopts a test which once again entrenches the expert witness in a position in which his answer to the somewhat different question, regarding the defendant’s ability to conform his actions, will again be virtually dispositive of the issue of criminal responsibility. This fact simply illustrates again that more thought in a legislative forum would produce a better result.
*433As I suggested in Drew, this is an excellent time for us to exercise judicial restraint. Doubtless, proposed legislative changes will embrace the defense of idiocy as well as insanity. We should resist the allure of an instant but questionable resolution of this most troublesome issue and defer to the admittedly slower but undoubtedly more circumspect process of legislation. Our repeated expressions to this effect were correct.
Clark, J., and Manuel, J., concurred.