What is the primary standard used to establish actual causation in tort law?

The primary standard used to establish actual causation in tort law is the "substantial factor" test. This standard focuses on whether the defendant's conduct was a substantial factor in bringing about the plaintiff's injury. It acknowledges that there can be multiple causes contributing to an injury, and as long as the defendant's actions were significant enough to contribute to the result, actual causation can be established.

The substantial factor test is particularly useful in situations involving multiple causative agents where determining a singular cause would be challenging. For example, if a plaintiff's injury was influenced by both the defendant's actions and other independent factors, the question would be whether the defendant’s conduct was a substantial factor in causing the harm. If it was, then the defendant can be held liable.

In contrast, proximate cause is more about the legal consequences of the actions rather than the factual cause. Foreseeability involves determining whether the harm was a foreseeable result of the defendant's actions, which relates more to proximate cause than actual causation. A negligent act simply refers to the behavior that may have caused harm, but it does not itself establish causation. Thus, the substantial factor standard is key to illustrating the link between the defendant's conduct and the plaintiff's injury in