  (2) New problems arise when we have mixed inferences, involving indicative as well as imperative premises. The simplest way of extending a logic of satisfaction to these is by the following rule: a set of premises entails a conclusion if the premises cannot be true (if indicative) or satisfied (if imperative) without the conclusion being true or satisfied also. However, we also need restrictive rules of which an example (already stated in 1952: 28) would be that no imperative conclusion can be drawn from purely indicative premises—but that is doubtless too simple. Take an example from Aristotle’s De Motu Animalium (7, 701a19–22). It involves reasoning from one intention to another. Given Hare’s willingness to represent intentions as self-addressed imperatives, we can rewrite it as follows: