Closure

When people learn normative systems, they do so based on limited evidence. Many of the possible actions that are available to an agent have never been explicitly permitted or prohibited. But people will often need to figure out whether those unspecified actions are permitted or prohibited. How does a learner resolve this incompleteness? It seems that at least for many people in many contexts, there is an assumption that if an action-type is not expressly forbidden, then acts of that type are permitted. This “closure principle” is one of Liberty. But how might such a principle be acquired? This chapter argues that the statistical technique of pedagogical sampling provides an answer. If one is taught a rule system via a set of prohibitions, this provides reason to think that the set of actions in the domain that are not mentioned in the prohibitions are permitted.