 A second passerby (who happens to be an Automobile Association man) proffers a different explanation: he holds up a loose cable and says “Look here, Sir, you are running on three cylinders” (EM 1998: 303). The first explanation invokes the sense of causation that belongs to the theoretical sciences of nature, sense III. The second explanation invokes the sense of causation that belongs to the practical sciences of nature, sense II. The choice between these explanations, for Collingwood is determined by the nature of the question asked. As he puts it: