¶1(concurring in part) — I have signed the court’s opinion and concur in all of it except that part which purports to predict a future overruling of Lankford v. Tombari, 35 Wn.2d 412, 213 P.2d 627, 19 A.L.R.2d 462 (1950), a case which held that proof of drug addiction is relevant to credibility. The rule admitting such evidence cuts both ways, and it is available to both defense and prosecution and I think should be retained. When the prosecution is compelled by the force of circumstances to rely upon the testimony of narcotic addicts to establish guilt, the defendant in all fairness should be permitted to show the addiction as a factor in assessing credibility.
¶2In tampering with the Lankford v. Tombari rule, the court, I think, makes four errors: First, it overrules a long-established precedent when it need not do so in order to reach an otherwise sound decision; second, it predicts the future actions of this court on a question of law not now before it; third, it suggests that proof of drug addiction may be rendered relevant and admissible if the court will only *741halt the trial and take a collateral excursion into the field of medicine and psychology to try the general issue of drug addiction as it affects one’s veracity; and fourth, it departs from the long-established common-law technique of handling appeals in order to prophesy that this court will, when the point is directly in issue, categorically hold inadmissible evidence of drug addiction unless a collateral trial is held, and it implies that in a future case proof of drug addiction must be excluded unless the evidence preponderates in the particular case on trial that drug addicts are inclined to falsehood. When the court ruled in the instant case that proof of defendant’s drug addiction became relevant and admissible because she voluntarily put her character in issue, that should have been the end of the matter. Its discussion of the ramification of Lankford v. Tombari, supra,both was unnecessary to a decision in this case and will probably lead to a wrong conclusion when the point is examined again.
¶3If the facts of this case, however, can be said to necessarily evoke a discussion of the Lankford v. Tombari precedent, requiring that it either be followed or overruled in order to reach a decision in the instant case, I would adhere to Lankfordbecause, in my judgment, it declares the better rule. To require expert testimony that drug addiction does affect one’s truthfulness before allowing evidence of it creates a collateral issue of fact not germane to the genuine issues on trial, and substitutes the opinion of experts for the commonsense of the jury. It is the court’s prerogative to rule upon the admissibility of evidence and the jury’s to decide its weight and effect; the court rules as a matter of law and the jury decides as a matter of fact. Now the court converts an issue of law into an issue of fact, a process which will frequently, I think, produce ludicrous results. In some cases, in the same courthouse, the evidence, because of expert testimony, will be rendered admissible while across the hall the same issue will be resolved differently as a matter of fact and the identical evidence rendered inadmissible.
¶4*742This court’s opinion in Lankfordthat proof of drug addiction is admissible as a matter of law left to the jury to decide what weight, if any, should be given it. That proposition, I think, rests on a sound rationale, authoritatively supported. 3A J. Wigmore, Evidence § 934 (Chadbourn rev. 1970), states the principle correctly:
Any diseased impairment of the testimonial powers, arising from whatever source, ought also to be considered:
Accordingly, the morphine or other drug habit, in that it may have had such an effect, should be received.
¶5(Footnote omitted.)
¶6The rule allowing proof of drug addiction as a factor to be weighed in assessing credibility has withstood the test of time. For example, in 1916, the Supreme Court of Idaho, in a widely cited opinion, passed directly upon the issue when a dying declaration was put in evidence in a murder prosecution. The victim, a Chinese unfamiliar with the English language, had made the dying declaration in Chinese. It was held admissible when introduced through an interpreter. To test the credibility and competency of the witness who had related the declaration, defendant asked on cross-examination, “Isn’t it a fact that you are an habitual user of opium?” The trial court sustained an objection to the question. On defendant’s appeal, however, the Supreme Court of Idaho reversed, holding that evidence of the fact that the witness was an opium user was admissible as relevant to his competency and credibility, saying:
We believe it will be admitted that habitual users of opium or other like narcotics, become notorious liars.
. . . But we do mean to hold that the habitual use of morphine, cocaine and other like narcotics, which inevitably tend to impair the mind, destroy the memory and moral character of a witness, may be shown for the purpose of affecting his credibility or the weight that should be given to his testimony.
¶7*743State v. Fong Loon, 29 Idaho 248, 258-60, 158 P. 233 (1916). Accord, Chicago & N.W. Ry. v. McKenna, 74 F.2d 155 (8th Cir. 1934); Wilson v. Thurston Nat’l Ins. Co., 251 Ark. 929, 475 S.W.2d 881 (1972).
