I dissent.
The trial court erred in excluding the seat belt evidence. That evidence was offered to show plaintiff’s injuries in part were caused by her failure to use the safety device provided by the manufacturer. In accordance with the equitable principles recently announced in Li v. Yellow Cab Co. (1975) 13 Cal.3d 804 [119 Cal.Rptr. 858, 532 P.2d 1226], the evidence is admissible because it is relevant to the issue of damage.
The By The Court opinion concludes the evidence is inadmissible because contributoiy negligence is not a defense. True, Li holds contributory negligence no longer exists in California in negligence cases. However, Li also holds that an injured plaintiff’s recoveiy shall be reduced in proportion to his fault. The majority offers no reason for its failure to apply the Li principle in this product liability case. The issue was unquestionably raised by the defendant’s offer of proof. Why should Li not apply across the board?
Prior to the Li decision, a plaintiff’s contributory negligence barred all recoveiy for loss incurred by reason of a defendant’s negligence except where defendant had the last clear chance, in which case plaintiff could recover all loss. Repudiating the “ ‘all-or-nothing’ ” rule of contributory negligence, this court reasoned: “the doctrine is inequitable in its operation because it fails to distribute responsibility in proportion to fault.3 . . . The basic objection to the doctrine—grounded in the primal concept that in a system in which liability is based on fault, the extent of fault should govern the extent of liability—remains irresistible to reason and all intelligent notions of fairness.” (13 Cal.3d 804, 810-811.)
*373Finding no justification for continuing the rule of contributory negligence, concluding the rule was not truly statutory,1 and rejecting the practical difficulties in applying comparative fault, this court determined “that the time for a revision of the means for dealing with contributory fault in this state is long past due and that it lies within the province of this court to initiate the needed change....” (13 Cal.3d 804, 826.) Thus, “ ‘pure’ ” comparative negligence was adopted—distributing “liability in direct proportion to fault in all cases.” The last clear chance doctrine and assumption of risk defense—to the extent it is a variant of contributory negligence—were abolished. (13 Cal.3d at pp. 827-829.)
The equitable principles of comparative fault must now be applied in strict liability cases. (Dippel v. Sciano (1967) 37 Wis.2d 443 [155 N.W.2d 55, 64-65]; Edwards v. Sears, Roebuck and Company (5th Cir. 1975 [Miss.]) 512 F.2d 276, 290; Hagenbach v. Snap-on Tools Corp. (1972 [N.H.]) 339 F.Supp. 676, 680-683.)2
The strict liability doctrine was established .in Greenman v. Yuba Power Products, Inc. (1963) 59 Cal.2d 57, 62 [27 Cal.Rptr. 697, 377 P.2d 897, 13 A.L.R3d 1049]: “A manufacturer is strictly liable in tort when an article he places on the market, knowing that it is to be used without inspection for defects, proves to have a defect that causes injury to a human being.”
Strict or product liability is a fault doctrine—not an absolute or no-fault doctrine. (Lascher, Strict Liability in Tort for Defective Products: The Road to and Past Vandermark (1965) 38 So.Cal.L.Rev. 30, 37.) While the injured plaintiff is not required to prove the manufacturer is negligent, he must prove the manufacturer is at fault. (Comment, Tort Defenses to Strict Products Liability (1969) 20 Syracuse L.Rev. 924, 925-928.) Thus, the plaintiff must show that the product was in some way *374defective (Price v. Shell Oil Co. (1970) 2 Cal.3d 245, 251 [85 Cal.Rptr. 178, 466 P.2d 722]); he must show that the manufacturer produced a product in a condition justifying liability for the ensuing injury. The mere introduction of a product into the stream of commerce is not enough to impose liability for subsequent damage. The manufacturer is not an insurer. (Cronin v. J.B.E. Olson Corp. (1972) 8 Cal.3d 121, 133 [104 Cal.Rptr. 433, 501 P.2d 1153].) Thus, the auto manufacturer is not liable for every occurrence involving its cars, but only for the relatively few accidents attributable to defects.
This court’s pioneering effort in product liability was never intended to abolish considerations of fault; rather, it “was to relieve the plaintiff from problems of proof inherent in pursuing negligence [citation] and warranty [citation] . . . .” (Cronin v. J.B.E. Olson Corp., supra, 8 Cal.3d 121, 133.)
