With all the usual disclaimers about postmodernism in place (i.e. not being a single approach, including a variety of contrasting ideas, etc.)…
The "culprit" here is the wide reception of French literary critic Roland Barthes and his essay The Death of the Author from 1967.
Taking cue from similar ideas by earlier writers, the essay questions the role that authorial intent can play in the interpretation of texts.
Barthes' argues for his proposition in a variety of ways:
- Skeptical argument: how can we find out precisely what the writer intended anyway?
- Attributing intent is interpretation: The attribution of a specific intent to an author is itself an act of interpretation. (Referring to the author is just a spoof to give more authority to one interpretation over another.)
- Downplaying the role of author's individual experience: an author's text is a mouthpiece of centuries of culture preceding him.
- A principled reversal of the relation between language and speaker: it is not the speaker who expresses herself through language, but language that expresses itself through the speaker.1
The salient point is that in traditional literary criticism an appeal to the author's intent or experience gives a constraint on possible interpretations and a yardstick to distinguish good and bad interpretations. With the exclusion of the author, this constrains ceases to exist. Now, an attack on the author's role in the interpretation does not necessarily lead to an unconstrained understanding of interpretation. But Barthes' consciously doesn't want to replace the author's authority with some other form of authority and opens up the interpretation game.
The multiplicity of meanings has therefore two sources: the many layers of meaning coming from "tradition"; and the plurality of readers (and their understandings) a text is exposed to. Different strains within postmodernism expound on one or the other (or both).
1 Particularly this last point had a huge impact in the development of postmodernism by the way of Jacques Derrida's deconstruction.