There are broadly speaking two conceptions of how we perfrom speech act. One, the Austinian one, is that speech acts are purely conventional. So to promise is simly to utter the words ‘I promise…’ because there is a convention in English that says that saying ‘I promise…’ counts as making a promise. The other view is that (at least some) speech acts are performed via a kind of Gricean intention. This is the view that Strawson defended in his famous paper ‘Intention and Convention in Speech Acts’. On this view what makes something a promise is the intention that the speaker has in uttering it. In other words if I intend to be making a promise (and other conditions are met) then I count as making a promise.
Now, one thing I have noticed, is that when communicating via email it is easy to misinterpret what someone has ‘said’ (hence emoticons), which can lead to a quick escalation of tensions. How is this possible? It seems that the only way that this is possible is if the Strawsonian conception of speech acts is right. If performing a speech act is a purely convention act then there should be no question of whether a certain token, say of ‘I promise…’, is a promise, or a threat, or a guarentee, or what.
One may think, ‘ah, but there are different conventions governing that sentence type’ then one still needs to know what convention the ‘speaker’ intends to be conforming to. Either way the purely conventional nature of speech acts is brought into question.