The dispute between these parties has been before this court on a previous occasion: Hamil v. Bashline, 224 Pa.Super. 407, 307 A.2d 57 (1973), allocatur denied, 224 Pa.Super. xxxvi. The facts, detailed in the earlier opinion, may be briefly summarized as follows: Plaintiff-appellant’s decedent, suffering from severe chest pains, was taken to the defendant-appellee hospital. One of the doctors on duty ordered the taking of an EKG. When informed that the EKG machine had malfunctioned, the doctor ordered the use of another EKG machine and then left the hospital. Another machine was not located, and the decedent was taken to Dr. Raymond Saloom’s office in Harrisville, Pennsylvania, located four miles from the hospital. He died while Dr. Saloom attempted to take an EKG.
In the resulting wrongful death and survival actions, the lower court, at the conclusion of the first trial, directed a verdict in favor of the appellees, basing its decision on the purported failure of the appellant to establish *231a causal connection between the appellees’ conduct and the decedent’s death. On appeal, this court reversed the judgment of the lower court and remanded the case for a new trial, basing its decision on § 828 of the Restatement (Second) of Torts (1965), infra. The new trial resulted in a jury verdict for the appellees, and from that judgment the appellant appeals. We affirm and hold the following: (1) proof that a defendant’s conduct increased the risk of harm is not, under § 323, proof that the conduct caused the harm; (2) § 323 does require proof of a causal connection between defendant’s conduct and plaintiff’s harm; (3) in this case, the requisite causal connection was not shown.
Appellant contends that she is entitled to another new trial because the lower court erred in its instruction to the jury concerning causation. However, before we reach the issue of the validity of the court’s instructions, we must answer a contention of appellees. Appellees, in effect, ask that the previous decision in this case be reconsidered. If this court’s previous decision was erroneous, then appellees were entitled to the directed verdict they received in the lower court, and any error in the second trial was harmless. Cf. Jaski v. West Park Daily Cleaners and Dyers, Inc., 334 Pa. 12, 5 A.2d 105 (1939); Pears v. Shannon, 329 Pa. 278, 198 A. 307 (1938).
At the first trial, appellant’s expert, Dr. Cyril H. Wecht, opined as to the causal connection between appellees’ conduct and the resulting harm:
“In my opinion, the substantial chances that Mr. Hamil would have had for survival were terminated, were taken away from him by the failure by the initial hospital to have given him the kind of treatment and examination which he should have had under the circumstances that you have outlined.”
Dr. Wecht testified that, in his opinion, given proper medical care, the decedent would have had a 75% chance of survival.
*232The trial judge struck Dr. Wecht’s testimony and directed a verdict for the appellee, reasoning that “the testimony did not meet the standard of expert testimony requiring an opinion based on reasonable medical certainty that the death was in° fact caused by defendant’s failure to exercise reasonable care.” On appeal, this court held that although the testimony was insufficient to prove causation under the normal standards for expert testimony, it was sufficient to allow the case to go to the jury under § 323 of the Restatement (Second) of Torts (1965). That section provides:
“One who undertakes, gratuitously or for consideration, to render services to another which he should recognize as necessary for the protection of the other’s person or things, is subject to liability to the other for physical harm resulting from his failure to exercise reasonable care to perform his undertaking, if
(a) his failure to exercise such care increases the risk of such harm, or
(b) the harm is suffered because of the other’s reliance upon the undertaking.”
There is language in this court’s earlier opinion indicating that under § 323, the causal connection between a defendant’s conduct and a plaintiff’s harm may be proved solely by evidence that the defendant’s conduct increased the risk of harm:
“Subsections (a) and (b) permit that causal connection to be proved by evidence that defendant’s failure increased the risk of such harm as was suffered by plaintiff or by evidence that the harm was suffered because of reliance on the defendant’s undertaking.” 224 Pa.Super, at 415, 307 A.2d at 61,
and
“Section 323 . . . [allows] . . . causal connection between the death and defendant’s conduct to be proved by evidence that the risk of death was in*233creased by defendant’s failure to exercise reasonable care . . . .” 224 Pa.Super. at 417, 307 A.2d at 62.
However, immediately following the above statement, the court acknowledged that the traditional causal connection must be found by the jury before liability may follow:
“The defendant is not, under Section 323, liable merely for having increased the risk of death, but the evidence of the increased risk of death is under subsection (a) of that section for the jury’s consideration on the factual issue whether the death was caused by defendant’s failure to use reasonable care.” 224 Pa.Super. at 417, 307 A.2d at 62.
Thus, the opinion indicates that after receiving evidence that the negligent conduct increased the risk of harm, the jury may conclude that the negligent conduct caused the harm. The problem with this theory is that an expert’s testimony that is less than certain leaves the jury with insufficient evidence to make that conclusion.
I.
