Philosophy. All events have causes and are consequences of earlier events. See causation- determinism. Causality means that something has a cause-effect relationship with something else, or that something causes another. It is difficult to prove causality because you need to prove not only that there is a relationship between two things but that it is a cause-effect relationship. For example, smoking causes lung cancer, is a statement of causality, because it says that one thing is actually causing another.