¶8Accordingly, I think we should leave well enough alone. Lankford v. Tombari, supra,is not now before us and I would not gratuitously repudiate it either collaterally or directly.
¶9Hamilton, J., concurs with Hale, C. J.
¶10(dissenting) — At first blush, it may seem that the basic thesis of the majority opinion places this court in line with modern authority on the law of evidence which excludes evidence as to drug usage or addiction for character impeachment purposes. But this would not be an accurate characterization of the majority opinion for reasons indicated hereinafter.
¶11The majority indicates that exclusion of drug evidence relating to testimonial capacity is warranted and as to reasons for exclusion states “[i]n view of society’s deep concern today with drug usage and its consequent condemna*744tion by many if not most, evidence of drug addiction is necessarily prejudicial in the minds of the average juror.” (Italics mine.) Had the majority halted at this juncture, I would find myself in general agreement on this issue. However, the majority retreats from the indicated position and proceeds to condone admission of the concededly prejudicial evidence, curiously enough on the ground of moral character impeachment. Such a fine distinction regarding the law of evidence in such a sensitive area may find solace and acceptance in some quarters. But the attempted distinction is simply too unrealistic to withstand careful analysis. First, all character evidence, positive or negative, is designed to accomplish the same result — to establish the relative credibility of the witness. See generally C. McCormick, The Law of Evidence § 41 (2d ed. E. Cleary 1972); 3A J. Wigmore, Evidence § § 920-22 (J. Chadbourn rev. 1970). Hence, when any evidence is offered which bears upon the character of a witness, it is, in effect, supposed to say to the jury, “ladies and gentlemen, on the basis of this evidence, you are to give greater [or less] credence to the testimony of the witness.” The legitimate or legal purpose of character evidence is to give the triers of fact a proper perspective upon the trustworthiness of a witness’ testimony. Thus, character evidence, either of a supportive or impeaching nature, must relate to the general trait of credibility.
¶12Secondly, character impeachment may be broken down into two types: (1) that of impeachment based upon capacity, and (2) impeachment upon a moral ground. The former category relates to instances where the witness is lacking in testimonial capacity due to insanity, intoxication, disease or other infirmities. In the absence of expert testimony to the contrary, the majority would not allow the introduction of evidence of former drug usage as bearing upon the witness’ capacity for truthtelling, nor would I. The second category embraces impeachment based upon a *745lack of moral character which could affect the witness’ credibility in the matter being litigated. Thus, for example, a prosecutrix in a rape case may be impeached by a prior history of prostitution. See generally 3A J. Wigmore, supra §§ 920-30. The majority appears to hold that evidence of a former drug habit or experience may be admitted to counter defense evidence of good character.
¶13Finally, there is evidence which may be excluded from permissible character impeachment because its highly prejudicial nature outweighs its probative value. Thus, evidence of misconduct or criminal convictions is often excluded from the prosecutor’s impeachment of character if admission of such evidence would unduly prejudice the jury. See 3A J. Wigmore, supra; C. McCormick, supra, §§ 42-43. For reasons elaborated hereinafter, evidence of former drug addiction should not be considered or allowed to play a role in moral character impeachment. Such evidence should be excluded on policy grounds due to its highly prejudicial nature.
¶14In analyzing the intricacies of the law of evidence, complex nuances cannot be allowed to become distracting and misleading. Again, the sole object of character impeachment is to weaken the credibility of the witness in the eyes *746of the jury. It is not the purpose of character impeachment to allow a wide-ranging evidentiary assault upon a witness in an effort to convince the jury that the witness is a nonconformist as to acceptable social mores. That unworthy ploy should be correctly termed character assassination, not character impeachment. Thus, to comply with the oft forgotten goals of proper character impeachment, evidence must be constrained and limited to the admission of evidence which clearly bears upon credibility.
