 The study of speech acts goes back to Austin (1957) and Searle (1969). Both emphasise that using language is to perform certain acts. Moreover, there is not just one act but a whole gamut of them (Austin himself puts the number in the magnitude of \(10^3)\). The classification he himself gives involves acts that are nowadays not considered as part of a separate science: the mere act of uttering a word (the phatic act) or sentence is part of phonetics (or phonology) and only of marginal concern here. By contrast, the illocutionary and perlocutionary acts have been the subject of intense study. An illocutionary act is the linguistic act performed by using that sentence; it is inherently communicative in nature. By contrast, the perlocutionary act is an act that needs surrounding social contexts to be successful. The act of naming a ship or christening a baby, for example, are perlocutionary. The sentence “I hereby pronounce you husband and wife” has the effect of marrying two people only under certain well-defined circumstances. By definition, perlocutionary acts take us outside the domain of language and communication.