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3.1-4  Proximate Cause - Substantial Factor

Revised to January 1, 2008

Negligence is a substantial factor in bringing about an injury if it contributes materially to the production of the injury.

<Read the next section only where one or more of the parties requests it and one or more of the theories of causation upon which the case has been presented fairly requires that it be given to ensure that the jurors are not misled.> 

Negligence contributes materially to the production of an injury if its causative effects remain in active operation until the moment of injury, or at least until the setting in motion of the final active injurious force which immediately produces or precedes the injury.  By this definition, negligence which makes only a remote, a trivial or an inconsequential contribution to the production of an injury is not a substantial factor in bringing about the injury, and thus is not a proximate cause of the injury.

Authority

Doe v. Manheimer, 212 Conn. 748, 757-58 (1989) (quoting Kowal v. Hohfer, 181 Conn. 355, 359-60 (1980), as follows: "The 'proximate cause' requirement tempers the 'expansive view of causation [in fact] . . . by the pragmatic . . . shaping [of] rules which are feasible to administer, and yield a workable degree of certainty.  1 Harper & James, Torts § 20.4, p. 1133.  Remote or trivial [actual] causes are generally rejected because the determination of the responsibility for another's injury is much too important to be distracted by explorations for obscure consequences or inconsequential causes'"); Ferndale Dairy, Inc. v. Geiger, 167 Conn. 533, 538 (1975) ("The test is whether the defendant's conduct was a substantial factor in causing the plaintiff's injuries.  To be such a fact the cause must have continued down to the moment of the damage or, at least, down to the setting in motion of the final active injurious force which immediately produced or preceded the damage"); Smiroff v. McNerney, 112 Conn. 421, 424-26 (1930) (finding no error in a jury instruction which defined proximate cause as any act or occurrence which "substantially or materially contributed to produce" the injuries suffered, because:  "The word 'contribute' carries in itself the significance of a causal connection between the negligence and the injury.  Whatever the phrases we have used to qualify it, the purpose has been to distinguish those negligent acts or omissions which play so minor a part in producing the injuries that the law does not recognize them as legal causes. . . .   In Coogan v. Aeolian Co., [87 Conn. 149], 156 [(1913)], we pointed out that the phrases, 'substantially and proximately' contributing and 'essentially or materially' contributing are two forms expressive of one thought. . . ."  On that basis the court concluded that the phrase "substantial factor in producing the plaintiff's injuries," as used in Mahoney v. Beatman was "tantamount" to the phrase "substantially or materially contributed to produce" the plaintiff's injuries); Mahoney v. Beatman, 110 Conn. 184, 198-99 (1929) (first equating the terms "substantial factor" and "material contribution" for the purposes of defining and establishing proximate cause).