¶15Impeachment Of Character Or Credibility Based Upon The Witness’ Lack Of Capacity
¶16It seems to me the majority confuses the capacity and moral components of character impeachment which, as noted, are necessarily subsumed subcategories of character or credibility impeachment. As to the problem of a witness’ lack of capacity, there is a chronological split of authority. Some courts would admit and others would exclude evidence of drug usage to impeach credibility based upon incapacity. See 3A J. Wigmore, supra at §§ 931-40. See also cases collected in 3A J. Wigmore, supra at § 934 n.1; Annot., 52 A.L.R.2d 848 (1957, Supps. 1967, 1973); Comment, 16 S. Calif. L. Rev. 333 (1943). The schism separating the courts may well be a product of the prevailing societal attitude, at the time of trial, concerning drug addiction. Thus, many of the early courts took the position that as a matter of common knowledge “[t]he habitual use of opium ... is known to utterly deprave the victim of its use and render him unworthy of belief.” State v. Concannon, 25 Wash. 327, 335, 65 P. 534 (1901). Another approach characterized by Wigmore as the “dream theory state” finds its expression in State v. Fong Loon, 29 Idaho 248, 258, 158 P. 233 (1916), “The habit of lying comes doubtless from the fact that the users of those narcotics pass the greater part of their lives in an unreal world, and thus become unable to distinguish between images and facts, between illusions and realities.” Many of the early courts based their opinion that drug usage necessarily led to pathological lying upon contemporary and ostensibly competent medical authority. See, e.g., *747State v. Fong Loon, supra; Effinger v. Effinger, 48 Nev. 205, 228 P. 615, 239 P. 801 (1925). See also Wharton & Stille, Medical Jurisprudence § 1111 (5th ed. 1905). However, time and the healing arts change, and mendacity or truthtelling as an inevitable consequence of drug addiction is no longer a medical truism. See generally Note, Testimonial Reliability of Drug Addicts, 35 N.Y.U.L. Rev. 259 (1960); Note, 1966 Utah L. Rev. 742.
¶17The landmark case of Kelly v. Maryland Cas. Co., 45 F.2d 782 (W.D. Va. 1929), aff'd, 45 F.2d 788 (4th Cir. 1930), is the progenitor of the modern line of authority which rejects the contention that drug addiction, in itself, ineluctably yields untruthfulness. In a scholarly opinion, the Kellycourt would, however, follow the suggestion of Wigmore and allow expert testimony to establish the possible impairment of a witness’ faculties through drug use.
¶18The decision of when to allow expert testimony bearing upon truth or veracity was squarely faced by the New York Court of Appeals in People v. Williams, 6 N.Y.2d 18, 159 N.E.2d 549, cert. denied, 361 U.S. 920, 4 L. Ed. 2d 188, 80 S. Ct. 266 (1959). In Williams, the New York court surveyed the current medical literature in a well-reasoned decision and concluded:
[I]t is only after long and serious deliberation that we hold inadmissible expert testimony that narcotics addicts of the same type as a witness are unworthy of belief in the absence of a clear and convincing showing to the full satisfaction of the Trial Judge that such is the consensus of medical and scientific opinion. The reliability of such a thesis must be clearly established before a jury may be subjected to its influence.
¶19People v. Williams, supra at 26.
¶20Thus, synthesizing the salient reasoning of the Kellyand Williamscourts, I concur with the majority that the better rule is to allow expert testimony relating to the effects of drug usage when it involves the impairment of the witness’ faculties.
¶21*748Impeachment Of Character Or Credibility On Moral Grounds
¶22The majority, contrary to the weight of modem authority, however, would allow testimony of former drug usage to impeach the defendant’s character where there has been a minimal offer of good character evidence by the defense. This, of course, does not relate to the capacity component, but to the moral component of character impeachment, i.e., the witness’ truthfulness or mendacity. See 3A J. Wigmore, supra at §§ 920-30.
¶23But the majority, I think, has proven too much. It has conceded that there is no established link between drug addiction and the witness’ proclivity for truthtelling. Nor does there exist in established jurisprudence the suggested “alternative and more restrictive ground of character impeachment” as all impeachment on moral grounds is necessarily directed and limited to whether or not the witness is telling the truth. 3A J. Wigmore, supra at §§ 920-23; C. McCormick, supra at §§ 41-42. In the case at bar, moral character evidence of former drug usage has no relevance upon the question of the witness’ credibility, and thus has no function in proper character impeachment.
¶24I must conclude, therefore, that evidence of former drug usage with the accompanying correlative social opprobrium it evinces has no proven relationship to a witness’ capacity or moral inclination for truthtelling. Unscientifically established admissions of this nature place before the jury evidence of unrelated misconduct which will inevitably tend *749to prejudice the defendant in the eyes of jurors. I would exclude all such evidence for the purposes of character impeachment, unless: (1) expert testimony establishes a probable effect upon a witness’ capacity for truthtelling, accord, Fields v. State, 487 P.2d 831 (Alas. 1971); People v. Ortega, 2 Cal. App. 3d 884, 83 Cal. Rptr. 260 (1969), or; (2) some relevance is established involving the witness’ credibility in the matter being litigated.
