The present thesis puts forward a deflationist theory of singular definite descriptions. According to this theory, an utterance of the F is G only expresses the proposition that at least one F is G. The thesis examines Russells theory of definite descriptions and Donnellans distinction between referential and attributive uses of definite descriptions and argues that Donnellan’s distinction is not at odds with a Russellian (i. e., unitarian and quantificational) approach to definite descriptions. Based on methodological considerations, the thesis claims that it is not necessary to postulate a distintic semantic interpretation for the referential use of definite descriptions and that these are best seen as a kind of pragmatic phenomena. However similar considerations suggest that the implication of uniqueness associated with some uses definite descriptions is not – in general - semantic either. Definite descriptions are quantificational expressions but there are no independent reasons for holding that uniqueness is part of their semantic content. Therefore an utterance of the F is G can be used to communicate that that there is at most one F despite the fact that this is not part of the proposition the utterance expresses.