In response to earlier posts on literature and 'subtraction,' a reader sends me the following passage from Umberto Eco's Open Work:

Any work of art can be viewed as a message to be decoded by an addressee. But unlike most messages, instead of aiming at transmitting a univocal meaning, the work of art succeeds precisely insofar as it appears ambiguous and open-ended. The notion of the open work can be satisfactorily reformulated according to Jakobson's definition of the "poetic" function of language." Poetic language deliberately uses terms in a way that will radically alter their referential function (by establishing, among them, syntactic relationships that violate the usual laws of the code). It eliminates the possibility for a univocal decoding; it gives the addressee the feeling that the current code has been violated to such an extent that it can no longer help. The addressee thus finds himself in the situation of a cryptographer forced to decode a message whose code is unknown, and who therefore has to learn the code of the message from the message itself." At this point, the addressee will find himself so personally involved with the message that his attention will gradually move from the signifieds, to which the message was supposed to refer, to the structure itself of the signifiers, and by so doing will comply with the demands of the poetic message, whose very ambiguity rests on the fact that it proposes itself as the main object of attention: "This emphasis of the message on its own self is called the poetic function..." When we speak of art as an autonomous process, as form for form's sake, we are stressing a particular aspect of the artistic message which communication theory and structural linguistics would define as follows: "The set (Einstellung) toward the MESSAGE as such, focus on the message for its own sake, is the POETIC function of language."* To this extent, ambiguity is not an accessory to the message: it is its fundamental feature. This is what forces the addressee to approach the message in a different fashion, not to use it as a mere vehicle (totally irrelevant once he has grasped the content it is carrying) but rather to see it as a constant source of continually shifting meanings—a source whose typical structure, begging relentlessly to be decoded, is organized so as to coordinate all the addressee's possible decodings and force him to repeatedly question the validity of their interpretations by referring them back to the structure of the message."

*In an endnote Eco adds: This does not mean that the signifieds (when they are there) do not count. On the contrary, the poetic message so effectively forces us to question the signifieds to which it refers that we often have to return to the message in order to find, in its patterns of signification, the roots of their problematic nature. Even in the case of preexisting signifieds (say, the Trojan War in the Iliad), the poetic message casts a new, richer light on them, thereby becoming a means to further knowledge.