By allowing an expert to testify as to causation, it is assumed that the jury does not have sufficient knowledge to confront the causation question on its own. Because a jury’s verdict may not be based on speculation, an expert is required to testify with certainty, thus exposing the jury to facts which support a finding of causation. See McMahon v. Young, 442 Pa. 484, 276 A.2d 534 (1971). If an expert testified that conduct increased the risk of harm and may have, in fact, caused the harm, from what facts can the jury conclude that the conduct in fact did cause the harm ? If the only evidence of causation is expert testimony, and if the expert, with all his training and experience, can only conclude that the conduct may have caused the harm, any conclusion as to causation on the part of the jury would necessarily be *234based on speculation. It must therefore be admitted that a jury cannot be permitted to find causation solely from expert testimony of increased risk. The question then becomes whether § 323 purports to allow liability to attach to conduct which has not necessarily caused the harm, but which has increased the risk of harm which in fact results.
II.
There can be no doubt that such an eventuality is not contemplated by § 323, and that § 323 requires a causal connection between a defendant’s conduct and a plaintiff’s harm. The section provides that an actor who meets the conditions of the section “is subject to liability to the other for physical harm resulting from his failure to exercise reasonable care.....” (emphasis added). Webster’s Third New International Dictionary (1966) defines “result,” inter alia, as: “to proceed, spring, or arise as a consequence, effect, or conclusion. . . .” If an event “arises as a consequence” of another event, if an event “results from” another event, then one of the events must have caused the other. This was implicitly recognized by the Supreme .Court of Pennsylvania in Lambert v. Soltis, 422 Pa. 304, 221 A.2d 173 (1966), wherein the court used the words “as a result of” in referring to causation.
Thus, independent of subsection (a) and (b),1 § 323 contains a requirement of causation that cannot be met solely by evidence of increased risk. In addition to increasing the risk of harm, the conduct must have caused the harm. Therefore, we must decide whether *235appellant’s expert testimony sufficiently met the causation requirement of § 323, i. e., whether it stated in sufficiently definite terms that the decedent’s death resulted from appellees’ failure to exercise reasonable care.
III.
In Pennsylvania, expert testimony evidencing a causal link must conform to a standard of certainty. “ [A] n expert witness [must] testify not that the injury in question might have been or even probably was caused by the alleged negligence, but . . . that in his professional opinion the result in question came from the cause alleged.” Houston v. Canon Bowl, Inc., 443 Pa. 383, 386, 278 A.2d 908, 910 (1971). See also McMahon v. Young, supra; Niggel v. Sears-Roebuck & Co., 219 Pa.Super. 353, 281 A.2d 718 (1971).
The reason for this rule springs from two fundamental legal precepts. The first has already been mentioned: a jury cannot be permitted to speculate on the issue of causation, but must be given some concrete evidence on which to ground a conclusion.
The second precept is older and better established than the first: liability will not be imposed unless the plaintiff proves that the defendant’s conduct was the cause of the harm in question. Where expert testimony can do no more than establish that the defendant’s conduct probably caused the harm, any imposition of liability is an abrogation of these precepts. In such a situation, liability would be imposed for negligence, but for negligence that has not been proved to have caused any harm.
In this case, Dr. Wecht, an eminently qualified physician, testified unequivocally that the hospital’s failure to provide the decedent with the kind of treatment that he should have had under the circumstances demonstrated an absence of reasonable care. He also testified unequivocally that the decedent’s substantial chances for survival were terminated by the hospital’s failure to provide him *236with that treatment. Finally, Dr. Wecht testified that, even given proper treatment, it is not certain that the decedent would have survived. According to Dr. Wecht, he would have had only a 75% chance of survival.
The crux of appellant’s position is that the decedent died because appellees unreasonably failed to save him. Appellant is not attempting to show that the decedent’s death was affirmatively caused by appellees, but rather that his life was not saved as a result of appellees’ negligent conduct. In this context, an expert would have to testify that, given proper medical treatment, Mr. Hamil would have survived. Dr. Wecht did not so testify.
It may be that no expert can ever testify that a person would have survived a heart attack. If it is wrong to forbid recovery under such circumstances, then the fault lies not within the requirement that expert testimony be certain, but within the requirement that there be a causal link between defendant’s conduct and plaintiff’s harm. If causation is to be regarded as an element of a cause of action for negligence, then expert testimony must meet a standard of certainty. The expert testimony in this case did not meet that standard and was properly stricken.
In view of the fact that appellees were entitled to a directed verdict, we need not consider the trial errors alleged by appellant. Hamil v. Bashline, 224 Pa.Super. 407, 307 A.2d 57 (1973), is overruled. The judgment of the lower court in favor of appellees is affirmed.
HOFFMAN, J., files a concurring opinion. JACOBS, J., concurs in the result. CERCONE, J., files a dissenting opinion, in which SPAETH, J., joins. SPAETH, J., files a dissenting opinion.. Subsections (a) and (b) would seem to be conditions to liability. The actor is liable under § 323 only if “(a) his failure to exercise such care increased the risk of such harm, or (b) the harm is suffered because of the other’s reliance upon the undertaking.” On this appeal, no issue concerning either of these conditions has been raised.