The Asymmetry Of Causation Through Causal Connection
Two variables A and B are "causally connected" if either A is a cause of B, B a cause of A, or a third variable causes them both. If causation is transitive, then it turns out that everything causally connected to X is connected to its effects, but not everything connected to Y is connected to its causes. When X → Y, everything causally connected to X is causally connected to Y (Fig. 7a), but something causally connected to Y is not necessarily causally connected to X (Fig. 7b).
Science EncyclopediaScience & Philosophy: Categorical judgement to ChimaeraCausation - Modern Theories Of Causation, The 1970s And Early 1980s: The Age Of Causal Analyses, Event Causation Versus Causal Generalizations