First Principles of Business Law

6. Causation

6.2.3. Single causes of harm

Case study: A is walking along a path. She is looking where she is going and keeping to her side of the path. B, a cyclist using the same footpath and going in the same direction as A, is cycling fast with his head down in an effort to attain greater speed. He does not see A. B collides with A from behind, knocking her down and injuring her.

Consider both of the arguments below. Which of them do you think is correct?

(a) In most cases, there is no 'single cause' of events. In this case the collision happened partly because A was on the path at that time and in that place. Her presence therefore contributed to the collision, and it can't be said that the collision happened only because of A's negligent conduct.

(b) The presence of A on the path was not in itself negligent conduct and should not be taken into account as contributing to the harm. It is clear that the harm to A was caused by B going too fast and not keeping a proper lookout. The collision only happened because of B's negligent conduct.