REASONING ABOUT CAUSES
If our car goes dead in the middle of rush-hour traffic just after its 20,000-mile checkup, we assume that there must be some reason why this happened. Cars just don’t stop for no reason at all. So we ask, “What caused our car to stop?” The answer might be that it ran out of gas. If we find, in fact, that it did run out of gas, then that will usually be the end of the matter. We will think that we have discovered why this particular car stopped running. This reasoning is about a particular car on a particular occasion, but it rests on cer- tain generalizations: We are confident that our car stopped running when it ran out of gas, because we believe that all cars stop running when they run out of gas. We probably did not think about this, but our causal reasoning in this particular case appealed to a commonly accepted causal generalization: Lack of fuel causes cars to stop running. Many explanations depend on causal generalizations.
Causal generalizations are also used to predict the consequences of partic- ular actions or events. A race car driver might wonder, for example, what would happen if he added just a bit of nitroglycerin to his fuel mixture. Would it give him better acceleration, blow him up, do very little, or what?