¶25The Crime Of Aiding And Abetting
¶26Copetitioner Milton LaVanway assigns error to jury instruction No. 10 delineating the elements of the offense, or charge of aiding and abetting.
¶27I would remand this case for a new trial consistent with the views expressed in this dissent.
¶28Rosellini and Utter, JJ., concur with Finley, J.
¶29It is of the utmost importance that it be understood that this case involves the admissibility of character impeachment testimony relating to former drug addiction; moreover, the state makes no contention that the admission of former drug usage extracted from the defendants was offered to prove motive. The question of motive is a separate and independent ground of evidence admissibility, and, therefore, is analytically unrelated to character impeachment. See generally 1-2 J. Wigmore, Evidence §§ 117-19, 385-87, 391-92 (3d ed. 1940). It seems to be common knowledge that narcotic addiction may lead an addict to resort to criminal activities to support the habit. Clearly motive evidence introduced to establish a causal link between a drug habit and a consequential robbery is properly admissible. In the instant case, however, there was no contention that the defendants’ use of narcotic drugs motivated the robbery. If the dissenting views expressed herein were to prevail, upon retrial, the state may establish a drug-related motive for the robbery. The record in this case, as presently posited, reveals no suggestion that the defendants acted out of a narcotic compulsion to feed their habit. Therefore, admissibility of such evidence upon the independent ground of criminal motive is not properly before this court.
¶30 Actually, a more descriptive term for an evidentiary assault upon a witness’ character might be more accurately and descriptively termed “credibility impeachment.”
¶31While it is true in the instant case that Virginia LaVanway offered some biographical data, however in the case of codefendant Milton LaVanway, the majority would appear to deem essential identification information, such as name, address, and profession coupled with defendant’s version of his activities on the day of the crime, to constitute an offer of good character. The lack of merit in this position is self-evident and requires no refutation. See generally 3A J. Wigmore, Evidence ch. 32 (J. Chadbourn rev. 1970). As an additional note, obviously, any such rule would “chill” the defendant’s constitutional right to take the witness stand in his own behalf. See Const. art. 1, § 22; RCW 10.52.040; State v. Hill, 83 Wn.2d 558, 520 P.2d 618 (1974). Cf. 8 J. Wigmore, Evidence § 2276 (McNaughton rev. 1971). For purposes of this dissent, I will assume, notwithstanding the facts, that the defendants have truly put their character into question.
¶32This is substantially the approach suggested in C. McCormick, The Law of Evidence § 45, at 95 (2d ed. E. Cleary 1972). “[A]s to drug *748addiction to which more social odium has been attached, many decisions allow it to be shown to impeach, even without evidence that it did in the particular case affect truth-telling, although apparently more courts, absent a particular showing of effect on the witness’s veracity, would exclude it. In respect to both addictions [to drugs and alcohol] the excluding courts seem to have the better of the arguments. It can scarcely be contended that there is enough scientific agreement to warrant judicial notice that addiction in and of itself usually affects credibility. Certainly it is pregnant with prejudice. On the other hand, there is an increasing recognition among non-legal authorities that addiction may in yarious instances be linked with personality and other defects which do bear upon credibility.” (Footnotes omitted.)
¶33Jury instruction No. 10
“You are instructed that every person concerned in the commission of grand lareency, whether he directly or indirectly commits the acts constituting the offense or aids or abets in the commission, is guilty of grand larceny.
“Thus, the act of one individual among several who are present at the scene and participate in grand larceny, would be the acts of each and all, as a principal, whether each of them took, stole, or carried away the property or not. For a person to be an aider or abettor by his presence, he must be ready to assist, ready to render assistance should it become necessary, or must assist the perpetrator of the crime by his presence.
“You are further instructed that to aid and abet may consist of words spoken, or acts done, for the purpose of assisting in the commission of a crime or of counseling, encouraging, commanding or inducing its commission. To constitute an aider or abettor, it is essential that the aider or abettor should share the criminal intent of the person or party who committed the offense.”
¶34Defendant’s proposed jury instruction No. 2. “It is provided by statute that every person concerned in the commission of a felony, gross misdemeanor or misdemeanor, whether he directly commits the act *750constituting the offense, or aids or abets in the commission, and whether present or absent; and every person who directly or indirectly counsels, encourages, hires, commands, induces or otherwise procures another to commit a felony, gross misdemeanor or misdemeanor, is a principal. There must be some overt act, the doing or saying of something, directly or indirectly contributing to a criminal act, and mere assent to a criminal act is insufficient.”