Some followers of Austin, such as David Holdcroft, view illocutionary force as the property of an utterance to be made with the intention to perform a certain illocutionary act—rather than as the successful performance of the act (which is supposed to further require the appropriateness of certain circumstances). According to this conception, the utterance of "I bet you five pounds that it will rain" may well have an illocutionary force even if the addressee doesn't hear it. However, Bach and Harnish assume illocutionary force if, and only if this or that illocutionary act is actually (successfully) performed.