While “defect” has not been defined precisely by our courts, each attempt to do so reflects the fault concept. The Restatement Second of Torts describes a defective condition as one “unreasonably dangerous to the user or consumer or to his property.” (§ 402 A.) Rejecting the Restatement test, this court recently described the unreasonably dangerous requirement as “an element which rings of negligence.” (Cronin v. J.B.E. Olson Corp., supra, 8 Cal.3d 121, 132.) While recognizing that there was then no all encompassing definition, the court stated that a defective product is one failing to equal the quality of most like products, the deviation from the norm causing injury. A similar approach is reflected by Prosser, Torts (4th ed. 1971) pages 659-660: “The prevailing interpretation of ‘defective’ is that the product does not meet the reasonable expectations of the ordinary consumer as to its safety. It has been said that this amounts to saying that if the seller knew of the condition he would be negligent in marketing the product.”
Resort to the warranty concept—the historical basis for product liability—again shows the doctrine to be founded in fault. Breach of express representation or failure to comply with legally imposed obligations of merchantability or fitness obviously reflect fault. Similar considerations led the Wisconsin Supreme Court to conclude, in holding comparative fault principles applicable to strict liability cases, that strict liability is equivalent to negligence per se. (Dippel v. Sciano, supra, 155 N.W.2d 55, 65.)3
*375Like the contributory negligence doctrine repudiated in Li, existing law governing plaintiff negligence in strict liability cases is an “all- or-nothing” rule. The plaintiff’s ordinary negligence does not bar his recovery, but his voluntary and unreasonable encountering of known danger does. (Henderson v. Harnischfeger Corp. (1974) 12 Cal.3d 663, 672 [117 Cal.Rptr. 1, 527 P.2d 353]; Luque v. McLean (1972) 8 Cal.3d 136, 145 [104 Cal.Rptr. 443, 501 P.2d 1163].) Dean Prosser’s “kernel” of comment, critical of the former contributory rule in negligence cases, is applicable to the existing rule in strict liability cases. “It places upon one party the entire burden of a loss for which two are, by hypothesis, responsible.” (Prosser on Torts, supra, § 67, p. 433.)
Other considerations leading to the rejection of contributory negligence and acceptance of comparative negligence in Li are applicable to strict liability cases.
The harshness of the contributory negligence rule was traditionally dramatized by pointing to the case where the plaintiff’s deviation from the community standard was slight and the defendant’s extreme. (See e.g., Prosser, Torts (4th ed. 1971) § 67, p. 433.) The harshness often led juries to compromise in contributoiy negligence cases. (Id.; Li v. Yellow Cab Co., supra, 13 Cal.3d at p. 811.) In Li the court pointed out the process is haphazard apd detracts from public confidence in the ability of the law and legal institutions to assign liability on a just and consistent basis. (13 Cal.3d at pp. 811-812.) When in a products liability case the plaintiff’s conduct is extreme and the defendant’s deviation from the community expectation slight, it is equally harsh to require the defendant to bear the entire loss, and we can expect that a failure to adopt equitable principles in the product liability case will produce a similar loss of public confidence in the law.4
*376Prior to Li, negligent plaintiffs ordinarily fared better seeking recovery in strict liability than in negligence, but this furnishes no basis for rejecting the equitable principle of comparative fault. The difference in treatment accorded negligent plaintiffs was due to the rule that ordinary negligence was not a defense in strict liability cases. Although some authorities have attempted to justify that rule by analogy to principles governing absolute liability for abnormally dangerous activity (e.g., Rest.2d Torts, § 402 A, com. n), strict liability is not absolute liability since the design, manufacture and distribution of chattels are not abnormally dangerous activities. The analogy therefore fails.
The best explanation, as Professor Schwartz appropriately notes, for disallowing contributory negligence to bar product liability “focuses on the modern distrust of the defense as a complete bar to an injured plaintiff’s claim.” (Schwartz, Comparative Negligence (1974) § 12.6, pp. 204-205; Noel, Defective Products: Abnormal Use, Contributory Negligence, and Assumption of Risk (1972) 25 Vand.L.Rev. 93, 117-119.) Dislike of the “all-or-nothing” rule must lead not to a substitute “all-or-nothing” rule, but rather, as Li teaches, to the equitable principle of comparative fault.
Therefore, strict liability for a defective product being a fault doctrine, the “irresistible” reasoning of Li must again control. As in Li, the “all-or-nothing” concept fails justice because “in a system in which liability is based on fault, the extent of fault should govern the extent of liability.” (13 Cal.3d at p. 811.)
In addition, comparative, fault principles allow balancing manufacturer-seller responsibility with plaintiff misconduct, commensurate with the dual policy underlying product liability: (1) protecting those who are powerless to protect themselves from harm caused by a defective product (Price v. Shell Oil Co., supra, 2 Cal.3d 245, 251; Greenman v. Yuba Power Products, Inc., supra, 59 Cal.2d 57, 63); and (2) spreading loss among those best able to bear it (Luque v. McLean, supra, 8 Cal.3d 136, 145; Escola v. Coca Cola Bottling Co. (1944) 24 Cal.2d 453, 462 [150 P.2d 436] (Traynor, J., concurring)).
