Abstract
In this paper my primary aim is to present a logical system of practical reasoning that can be used to assess the validity of practical arguments, that is, arguments with a practical judgment as conclusion. I begin with a critical evaluation of other approaches to this issue and argue that they are inadequate. On the basis of these considerations, I explain in Sect. 2 the informal conception of practical validity and introduce in Sect. 3 the logical system P , which is an extension of propositional logic and can be used to assess the validity of a wide range of practical arguments. In the last section, I apply this system to some examples of practical reasoning in order to demonstrate how it can be used in practice.