 By an account of assertion is here meant a theory of what a speaker does (e.g., expresses a belief) in making an assertion. According to such accounts, there are deep properties of assertion: specifying those properties is specifying what asserting consists in. There must also be surface properties, which are the properties by which a competent speaker can tell whether an utterance is an assertion, for instance that it is made by means of uttering a sentence in the indicative mood.