Torts I


A reasonably close causal connection between the conduct and the resulting injury is commonly called causation.

Causation has two elements: causation in fact and proximate cause.

Causation in Fact

Causation in fact is generally determined by the "but for" test.

But For Test

Causation exists when the damage more likely than not would not have occurred but for the defendant's actions.

In statistical evidence, the risk of the harm occurring must have more than doubled.

Substantial factor test applies in "loss of a chance" cases in medical malpractice, based on the jurisdiction.

In cases where two or more actively operating forces, only one of which the defendant was responsible for, combine to bring about the harm, the "substantial factor" test applies instead.

Substantial Factor

Under the "substantial factor" test, causation is determined by whether or not the defendant's act was a "substantial factor" in causing the harm.

A substantial factor in causing harm is a factor that a reasonable person would consider to have contributed to the harm. It must be more than a remote or trivial factor. It does not have to be the only cause of the harm.

For hazardous chemical cases, to be a substantial factor requires "evidence of exposure to a specific product on a regular basis over some extended period of time in proximity to where the plaintiff actually worked."

When two or more causes combine to cause an injury, the defendant is a cause in fact if the defendant's conduct was a substantial factor in causing the injury.

Market Share Liability

When a group of defendants produce a substantial share of the market share of a drug, they may be held liable for harms resulting therefrom for their approximate portion of market share when the specific manufacturer is unknown. Sindell.

This usually only applies to DES cases.

Proximate Cause

The conduct must not have only caused the harm, it must have also been the proximate cause.

There are four different tests that are used in various types of circumstances to determine if there is proximate cause:

  1. Reasonable Foreseeability Rule

    The general test for proximate cause is whether or not it was reasonably foreseeable that the defendant’s conduct would injure the plaintiff. Wagon Mound No. 1.

    An injury doesn't have to be likely or probable in order to be foreseeable.

    The risk to be reasonably perceived defines the duty to be obeyed.

  2. Direct Cause

    Another rule used sometimes in determining the issue of proximate cause is the direct cause rule. Polemis. The direct cause rule provides that a defendant is responsible for all consequences which follow in unbroken sequence, without an intervening efficient cause, from the original negligent act. Such consequences are natural and proximate, and the defendant’s negligence is the proximate cause. The defendant does not have to foresee the exact kind of harm as long as some harm was foreseeable.

  3. Palsgraf Rule

    The rule from Palsgraf is often used when addressing proximate cause issues when the plaintiff is not directly involved in the event or accident that leads to his injury. Palsgraf provides that proximate cause extends liability to those whose conduct harms persons within the zone of the reasonably foreseeable plaintiff. The concept of foreseeability limits liability to the consequences of an act that can reasonably be foreseen. If a person is not a reasonably foreseeable plaintiff, a defendant cannot reasonably foresee an unreasonable risk of harm to him; therefore, the defendant’s negligence would not be the proximate cause of an unforeseeable plaintiff’s injury.

    This is another take on the direct cause rule and uses the reasonable foreseeability rule basically.

  4. A defendant is responsible for harms that have only a small risk if the resulting damage is great. A defendant is liable for a risk that does not have a disadvantage to preventing it, no matter how small the risk is. A defendant may be liable for even a small risk if a great harm would result. Wagon Mound No. 2.
Eggshell Skull Rule

The "eggshell skull" rule states that one is liable for all physical injuries even if another person wouldn't have suffered those injuries. Simply put, a defendant takes the plaintiff as he find him.

Intervening Cause

When a third person intervenes between the defendant's conduct and the plaintiff's injury, liability turns upon whether the intervening act is a normal or foreseeable consequence of the situation created by the defendant's negligence.


A superseding act breaks the causal nexus of proximate cause. An intervening act may well be superseding if it is extraordinary under the circumstances, not foreseeable in the normal course of events, or independent of or far removed from the defendant's conduct.

Rescue Doctrine

To achieve rescuer status one must demonstrate:

  1. The defendant was negligent to the person rescued and such negligence cause the peril or appearance of peril to the person rescued.
  2. The peril or appearance of peril was imminent.
  3. A reasonably prudent person would have concluded such peril or appearance of peril existed.
  4. The rescuer acted with reasonable care in effectuating the rescue.

The rescue doctrine does not apply to professional rescuers for normal risks of their employment when they are working.