Dissenting Opinion by
Judge Blatt :I respectfully dissent.
The significant parts of the medical expert’s testimony in this case are as follows:
A: He came to me with worsening since December of ’76 and it seemed like he had arthritis to-begin with but this was aggravated by the circumstances at work. (Direct Examination of Dr. Ved P. Gupta, lines 20-23, Appellant’s Reproduced Record at A-134.)
A: If his work involved, or he was exposed to sudden changes in temperature, severe cold, yes, his symptoms could increase pretty well. (Direct Examination of Dr. Ved P. Gupta, lines 14-16, Appellant’s Reproduced Record at A-136.)
A: I think with the sequence and time, I could make an opinion that it is possible that *209these changes in, or the circumstances that he was exposed to during his work could aggravate his symptoms, and it’s conceivable. If it did not happen, it’s something else. If he said he was exposed to these things, it’s conceivable they were aggravating factors. (Cross-Examination of Dr. Yed P. Gupta, lines 22-24 and 1-4, Appellant’s Reproduced Record at 159-160.) (Emphasis added.)
The majority opinion notes on page 4 [206] that the standard for admissibility of expert medical testimony on the subject of causation is: “It is sufficient that his medical expert, after providing a foundation, testify that in his professional opinion or that he believes or that he thinks the facts exist . . . even if the medical witness admits to uncertainty, reservation, doubt or lack of information with respect to medical and scientific detail.” The phrases “professional opinion” and “he believes”, however, are left undefined in the majority’s opinion. Yet a meaning, never previously accepted by this Court, is given to these phrases when applied to the facts.
The opinion of the medical expert here, it seems to me, amounted to nothing more than this: that it was conceivable that the condition to which the appellee was exposed to during his work could have aggravated his symptoms. And “conceivable” is defined by Webster, as: “1: capable of being conceived, imagined, or understood 2: logically possible.” Webster’s New International Dictionary 469 (1966).
Although it is clear that absolute certainty has never been previously required, the courts have required a minimal standard which is best articulated in Vorbnoff v. Mesta Machine Co., 286 Pa. 199, 206, 133 A. 256, 258 (1926): “that is to say, the witness would have to testify, not that the condition, of claimant might have, or even probably did, come from the acci*210dent, but that in his professional opinion the result in question came from the cause alleged.” And, although the majority attempts to articulate a standard similar to Vorbnoff, it broadens the threshold requirement for admissibility by allowing evidence predicated upon “conceivability” or “could have” standards, which are really the same as the “might have” or “probably did” standards rejected in Vorbnoff.
While recognizing the nuances of our language, which make it frequently difficult to frame a rule of law which conveys an intelligible standard, I cannot agree with the majority’s effort here to “clarify” the current standard, while at the same time introducing another very unclear element into the situation.
I would, therefore, reverse this order of the Board.