Actual Cause Definition

An element of causation that asks whether an act or event was a cause-in-fact or but-for cause of some outcome.

For example, assume that Dave was texting while driving. He ran a red light and collided with another vehicle. Dave's distracted driving was the actual, or but-for cause, of the collision. But for Dave's texting, he probably would have seen the light and come to a safe stop.

The problem with actual cause is that any two events can be linked together through a chain of but-for causation. Continuing with our example, Dave wouldn't have run the red light had he never been born. Dave's mother giving birth to him is also a but-for or actual cause of the collision.

To resolve this issue, the law uses proximate cause to break the chain of actual causation when it becomes too attenuated.

(See also: causation, proximate cause)