Tort law is easy to describe at a general level and hard to define more precisely. Tort comes from a Latin word meaning “twisted” or “turned aside,” so a tort is an act that is turned aside from the standard of proper conduct—a wrongful act. If you punch your neighbor in the nose, run over a pedestrian by driving carelessly, or injure a customer by serving burning hot coffee, you have committed a tort. (Some torts, not discussed here, involve only economic harm and not physical injury, such as falsely accusing someone of being a crook or using fraud to induce them to enter into a financial transaction.) All of these are wrongful acts for which the victim can receive an award of money damages.

Tort law is divided into three categories: intentional torts, negligence, and strict liability. An intentional tort is when the person causing the harm meant to do so. Negligence involves carelessness. Strict liability holds the actor responsible even though he did not mean to harm the victim and exercised care in trying to avoid the harm. Of these, the easiest category to understand is intentional torts, where the prototypical tort is known as battery.

When Yuki punches Hiro in the nose, pushes him down a flight of stairs, or runs him over with his car, it constitutes the intentional tort of battery. Battery protects the integrity of a person’s body against intentional invasions. Providing a remedy for battery serves the policies of tort law. We want to deter Yuki and people like him from punching others, and if Hiro has to go to the doctor because of his injuries, it is fair that Yuki compensate him for his loss.

Simple enough. But of course, the law is seldom that simple. Intentional torts are wrongful because the tortfeasor intended to cause harm to the victim. (Tortfeasor is an elegant legal term for someone who commits a tort; substitute “wrongdoer” if you like.) But what does it mean to intend harm? And what kind of harm is required?