This concept is represented by a set of structural equations developed by Halpern and Pearl. Houdini observing a coin flip is used to demonstrate the impossibility of one form of this concept in Max Black’s“bilking argument.” The example of a sergeant shouting is used to demonstrate how “trumping” can lead to a“redundant” form of this concept by David Lewis, who proposed analyzing this concept in terms of (*) counterfactuals. David Hume asserted we understand this relation merely through “constant conjunction.” (10[1])Aristotle’s (10[2])Metaphysics proposed the formal, final, material, and efficient types of this relation. For 10 points, Hume (10[1])used striking billiard balls to analyze what relation that can lead to an effect, not to be confused with correlation? ■END■