Legal Definitions - factual cause

Factual cause, often referred to as "but-for" cause, is a fundamental concept in law, particularly in torts (civil wrongs) and criminal law, used to determine if a defendant's action or inaction played a direct role in bringing about a particular outcome or injury. It asks whether the harm would have occurred but for the defendant's conduct. If the harm would not have happened without the defendant's actions, then those actions are considered a factual cause of the harm. This is the initial step in establishing causation, preceding the determination of legal (or proximate) cause.

Here are some examples illustrating factual cause:

• Example 1: Construction Site Accident

  A construction company, BuildCo, fails to properly secure a scaffolding plank on a building site, violating established safety regulations. An employee, Sarah, steps onto the plank, which then slips, causing her to fall several feet and break her leg.

  Explanation: To determine factual cause, we apply the "but-for" test: "Would Sarah have broken her leg but for BuildCo's failure to properly secure the scaffolding plank?" The answer is no; if the plank had been secured as required, it would not have slipped, and Sarah would not have fallen. Therefore, BuildCo's negligence in securing the plank is a factual cause of Sarah's injury.

• Example 2: Food Contamination

  A restaurant, The Gilded Spoon, serves a dish containing undercooked chicken to a customer, Mark. Mark consumes the dish and subsequently develops severe food poisoning, requiring emergency medical treatment and hospitalization.

  Explanation: Applying the "but-for" test: "Would Mark have developed food poisoning *but for* The Gilded Spoon serving undercooked chicken?" If the chicken had been properly cooked to the safe internal temperature, the harmful bacteria would have been eliminated, and Mark would not have gotten sick from that meal. Thus, the restaurant's action of serving undercooked chicken is a factual cause of Mark's food poisoning.

• Example 3: Defective Product

  A manufacturer, TechGadget Inc., produces a batch of smartwatches with a known battery defect that can cause the devices to overheat and potentially ignite. Lisa purchases one of these smartwatches. While charging it overnight, the defective battery overheats, causing a small fire that damages her nightstand and an antique clock.

  Explanation: We ask: "Would Lisa's property have been damaged by fire *but for* TechGadget Inc. manufacturing a smartwatch with a defective battery?" If the battery had not been defective, it would not have overheated and caught fire. Therefore, the defective battery manufactured by TechGadget Inc. is a factual cause of the damage to Lisa's property.