Abstract
The chapter begins with some background, introducing the concept of eidetic-constitutive rules and examining their prehistory, and then distinguishing them into deontic and adeontic eidetic-constitutive rules, while also drawing some other key distinctions. On the basis of these distinctions, we are shown that Searle’s constitutive rules are heterogeneous and that his “X counts as Y formula” fails to capture a variety of phenomena, including promises. Finally, the chapter stresses the semiotic and epistemological role of eidetic-constitutive rules. Here we are made to see that, since deontic eidetic-constitutive rules are conditions for the possibility and cognizability of peculiar forms of existence, they make Is-from-Ought derivations possible. [by eds.]