Opinion by
Packel, J.,The progress of the law in extending liability without fault to product suppliers should not be in disregard of fundamentals pertaining to the tort law of causation. In negligence cases there has been the modern admixture of foreseeability and causation to determine the existence of liability.1 If in a negligence case foreseeability and cause are to be examined to determine the scope of liability, it would seem that the same should be true in a case of unintentional conduct involving liability without fault.2
The application of the concepts of foreseeability and legal cause to products liability makes it manifest there should be no arbitrary limitation of liability to only purchasers and their families. In this respect we are of the view that product liability may extend to persons not in privity or unconnected with the original transaction.
TMs case turns on the question of whether there should be liability for injury resulting from the playfulness of a dog when normally there is no such liability to a person injured thereby. Should there be liability on the part of one who, without fault, enables such a dog to wander? In the physical or philosophical sense the supplying of a defective ring that was supposed to hold the dog was a cause of the injury. That, *335however, is not a sufficient basis for liability.3 The determination should be whether that was only a “but for” cause and not a legal cause. The answer in this case should be no different from that in a negligence case. If the owner had left his dog with a friend while on vacation, would there be liability for a similar injury if the friend had carelessly permitted the dog to leave the premises?4
There appears to be no significant body of law involving causation as applied to product liability cases, but the situation is otherwise with respect to negligence cases. The Restatement 2d Torts, §430, states the necessity of an adequate causal relation as follows: “In order that a negligent actor shall be liable for another’s harm, it is necessary not only that the actor’s conduct be negligent toward the other, but also that the negligence of the actor be a legal cause of the other’s harm.” In more detailed analysis, Comment 5 of that section points out that the duty to protect some persons does not extend to other persons: “So too, if the actor is under a duty to take positive steps for the protection of particular classes of persons only, his failure to take such steps subjects him to liability only to such persons and cannot subject him to liability to third persons to *336whom he owes no such duty.” Learned Hand, J., in Sinram v. Pennsylvania R.R., 61 F. 2d 767, 770 (2d Cir. 1032), pointed out: “But so long as it is an element of imposed liability that the wrongdoer shall iu some degree disregard the sufferer’s interests, it can only be an anomaly, and indeed vindictive, to make him responsible to those whose interests he has not disregarded.”
If a vicious dog escaped and bit one or more persons, the existence of a duty to protect those persons would not mean that there was a duty to protect a person hurt by a non-vicious dog.5 Magruder, C. J., in Marshall v. Nugent, 222 F. 2d 604, 610 (1st Cir. 1955), pointed out: “Bach of the requirement that the defendant’s culpable act must have been a proximate cause of the plaintiff’s harm is no doubt the widespread conviction that it would be disproportionately burdensome to hold a culpable actor potentially liable for all the injurious consequences that may flow from his act, i.e., that would not have been inflicted ‘but for’ the occurrence of the act.”
Although §402A of Restatement 2d on Torts sets forth the modem rule of products liability, it has no provision dealing with the problem, of legal causation. That issue is referred to collaterally in Oomment a to §435B, which deals with unintended consequences of intentional invasions, as follows: “The rale stated in this Section affects only the measure of damages for a tort, but is based upon the principle which underlies both rules, namely, that responsibility for harmful consequences should be carried further in the case of one who does an intentionally wrongful act than in the *337case of one who is merely negligent or is not at fault.” Comment e of §430, which deals with the necessity of adequate causal relation provides: “Although the rule stated in this Section is stated in terms of the actor’s negligent conduct, the necessity that the conduct be a legal cause of the harm is equally applicable where the conduct is intended to bring about the harm, or where it is such as to result in strict liability. The applicable rules as to what constitutes legal cause are not, however, entirely the same as those for negligent conduct. See §870, and §519 and Comments.” Section 870 refers to liability for intended consequences and Section 519 refers to liability for ultra hazardous activities.
The restriction of liability to harm coming within the scope of the duty is illustrated by the two cases decided in this Court. In Chamberlain v. Riddle, 155 Pa. Superior Ct. 507, 510, 38 A. 2d 521, 523 (1944), the defendant in violation of the law permitted his automobile to be driven by an unlicensed driver and yet the Court held that the defendant was not liable for harm done by the unlicensed driver, as follows: “Even if we were to assume that in permitting Strasser to operate his car, appellee was guilty of a violation of the penal provision of the Code, there is nothing to show that the violation was the proximate cause of minor appellant’s injury.” Likewise in Barshay v. American Ice Co., 84 Pa. Superior Ct. 538, 540 (1925), Keller, J., held that the leaving of a horse unattended, though careless because of the danger of runaways, was not the legal cause of the horse biting a child: “Undoubtedly one who leaves a horse unhitched or unattended on a city street takes the risk of whatever the horse may do by reason of his being unhitched or unattended; and if a person is injured because of the owner’s failure to have his horse hitched or attended, a prima facie case of negligence is made out sufficient to take the case to the jury. But the principle has no *338application to an injury not caused by, nor haying any relation to, the owner’s failure to hitch or attend his horse. All the cases cited above were runaways where the failure to hitch or tie the horse was directly connected with the accident and resulting injury. . . . But this accident, — a sudden snap at the child, — could have occurred just as well whether the horse was hitched or not, and whether a driver was on the wagon or not, or even if both measures had been resorted to. It had no causal connection with the failure to hitch the horse or hold the reins while ice was being delivered. There being no other evidence of defendant’s negligence its point for binding instructions should have been affirmed.”
In the instant case, the failure of the ring to confine the dog was in conjunction with a breach of duty by the supplier to keep the dog confined, but that breach had no legal connection with harm brought about by the playfulness of the dog. In a practical sense, it can be said that a plaintiff who has no cause of action because of the playfulness of a dog, should not acquire a cause of action because of the violation of a duty, imposed without fault, which enabled the dog to wander. The public concern which brought about products liability without fault is well served by permitting recovery by anyone encompassed within the scope of the duty, without a broadening of the liability to allow recovery by one outside the scope of the duty.
The order of the court below is affirmed.
Fletcher, Fairness and Utility in Tort Theory, 85 Harv. L. Rev. 537, 572 (1972) refers to “the now rejected emphasis on the directness and immediacy of causal links, as well expressed in the Polemis case and Judge Andrews’ dissent in Palsgraf.”
See Keeton, Legal Cause in the Law of Torts, pps. 108-109 (1963), where he points out that the reason for product liability calls for the application of the same principles of causation as apply in negligence cases.
In Whitner v. Lojeski, 437 Pa. 448, 455, 263 A. 2d 889, 893 (1970), Mr. Justice Pomeroy made the point as follows: “One conld wish that the pronouncements of this Court on the subject over the years had been somewhat more lucid, more consistent, more forthright; had distinguished between cause in a factual or ‘philosophic’ sense and proximate or legal cause; had acknowledged that the concept, like that of negligence itself, was designed not only to permit recovery for a wrong, but to place such limits upon liability as are deemed socially or economically desirable from time to time.” [Footnote omitted.]
Cf. Andrews v. Jordan Marsh Co., 283 Mass. 158, 186 N.E. 71 (1933), where the court concludes that there is no reason for putting greater responsibility on a department store than on the owner of the dog.
Cf. Restatement 2d, Torts, §438, as to barm caused by animals negligently permited to wander, in which Oomment a expressly provides: “It does not apply to those animals which are customarily permitted to run at large.”