Protection is not impaired by weighing plaintiff’s fault in determining the amount of recovery. The plaintiff is at fault only if he fails to act as a reasonable person in similar circumstances, thereby aggravating the harm to himself. If so, his recovery should be diminished proportionate*377ly. On the other hand, if powerless to protect himself, he simply is not at fault and his damage is undiminished.
The concept of comparative fault is also consistent with the second policy—loss allocation. While it is equitable that society at large— through the manufacturer—bear the cost of compensating injury due to a defective product, society should not be forced to bear that part of the loss attributable to the injured’s own misconduct. (Schwartz, Comparative Negligence, supra, pp. 204, 206-207; see Levine, Buyer’s Conduct as Affecting the Extent of Manufacturer’s Liability in Warranty (1968) 52 Minn. L. Rev. 627, 652-663; Epstein, Products Liability: Defenses Based on Plaintiff’s Conduct (1968) Utah L.Rev. 267, 284.)
Application of comparative fault principles to the strict liability case provides uniformity in the law, simplifying trials. A plaintiff claiming injury from a product may seek recovery either in strict liability or in negligence (Pike v. Frank G. Hough Co. (1970) 2 Cal.3d 465, 470-475 [85 Cal.Rptr. 629, 467 P.2d 229]), and this court has recognized that such plaintiff may benefit by resort to negligence principles in a product liability case (Jiminez v. Sears, Roebuck & Co. (1971) 4 Cal.3d 379, 384 [93. Cal.Rptr. 769, 482 P.2d 681]). While comparative fault rules are still in infancy, it is already apparent grave confusion exists if comparative principles are applied exclusively to negligence actions. Again, in the negligence cause, plaintiff’s own negligence reduces but does not bar his recovery. (Li v. Yellow Cab Co., supra, 13 Cal.3d 804, 824-825.) In the strict liability cause, plaintiff’s own negligence is now either disregarded or it bars the cause entirely, depending on whether he voluntarily and unreasonably encountered a known danger. (Luque v. McLean, supra, 8 Cal.3d 136, 145.) Unequal treatment of plaintiff negligence must lead to court and jury confusion. We may anticipate that, in the event comparative principles are not extended to include strict liability actions, confusion will compound in this expanding field.
Apportioning fault in a strict liability case will present a jury problem. But again, Li held that the difficulties inherent in assigning percentages of fault are not insurmountable. (13 Cal.3d at pp. 823-824.) It has been pointed out that apportionment in the strict liability case is no different from apportionment in the negligence per se case. In the latter, the law also fixes the standard of conduct, and comparative negligence jurisdictions have been assigning percentages in negligence per se cases for years. (Dippel v. Sciano, supra, 155 N.W.2d 55, 64-65.)
*378Plaintiff’s own fault being a proper issue in the case, the trial court erred in excluding the seat belt evidence. (See Truman v. Vargas (1969) 275 Cal.App.2d 976, 982 [80 Cal.Rptr. 373].)5
*379The judgment should be reversed and the cause remanded for retrial on the issue of damage.
McComb, J., concurred.
Appellants’ petition for a rehearing was denied August 4, 1976.
“ Dean Prosser states the kernel of critical comment in these terms: ‘It [the rule] places upon one party the entire burden of a loss for which two are, by hypothesis, responsible.’ (Prosser, Torts (4th ed. 1971) § 67, p. 433.) Harper and James express the same basic idea: ‘[TJhere is no justification—in either policy or doctrine—for the rule of contributoiy negligence, except for the feeling that if one man is to be held liable *373because of his fault, then the fault of hh¡n who seeks to enforce that liability should also be considered. But this notion does not require the all-or-nothing rule, which would exonerate a very negligent defendant for even the slight fault of his victim. The logical corollary of the fault principle would be a rule of comparative or proportional negligence, not the present rule.’ (2 Harper & James, The Law of Torts (1956) § 22.3, p. 1207.)”
The dissent in Li disputed only the conclusion that the contributory negligence rule was not a statutory one.
The Supreme Court of Oklahoma stated comparative principles were inapplicable to strict liability cases because the statute providing for comparative fault was expressly limited to negligence cases. (Kirkland v. General Motors Corporation (1974) 521 P.2d 1353, 1367.)
The court reasoned that a defective product, like a violation of a safety statute, can create an unreasonable risk of harm, and the minimum standard of care, production of *375nondefective products, like compliance with the safety statute, is established by law. (155 N.W.2d at pp. 64-65.)
