In the view of Searle and Vanderveken, illocutionary negations change the type of illocutionary act. To perform an illocutionary act is to use a locution with a certain force. That explains why illocutionary force can be deployed without exerting muscular effort. Searle used this notion of ""direction of fit"" to create a taxonomy of illocutionary acts. While illocutionary acts relate more to the speaker, perlocutionary acts are centered around the listener. The concept of an illocutionary act is central to the concept of a speech act. Thus, promising is an illocutionary act in the present sense. For Austin, "doing things" with words means, first and foremost, deploying "illocutionary" force. They will have a locutionary sense or meaning, an illocutionary force, and a perlocutionary result. "Uptake" is the illocutionary response elicited by particular situations.