This entry unfolds in three parts. We start with hypothetical publicity, and singularly with Immanuel Kant’s publicity test, contrasting his position with the one of Henry Sidgwick and looking both at the justification and implications of the Kantian test (§1). More precisely, our focus in this first part will be on two questions. First, what (if anything) justifies the importance of this test? Second, what are its implications for moral and political philosophy in general and for actual publicity in particular? Hypothetical publicity may appear to some readers as the only genuinely philosophical development on publicity, which is why we examine it first.