Opinion ID: 2143014
Heading Depth: 1
Heading Rank: 5

Heading: But For Instruction on Causation.

Text: The portion of the charge to the jury to which plaintiff here objects is contained in the first sentence of the following paragraph of the charge: You are instructed that before you can find that the collision of March, 1959, was a cause of the amputation in August of 1959 you must find that the amputation would not have been required but for the collision, or that it would have been required even though the collision had not occurred. You must be satisfied that the injuries received in the collision, if any, were substantial factors in causing the amputation. That is that the results of the collision became factors and substantially contributed to the amputation as a natural result. The word `substantial' as used here means that the collision must have had such an effect in producing the amputation as to lead reasonable men and women to regard it as a cause. If the results of the collision, to Mr. Chapnitsky, were so insignificant that no ordinary mind would think of them as causes, then they would not be substantial factors in producing the amputation. A discussion and criticism of the but for test of causation is found in Prosser, Law of Torts (2d ed.), pp. 220, 221, sec. 44. The author concedes that it is a satisfactory test to apply in the great majority of cases but that it is inadequate in the following type of situation:  If two causes concur to bring about an event, and either one of them, operating alone, would have been sufficient to cause the identical result, some other test is needed. Two motorcycles simultaneously pass the plaintiff's horse, which is frightened and runs away; either one alone would have caused the fright. A stabs C with a knife, and B fractures C's skull with a rock; either wound would be fatal, and C dies from the effects of both. The defendant sets a fire, which merges with a fire from some other source; the combined fires burn the plaintiff's property, but either one would have done it alone. In such cases it is clear that each cause has played a part in the result, and it is also clear that neither can be absolved from responsibility upon the ground that the harm would have occurred without it, or there would be no liability at all. Ibid. Plaintiff contends that the instant case falls within the group of cases described in the above-quoted extract from Prosser. His contention is apparently based upon the premise that there were two causes of the amputationthe preexisting osteomyelitis infection and the accident of March 16, 1959. In the above-quoted extract, however, Prosser is not discussing all cases in which two causes produce an end result, but only those limited few in which either cause alone would have been sufficient to produce such an end result. The instant case is clearly not of that limited type because, under the evidence the minor jar of the instant accident could never have caused the amputation without the preexisting osteomyelitis infection and the condition resulting from the osteotomy performed a month before. On the other hand, there was conflicting evidence as to whether the preexisting osteomyelitis infection alone, without the intervention of the March 16, 1959, accident, would have caused it. The but for test instruction was therefore not erroneous because if the osteomyelitis infection alone, without the intervention of the March 16, 1959, accident, would have resulted in the amputation, then such accident was not a  substantial factor in causing the amputation. The substantial-factor test of causation is the one approved by Prosser and by this court. Pfeifer v. Standard Gateway Theater, Inc. (1952), 262 Wis. 229, 55 N. W. (2d) 29. See also Campbell, Duty, Fault, and Legal Cause, 1938 Wisconsin Law Review, 402. This test was also set forth in the above-quoted paragraph of the charge following the sentence containing the but for test.