For Saussure, the signified was one of the two parts of the sign (which was indivisible except for analytical purposes). Saussure's signified is the mental concept represented by the signifier (and is not a material thing). This does not exclude the reference of signs to physical objects in the world as well as to abstract concepts and fictional entities, but the signified is not itself a referent in the world (in contrast to Peirce's object). It is common for subsequent interpreters to equate the signified with 'content' (matching the form of the signifier in the familiar dualism of 'form and content').