Summary: For all its history, deontic logic had to face the question whether it is a logic of descriptions or a logic of prescriptions, namely of imperatives. In this chapter, I describe how the idea that there is a ‘logic of imperatives’ first came about, what proposals there have been to explain it and what problems it has had difficulties to solve. I argue that the idea of a logic of imperatives rests on a mistaken parallelism between imperative and indicative language and that there is, as a matter of fact, no such logic. However, we can argue about what ought to be done or need not be done according to given imperatives, and appeal to existing imperatives to motivate new ones.
For the entire collection see [Zbl 1309.03001].