Terry Eagleton's book Literary Theory: An Introduction (second edition, 1996) offers the following explanation (emphasis added):
The literary work continually enriches and transforms mere dictionary meaning, generating new significances by the clash and condensation of its various 'levels'. And since any two words whatsoever may be juxtaposed on the basis of some equivalent feature, this possibility is more or less unlimited. Each word in the text is linked by a whole set of formal structures to several other words, and its meaning is thus always 'overdetermined', always the result of several different determinants acting together.
This may still sound obscure: does the "set of formal structures" narrow down the set of potential meanings or expand it?
Peter Barry's book Beginning Theory: An Introduction to Literary and Cultural Theory (1995, 2002) traces the term back to the French Marxist philosopher Louis Althusser (emphasis added):
One such [concept] is the notion of overdeterminism, a word borrowed from Freud, which designates an effect which arises from a variety of causes, that is, from several causes acting
together, rather than from a single (in this case, economic) factor. This concept of linked and interacting causes is intended to undercut simplistic notions of a one-to-one correspondence between base and superstructure. A related term is the notion of relative autonomy, which is the view that in spite of the connections between culture and economics, art has a degree of independence from economic forces. This concept too is a way of attacking simplistic views of a superstructure entirely determined by the nature of the economic base.
How does this relate to literature? Barry uses the term again in a passage in which he discusses Hardy's Tess of the D'Urbervilles:
In Hardy's Tess of the D'Urbervilles, Tess's subjection to the social and physical superiority of Alec is expressed both in terms of what is said, and in terms of the grammatical structure of the 'seduction' (or 'rape' scene), for his having power is reinforced subliminally by Alec (or some attribute of him) frequently being the subject of sentences, while Tess's lack of power is reinforced by her frequently being the grammatical object: thus sentences have patterns like: he [subject] touched her [object]; his fingers [subject] sank into her [object], and so on. This kind of argument, if accepted, has implications about how literary effects are created and how they operate. The implication is that the powerful literary effect is 'overdetermined', that is, it comes from different factors combining, so that content is subtly reinforced by grammatical structure, overall 'discourse structure', word choice, imagery, and so on. Literary meaning, this suggests, goes down to the very roots of language and is reflected at the level of grammar and sentence structure.
This appears to suggest that overdetermination is a matter of linguistics or stylistics, whereas the previous quote about Althusser's concept seemed to suggest it was related to social or economic factors.
In Literary Theories: A Case Study in Critical Performance (1996), Julian Wolfreys and William Baker provide a clearer definition:
Critics use the term 'overdetermined' to indicate a text which can easily be interpreted from numerous perspectives, and which contains within it in a highly visible manner the signs of a range of discourses, topics, issues and themes. An overdetermined text is, furthermore, not ostensibly resistant to a form of interpretation.
This definition appears to explain what we read above:
- An overdetermined text "enriches and transforms mere dictionary meaning" (see Eagleton), thereby allowing interpretation from various perspectives.
- Overdetermination "arises from a variety of causes" (see Barry on Althusser): multiple "forces" may be active in a literary work; these forces may even work against each other.
This explains why literary works allow very diverse and even contradictory interpretations.