concurring and dissenting.
The unusual circumstances of this case, in which the victim of a cocaine overdose may have misled the police into thinking that he *121did not need medical care, warrant the remand ordered by the Court. Those same circumstances may have led the Court to apply principles of comparative fault rather than causation to guide the remand. Defining the relevant principles is not easy. One of the hardest tasks in law is to weave the various threads of doctrine that assemble the warp of the fabric of our tort law. All agree that once law enforcement officials arrest someone they have a duty to provide necessary medical care to the person in their custody. Revere v. Massachusetts Gen. Hosp., 463 U.S. 239, 103 S.Ct. 2979, 77 L.Ed.2d 605 (1983). Our instinct tells us that a criminal who overdoses on narcotics should not recover money damages from an arresting police officer. Our sense of principle tells us that the antecedent conduct of a prisoner does not relieve the custodians, be they jailers or police, of the duty to provide needed medical care to prisoners unable to care for themselves. Consider the case of a collision between two cars, one occupied by a fleeing felon and the other by a commuter returning home. Police arriving at the scene do not know which of the two unconscious bodies at the scene is that of the felon or that of the commuter. They take custody of both persons. Is their duty to provide emergency care to the felon eliminated by his antecedent misconduct? I think not.
Other examples may help to place the issues in context. If an epileptic who had drunk to excess were arrested at a protest rally for reasons unrelated to the drinking and had been placed handcuffed in the back seat of a police car, would the police be excused, under the “gatekeeping” principles of contributory negligence, from their duty to provide care if the substance abusing person suffered an epileptic seizure and died from a lack of needed care? Again, I would think not and would expect that our Court would so hold. That person, like Kiken, engaged in self-damaging conduct that made him vulnerable to injury if denied care while in police custody. What distinguishes the two eases? Is it that Kiken’s conduct was criminal? Consider the case of an accomplice to a drug deal who suffers from diabetes. The accomplice is arrested and placed in the back seat of a police cruiser. If the accomplice *122goes into a diabetic coma, are the police relieved of a duty to provide care because the antecedent crime has caused the accomplice to be vulnerable to such an injury? Again, I believe that the Court’s answer would be “no.” Because substance abuse or criminal conduct in themselves do not relieve police officers of their obligation to provide necessary medical care (after all, everyone in a police lockup has done something wrong), we must find a principle other than contributory negligence based on the substance abuse or criminal conduct that bars recovery. Although the facts of this case are basically simple, the principles to be applied are not. Several strands of familiar legal doctrine are interwoven in the resolution of this matter. The doctrines of avoidable consequences, aggravation of preexisting condition, contributory negligence, and causation each play a part.
In a fault-based system of tort reparation, the doctrine of contributory negligence serves to bar any recovery to a plaintiff whose fault contributed to the accident. Whatever its conceptual underpinnings, its effect is to serve as a gatekeeper, preventing certain parties from recovery for their injuries.1 Richard A. Epstein, The Social Consequences of Common Law Rules, 95 Harv. L.Rev. 1717, 1736-37 (1982). Under the common-law system of contributory negligence, any fault kept a claimant from recovering. Fault in that context meant a breach of duty that was comparable to the duty of the other actors to exercise such care in the circumstances as was necessary to avoid the risk of injury incurred. The prototype of such fault was the carriage driver who crossed the train tracks as the train was approaching the crossing. British Columbia Elec. Ry. Co. v. Loach, 1 App. Cas. 719 (P.C. *1231915). The application of the doctrine of contributory negligence was harsh, but clear. Comparative negligence is a legislative amelioration of the common law doctrine of contributory negligence. N.J.S.A 2A:15-5.1 to -5.3. An actor who is not more at fault than another may recover a reduced share of damages. The doctrine of comparative negligence is well intended but blurs the conceptual clarity of contributory negligence. In order to see the issue starkly, we must be able to see how the gatekeeping function of contributory negligence would work. Would the law intend that the antecedent misconduct of prisoners excuse jailers and police of a duty to provide care for prisoners in their custody? That, after all, is how the doctrine of contributory negligence would work.
