 According to the contextualists, the rules governing the shifts prohibit us from interpreting any instance of the induction step as having a true antecedent and a false consequent. The very process of trying to refute the induction step changes the context so that the instance will not come out false. Indeed, contextualists typically emphasize that each instance is true. Assent is mandatory. Consequently, direct attacks on the induction step must fail. One is put in mind of Seneca’s admonition to his student Nero: “However many you put to death, you will never kill your successor.”