Opinion of the Court. 330 U.S. So far as the Unions, both local and national, are concerned, the necessity under our construction for an instruction based on § 6 is apparent. The United Brotherhood was not a party to any of the agreements. Local unions took a more definitive part than the United Brotherhood. In some instances the name of a local union was signed to the agreement that contained the restrictive clause. Necessarily acts performed by or for the unions were done by their individual officers, members or agents. We do not enter into an analysis of the evidence that was relied upon to show the participation of the unions in the conspiracy. The evidence in any new trial may be quite different. No matter how strong the evidence may be of an association's or organization's participation through its agents in the conspiracy, there must be a charge to the jury setting out correctly the limited liability under § 6 of such association or organization for acts of its agents.20 For a judge may not direct a verdict of guilty no matter how conclusive the evidence." There is no way of knowing here whether the jury's verdict was based on facts within the condemned instructions, note 19 above, or on actual authorization or which are defendants in this case in the same manner as you determine that of the corporations, that is, by an examination of the acts of their agents. "In this case, several individuals are named as defendants, together with a number of corporations. While these defendants have been jointly indicted and charged with the offenses contained in the indictment, each defendant is entitled to an independent consideration by you of the evidence as it relates to his conscious participation in the alleged unlawful acts, and it is your duty to determine the guilt or innocence of each individual separately." 20 See Battle v. United States, 209 U. S. 36, 38. 21 Sparf and Hansen v. United States, 156 U. S. 51, 105, dissent 173. Compare Capital Traction Company v. Hof, 174 U. S. 1, 13. 395 Opinion of the Court. ratification of such acts, note 18.2 A failure to charge correctly is not harmless, since the verdict might have resulted from the incorrect instruction. We are of the opinion, therefore, that the judge should have instructed the jury as to the limitations upon the association's liability for the acts of its agents under § 6. The error is aggravated by the failure to give the correct charge upon request. The suggestion is made that the alert and powerful unions and corporations gain the greatest degree of immunity under our interpretation of § 6. That is not the case. Section 6 draws no distinction as to liability for unauthorized acts between the large and the small, between national unions and local unions, between powerful unions and weak unions, between associations or organizations and their members. And we draw no such distinctions. There is no implication in what we have said that an association or organization in circumstances covered by § 6 must give explicit authority to its officers or agents to violate in a labor controversy the Sherman Act or any other law or to give antecedent approval to any act that its officers may do. Certainly an association or organization cannot escape responsibility by standing orders disavowing authority on the part of its officers to make any agreements in violation of the Sherman Act and disclaiming union responsibility for such agreements. Facile arrangements do not create immunity from the act, whether they are made by employee or by employer groups. The condi 22 Bird v. United States, 180 U. S. 356, 361: "The chief object contemplated in the charge of the judge is to explain the law of the case, to point out the essentials to be proved on the one side and the other, and to bring into view the relations of the particular evidence adduced to the particular issues involved." See Pierce v. United States, 314 U.S. 306. Opinion of the Court. 330 U.S. tions of liability under § 6 are the same in the case of each. The grant of authority to an officer of a union to negotiate agreements with employers regarding hours, wages, and working conditions may well be sufficient to make the union liable. An illustrative but nonrestrictive example might be where there was knowing participation by the union in the operation of the illegal agreement after its execution. And the custom or traditional practice of a particular union can also be a source of actual authorization of an officer to act for and bind the union. Our only point is this: Congress in § 6 has specified the standards by which the liability of employee and employer groups is to be determined. No matter how clear the evidence, they are entitled to have the jury instructed in accordance with the standards which Congress has prescribed. To repeat, guilt is determined by the jury, not the court. The problem is not materially different from one where the evidence against an accused charged with a crime is well-nigh conclusive