In philosophy and linguistics, the sense of a linguistic expression, sometimes understood in contrast to its referent. For example, the expressions the morning star and the evening star have different meanings, though their referent (Venus) is the same. Some expressions have meanings but no referents (the present king of France) or referents but no meanings (that). The literal or conventional meaning of an expression may differ from what a speaker of that expression means by uttering it on a particular occasion; this is the case with similes, statements uttered ironically, and statements that convey various conversational implicatures, as in the following examples: She entered the house and shot him implicates that she shot him in the house after she entered it, though this is not part of the sentence's literal meaning; John has three sons implicates that John has no more than three sons, though again the sentence does not literally say this. Other non-literal aspects of meaning include the potential for carrying out various speech acts (seespeech act theory); e.g., uttered in the appropriate circumstances, the sentence I christen thee the Joseph Stalin, constitutes the act of naming a ship, and the sentence I am cold constitutes a request to close the window. See alsopragmatics; semantics.