 Suppose that a student is considering whether to study for an exam. He reasons that if he will pass the exam, then studying is wasted effort. Also, if he will not pass the exam, then studying is wasted effort. He concludes that because whatever will happen, studying is wasted effort, it is better not to study. This reasoning errs because studying raises the probability of passing the exam. Deliberations should take account of an act’s influence on the probability of its possible outcomes.