and the court fails to give the reasonable-doubt instruction. It could not be said that the failure was harmless error.23 It is suggested that since "conscious participation" was required for conviction by the instructions given, error as to the individual defendants cannot be found under any theory of the rule of § 6. But we think that failure to instruct the jury on the imputation of guilt from the acts of others as limited in labor disputes by § 6 affects the individuals as well as the associations. The section covers organizations and their members alike. Individuals, without association authority, may be guilty of such a conspiracy as this under the Sherman Act, but under § 6 they will not be guilty merely because they are members or officers of a guilty association. Nor are individuals guilty 23 Weiler v. United States, 323 U. S. 606; Bruno v. United States, 308 U. S. 287. 395 Opinion of the Court. because of acts of other individuals in which they did not participate, or which they did not authorize or ratify. Although an illegal conspiracy under the Sherman Act was proven at the trial, the individuals are entitled to have their participation weighed by a jury under an instruction explaining the circumstances under which § 6 permits acts of other individuals or of associations or of organizations in labor disputes to create personal liability. To instruct only that conscious participation of the individual is required leaves a jury free to weigh an individual's guilt in the light of unauthorized and unratified acts of others with whom he is associated but in whose acts he has not participated. As the evidence of any individual's activities in the alleged conspiracy is a minor part of the evidence as to the entire scheme, this delimitation of his responsibility is important. Certiorari was granted to two employer groups, Nos. 8 and 10, each containing an incorporated trade association and its officers and members, both individual and corporate. Both groups combatted the indictment by demurrer on the ground that, as the restrictive agreement was directed at the maintenance of proper working conditions, it did not state a crime under the Sherman Act. The demurrer was overruled by the trial court. Our decision in Allen Bradley Company requires us to uphold this conclusion. Thereafter pleas of nolo contendere were entered by each defendant in the employer petitioner groups. Each of the employer petitioners, if they had stood trial, as we have indicated hereinbefore, would have been entitled to the same instruction under § 6 as we have held the union group should have received. And though the failure so to charge was not excepted to, we would not be precluded from entertaining the objection." The errone 24 Wiborg v. United States, 163 U. S. 632, 658; Brasfield v. United States, 272 U. S. 448, 450; see also United States v. Atkinson, 297 U. S. 157, 160. And see Rules of the Supreme Court, Rule 27. Opinion of the Court. 330 U.S. ous charge was on a vital phase of the case and affected the substantial rights of the defendants. We have the power to notice a "plain error" though it is not assigned or specified.25 In view of their plea of nolo contendere, does justice require that these employer groups should now be given an opportunity to stand trial in the situation created by our subsequent rulings in the Allen Bradley case and in this case? We think that it does. 26 This present decision furnishes a guide for the application of § 6 to liability for acts of agents in labor disputes. Ordinarily a plea of nolo contendere leaves open for review only the sufficiency of an indictment. However, in view of the then existing uncertainty as to liability for contracts between groups of employers and groups of employees that restrained interstate commerce and the application of § 6 of the Norris-LaGuardia Act, we conclude that in this exceptional situation the employer groups, also, should have an opportunity to make defense to the indictment.27 The judgments in each case are reversed and the causes remanded to the District Court. MR. JUSTICE JACKSON took no part in the consideration or decision of this case. 25 Weems v. United States, 217 U. S. 349, 362; Mahler v. Eby, 264 U. S. 32, 45; Sibbach v. Wilson & Co., 312 U. S. 1, 16; see also Kessler v. Strecker, 307 U. S. 22, 34. And see Rules of Criminal Procedure, Rule 52 (b). 26 Nolo contendere "is an admission of guilt for the purposes of the case." Hudson v. United States, 272 U. S. 451, 455; United States v. Norris, 281 U. S. 619, 622. And like pleas of guilty may be reviewed to determine whether a crime is stated by the indictment. Hocking Valley R. Co. v. United States, 210 F. 735, 738; Tucker v. United States, 196 F. 260, 262. 27 See Husty v. United States, 282 U. S. 694, 703; Ashcraft v. Tennessee, 322 U. S. 143, 155-56; R. F. C. v. Prudence Group, 311 U. S. 579, 582; Watts, Watts & Co. v. Unione Austriaca, 248 U. S. 9, 21; Montgomery Ward & Co. v. Duncan, 311 U. S. 243, 254. |