Linda Hutcheon The Politics of Postmodernism London: Routledge, 1989.
Relevant quotations from especially regarding historical metafiction:

 

Historians, like novelists, are said to be interested not in ''recounting the facts, but [in] recounting that they are recounting them.' (48)
 
Postmodern denaturalizing: ''the simultaneous inscribing and subverting of the conventions of narrative.'' 48
 
'Novels do not depict life, they depict life as it is represented by ideology'. Ideology --how culture represents itself to itself--'doxifies' or naturalizes narrative representation, making it appear as natural or common-sensical; it represents what is really constructed meaning or something inherent in that which is being represented. 49
 
In challenging the seamless quality of the history/fiction (or world/art) join implied by realist narrative, postmodern fiction does not, however, disconnect itself from history or the world. It foregrounds and thus contests the conventionality and unacknowledged ideology of that assumption of seamlessness and asks its readers to question the processes by which we represent our selves and our world to ourselves and to became aware of the means by which we make sense of and construct order out of experience in our particular culture. We cannot avoid representation. we can try to avoid fixing our notion of it and assuming it to be transhistorical and transcultural. We can also study how representation legitimizes and privileges certain kinds of knowledge -- including certain kinds of historical knowledge. 53-4
 
Among the consequences of the postmodern desire to denaturalize history is a new self-consciousness about the distinction between the brute events of the past and historical facts we construct out of them. Facts are events to which we have given meaning. Different historical perspectives therefore derive different facts from the same events. ...Postmodern fiction often thematizes this process of turning events into facts through the filtering and interpreting of archival documents. ...In historiographic metafiction the very process of turning events into facts through the interpretation of archival evidence is shown to be a process of turning the traces of the past (our only access to those events today) into historical representation. In so doing, such postmodern fiction underlines the realization that 'the past is not an ''it'' in the sense of a n objectified entity that may either be neutrally represented in and for itself or projectively reprocessed in terms of our own narrowly ''presentist'' interests'. While these are the words of a historian writing about historical representation, they also describe well the postmodern lessons about fictionalized representation.
The issue of representation in both fiction and history has usually been dealt with in epistemological terms, in terms of how we know the past. The past is not something to be escaped, avoided, or controlled -- as various forms of modernist art suggest through their implicit view of the 'nightmare' of history. The past is something with which we must come to terms and such a confrontation involves an acknowledgment of limitation s well as power. WE only have access to the past today through its traces -- its documents, the testimony of witnesses, and other archival materials. In other words, we only have representations of the past from which to construct our narratives or explanations. In a very real sense, postmodernism reveals a desire to understand present culture as the product of previous representations. The representations of history becomes the history of representation. What this means is that postmodern art acknowledges and accepts the challenge of tradition: the history of representation cannot be escaped but it can be both exploited and commented on critically through irony and parody. 57-8
 
There is an urge to foreground, by means of contradiction, the paradox of the desire for and the suspicion of narrative mastery -- and master narratives. Historiography is no longer considered the objective and disinterested recording of the past; it is more an attempt to comprehend and master it by means of some working (narrative/explanatory) model that, in fact, is precisely what grants a particular meaning to the past. ...Historiographic metafictions...ask...whether the historian discovers or invents the totalizing narrative form or model used. Of course, both discovery and invention would involve some recourse to artifice and imagination, but there is a significant difference in the epistemological value traditionally attached to the two acts. It is this distinction that postmodernism problematizes. 64

 

 

Chris Baldick. The Dictionary of Literary Terms. London: Oxford, 1990.