Related in effect, but not in theory, to the doctrine of contributory negligence is the doctrine of avoidable consequences. That doctrine has its roots in the law of damages. It has application in the law of contract as well as in the law of torts. New Jersey Indus. Properties, Inc. v. Y.C. & V.L., Inc., 100 N.J. 432, 461, 495 A.2d 1320 (1985) (Stein, J., dissenting) (quoting 5A Corbin, Contracts § 1039 at 241 (1964)). The doctrine proceeds on the theory that a plaintiff who has suffered an injury as the proximate result of the tort of another cannot recover for any portion of the harm that by the exercise of ordinary care he or she could have avoided. See W. Page Keeton, et al., Prosser and Keeton on the Laiv of Torts § 65 at 458-59 (5th ed.1984). This doctrine has a simple thesis in public policy:
[I]t is not true that the injured person has a duty to act, nor that the conduct of the tortfeasor ceases to be a legal cause of the ultimate harm; but recovery for the harm is denied because it is in part the result of the injured person’s lack of care, and public policy requires that persons should be discouraged from wasting their resources, both physical or economic.
[Restatement (Second) of Torts § 918 at 500, cmt. a (1979).]
The doctrine of avoidable consequences normally comes into action when the injured party’s carelessness occurs after the defendant’s legal wrong has been committed. Contributory negligence, however, comes into action when the injured party’s carelessness occurs before defendant’s wrong has been committed or concurrently with it.
*124Finally, there is that simplest yet often most elusive aspect of tort law, that of causation. “ ‘[C]ausation’ is an inscrutably vague notion, susceptible to endless philosophical argument, as well as practical manipulation.” Glen O. Robinson, Multiple Causation in Tort Law: Reflections on the DES Cases, 68 Va. L.Rev. 713, 713 (1982). To recover in tort, “plaintiff must prove that defendant’s conduct constituted a cause in fact of his injuries and loss. An act or omission is not regarded as a cause of an event if the event would have occurred without it.” Skripek v. Bergamo, 200 N.J.Super. 620, 634, 491 A.2d 1336 (App.Div.), certif. denied, 102 N.J. 303, 508 A.2d 189 (1985).
These simple principles, well adapted to the case of the truck crossing the railroad track, are not so easily applied to more complex social circumstances. For example, in some cases carelessness that aggravates an injury (although not causing the injury), may precede the injury itself. See, e.g., Waterson v. General Motors Corp., 111 N.J. 238, 544 A.2d 357 (1988) (failure to use seatbelt, although not cause of injury, is cause of avoidable consequences). Because we did not wish to dilute entirely (by one driver’s failure to use a seatbelt) the responsibility of other motorists to drive carefully, we permitted the defense of contributory negligence for failure to use a seatbelt but limited the defense to that portion of the damages that could have been avoided by use of the seatbelt. Id. at 241, 544 A.2d 357. Thus, like many other principles of the common law, the doctrine had to be adapted to new, more complex circumstances.2
When the wrongdoer comes into police custody, the actor’s initial wrong is usually unrelated to the “exercise [of] such care in the circumstances as [is] necessary to avoid the risk of the injury incurred” that is the hallmark of contributory negligence. Ostrowski v. Azzara, 111 N.J. 429, 437, 545 A.2d 148 (1988). A *125criminal act or an act of substance abuse is an altogether different type of wrong than to drive a wagon carelessly over train tracks. Consider again the case of the overindulgent civil rights protestor. But for the misconduct of fellow protestors that caused the protest to get out of control, the mild overindulgence of the epileptic protestor created no risk of being deprived of medical care. The protestor breached no duty imposed by the common law to care for one’s own health. The same is true with respect to the diabetic who was an accomplice to the drug deal. Such misconduct does not constitute a breach of a duty in tort to care for one’s self — unless we conclude that one has a common-law duty not to commit a crime because one must anticipate that the police would not provide medical care. Stated differently, an individual’s duty to abide by our criminal laws is imposed to protect society at large, not to safeguard the health of the actor. Thus, the majority’s application of principles of contributory negligence to this ease does not accord with our precedent.
On the other hand, the police cannot be held responsible if their conduct was not the cause of injury. Moreover, every person has a duty to mitigate damages. Thus, I agree with the majority that the fact that “an arrestee has the capacity to engage in self protective measures,” ante at 116, 685 A.2d at 1280, is relevant to the imposition of liability. Presumably the Court is referring to Kiken’s failure to request medical help. However, the analysis should be that of causation or damages rather than breach of duty. As this case suggests, the officers may have had no way of knowing that the person in custody needed care.
