Does A cause B? That has been a question statisticians and philosophers have been attempting to answer. It is indeed not a trivial task to prove causation between two events. Philosopher David Hume in his 1748 book ‘An Enquiry Concerning Human Understanding’ provided an idea to define causation, it was known as The Counterfactual Theory of Causation. Here is an attempt to explain the counterfactual theory of causation.