ABSTRACT
Statistical reasoning must be capable of eliminating chance when the probability of events gets too small. If not, chance can be invoked to explain anything. Scientists rightly resist invoking the supernatural in scientific explanations for fear of committing a God-of-the-gaps fallacy (the fallacy of using God as a stopgap for ignorance). Yet without some restriction on the use of chance, scientists are in danger of committing a logically equivalent fallacy—one we may call the chance-of-the-gaps fallacy. Chance, like God, can become a stopgap for ignorance. For instance, in the movie This is Spinal Tap, one of the lead characters remarks that a former drummer in his band died by spontaneously combusting. Any one of us could instantly spontaneously combust if all the fast-moving air molecules in our vicinity suddenly converged on us. Such an event, however, is highly improbable, and we do not give it a second thought.