In Lee v. Kiku Restaurant, 127 N.J. 170, 603 A.2d 503 (1992), the Court held that the contributory negligence of a person who drinks to excess should be considered in comparison to that of the tavern that serves the visibly intoxicated patron. There, the tavern served both the plaintiff and his driver after they had become visibly intoxicated. In assessing the tavern’s liability for injuries sustained by the passenger in a subsequent car accident, the Court concluded that the jury should have considered the *126passenger’s fault in drinking to the point of intoxication. Id. at 183, 603 A.2d 503. Although the plaintiff in Lee was a passenger in the car, the principles of that case apply to suits brought by injured drivers as well. Id. at 182, 603 A.2d 503; Fisch v. Bellshot, 135 N.J. 374, 388-89, 640 A.2d 801 (1994). The reason that the principles' of Fisch and Lee are not applicable to the circumstances of this case is that the self-damaging conduct of drunken drivers directly causes their injuries. The substance abuser drives the car into the tree. In contrast, the arrested person does not drive into the tree of medical neglect. Rather, his freedom of movement has been curtailed a~nd he is unable to care for himself. In Vallejo v. Rahway Police Department, 292 N.J.Super. 333, 678 A.2d 1135 (App.Div.), certif. denied, 147 N.J. 262, 686 A.2d 763 (1996), the Appellate Division reviewed the analogous principles that apply when an intoxicated prisoner attempts suicide. The court did not suggest that the previous criminal act of domestic violence that occasioned the prisoner’s arrest should form the basis of a defense of contributory negligence.
Hence, we should hold that if a person in police custody, able to appreciate the circumstances in which he is found, informs the police he does not need medical care, that person cannot later recover for injuries because there is no causal connection between the conduct of the police and the plaintiffs injuries. Because plaintiff misled the police, the chain of causation is broken and the jury should be instructed that plaintiff cannot recover in tort. If, however, the plaintiff is unable to appreciate the risks of his behavior, the jury should be instructed to apportion damages based on the extent to which plaintiffs voluntary ingestion of drugs or alcohol (like the person who does not wear a seatbelt) caused harm to plaintiff. Public policy requires that every person bear that responsibility.
Thus, I agree that a new trial is required in the circumstances of this case. Because of the strong public policy against the illegal consumption of narcotics, the majority states the result in terms of *127duty rather than causation or avoidance of harm. As the Court has “drawn the line in [such] cases involving voluntary consumption of alcohol or drugs,” ante at 120, 685 A.2d at 1282, the results will not greatly differ. The Court focuses on the ability of the person in custody to appreciate the risks of harm. “Under the circumstances of this case, it is neither unreasonable nor unfair to impose a duty of self-care on [the prisoner] requiring him not to use cocaine and if used, to inform the police that he was ill from ingesting cocaine.” Ante at 116, 685 A.2d at 1280.
Both the majority and dissent agree on the core values involved:
[I]f the police knew or should have known that [the prisoner] had overdosed or was otherwise in need of emergent medical assistance, regardless of what necessitated that need, the police had a legal duty to seek medical assistance immediately. Our law does not permit law enforcement agents to ignore the medical needs of a person taken into custody simply because the medical emergency was created by the volitional act of ingesting illegal drags or alcohol. The fact that [the prisoner] acted in an unacceptable manner in taking drugs ... does not diminish the police’s responsibility of providing medical assistance in a timely fashion to an arrestee. It would be both morally and legally indefensible for the police intentionally to ignore [a prisoner’s] need for emergent medical assistance.
[Ante at 117, 685 A.2d at 1281.]
Those basic principles will guide the retrial of this case.
STEIN, J., joins in this opinion.
O’HERN and STEIN, JJ., concur in part; dissent in part.
For affirmance — Justices HANDLER, POLLOCK, GARIBALDI and COLEMAN — 4.
Legal historians still ponder the origins of such doctrines, debating whether the concepts of negligence and contributory negligence were meant to further the interests of an expanding industrial society or simply reflected the highly individualistic attitudes of the common law. Jordan H. Leibman, Comparative Contribution and Intentional Torts: A Remaining Roadblock to Damages Apportionment, 30 Am. Bus. LJ. 677, 707 n. 2 (1993); Robert J. Kaczorowski, The Common-Law Background of Nineteenth-Century Tort Law, 51 Ohio St. L.J. 1127, 1127-28 (1990).
We similarly modified the usual doctrine of aggravation. Fosgate v. Corona, 66 N.J. 268, 330 A.2d 355 (1974) (holding that physician who asserts defense of aggravation of preexisting condition bears burden of demonstrating proper segregation of damages).