Das normative "ist" und das konstatiere "soll"

Despite the fact that Aristotle and Frege/Russell differ in how to understand the ambiguity in the meaning of the word "is", their theories share a common feature: "is" does not have a normative meaning, but a constative meaning. This paper, however, shows (1) that there is a normative meaning of "is" (and correspondingly a constative meaning of the word "ought") and (2) that the ambiguity of "is" is itself ambiguous. Furthermore, the paper proposes (3) a performative criterion for making a distinction between constative and normative "is". Thereby, it is possible to attack Searle's famous argument against Hume's law.