One method of limiting the loss of confidence due to the refusal to apply equitable principles is to expand the assumption of risk and misuse defenses thereby barring all recovery. An illustration of such expansion appears in the only case refusing to apply comparative principles in a strict liability case. Confronted by a plaintiff guilty of drunk driving and a statute not permitting resort to comparative principles, the court concluded that drunk driving constituted a misuse of the vehicle. (Kirkland v. General Motors Corporation, supra, 521 P.2d 1353, 1367.) (The court did not discuss whether drunk driving was a foreseeable use of the vehicle. (Cf. Majority opn., pp. 370-371.)) Denial of all recovery when both parties are at fault, however, is contrary to the equitable principles of Li.
Contrary to the claim in the By The Court opinion (fn. 2) the issue of comparative fault was presented to this court and is properly before us. Counsel filed briefs in this c.ase prior to Li and, of course, did not mention that case. Counsel also did not undertake the heroic task of urging that we repudiate the contributory negligence doctrine in negligence cases. It obviously would be unrealistic to expect him to have done so, this being a strict liability case. Nor did' counsel directly attack the general rule that contributory negligence is not a defense in strict liability cases. Rather, counsel throughout has urged that special rules should apply where, as here, the defect in the automobile does not cause the accident but merely aggravates the injury. One of the special rules urged for the aggravation case is that plaintiff’s failure to take reasonable precautions against aggravated injuries (wear a seat belt) should reduce damages, thus raising the comparative principle.
Adopting comparative negligence, Li holds that, rather than barring all recovery, plaintiff fault will serve to reduce damage in a negligence case. The objections and contentions made—not the authority cited—should determine what issues are properly before this court. This being strict liability, not negligence, a party attempting to raise the Li principle would be technically and practically incorrect in urging comparative negligence. Instead, the contention would have to be phrased in different terminology, and the use of the term “reduction of damages”—the ultimate effect of application of the Li principle—is appropriate. Thus, the comparative principle has been urged throughout the trial and appeal.
Failure to cite Li or other comparative negligence authority is not determinative when counsel has urged adoption of the correct theory or rule of law. The objections and contentions made—not authorities cited—must determine what issues are properly before this court. To hold that failure to cite our favorite authorities or to use special jargon precludes consideration of a contention made constitutes judicial arrogance. In sum, defendants, by urging throughout these proceedings that the seat belt evidence is admissible to reduce damages, have properly raised the comparative issue.
If there be any doubt as to the presence of the comparative fault issue in this case, it was eliminated when the Court of Appeal reversed the trial court’s decision on the ground that the jury should have been permitted to determine “as a question of fact that the use of the seat belts would have reduced plaintiff’s damages.” (Horn v. General Motors Corp. (Cal.App.) 110 Cal.Rptr. 410, 416.)
The By The Court opinion also seeks to avoid the comparative principle on the ground that the judgment was entered prior to the Li decision and Li held comparative negligence is applicable only to cases where trial commenced subsequent to that decision. (Li v. Yellow Cab Co., supra, 13 Cal.3d 804, 829.) The issue in the instant case is not whether to apply “comparative negligence”; again, this is a strict liability case. The issue here is whether comparative fault should be applied in strict liability cases.
The very reasons relied upon in Li for adopting limited retroactivity require that defendants here be permitted the benefit of the comparative fault principle. Li pointed out that a determination that retroactivity be limited turns upon “considerations of fairness and public policy.” It was concluded: “Upon mature reflection, in view of the very substantial number of cases involving the matter here at issue which are now pending in the trial and appellate courts of this state, and with particular attention to considerations of reliance applicable to individual cases according to the stage of litigation which they have reached, we have concluded that a rule of limited retroactivity should obtain here.” (13 Cal.3d at p. 829.) By adopting the cutoff date based on relationship of the Li decision to the trial date, it is apparent that Li sought to protect the *379interests of litigants who had tried their cases under the old law and to mitigate the great burden upon our trial and appellate courts resulting if Li were applied to all pending cases.
Application of the Li cutoff date will defeat both purposes. Strict liability being a major source of litigation, numerous cases subsequent to Li involving the applicability of comparative fault are in existence. Whether or not this court ultimately concludes that comparative fault is applicable to strict liability, we will be required, by applying the Li cutoff date, to reverse the decisions of those judges who subsequent to Li anticipated a contrary result. Considerations of fairness and public policy reflected by Li require this court to determine the issue as expeditiously as feasible, and to apply as a cutoff date, not the Li date, but the date of the new decision.