In an interview on The Order of Things (1966), Foucault identifies a key feature of his own method: namely that of taking up "Don Quixote, Descartes and a decree by Pomponne de Bellievre about houses of internment in the same stroke" (1998e: 262). He goes on to say that he is concerned with all that "contains thought in a culture", be it in philosophy, or a novel, in jurisprudence, in an administrative system, or in a prison (p. 267).
The apparently disparate themes that characterise Foucault's work emerge partly as a matter of his choice of fields of evidence or reference, which consists not exclusively or even predominantly of established and authoritative scientific, theoretical, or historical literature. The wide range of material and subject matter that engages Foucault's attention encompasses, for example, botanical gardens, the inscrutable orderings of species in Borges's Chinese encyclopaedia, agendas relating to executions, the daily regimens of prison and of plague towns. But, importantly, within and between these disparate elements, Foucault uncovers discursive orders and epistemic configurations that govern knowledge systems, practices, and institutions. He writes the history of events as they appear and disappear within these systems, as they become ordered and as they lose their place within the orders that once held them together.
That his investigations do not present a casual stroll through the botanical gardens of discourses, becomes clear when we look at Foucault's methodological elaborations that explicitly attempt to find the thresholds of discourses that define them, their objects, their domains of application, and most importantly for Foucault, their limits. Displacement, discontinuity, transformation, and transgression, are concepts central to Foucault's work. They attain their meanings from the exploration of the limits of discourses. It is only in paying careful attention to the threshold positions and the great aesthetic works that so often exemplify them most vividly, that it is possible to uncover both the emergence and the obsolescence of discourses. This is why, most noticeably in Foucault's archaeological writings, references to works of art, and literature are never far off.
A closer examination of the role of these texts reveals their conceptual and analytic significance. They are not merely fortuitous or decorative references; nor are they deployed illustratively in terms of their contents or their capacity to articulate moral or social criticism. Literature and art occupy a privileged position in Foucault's work as a result of their capacity to establish both systematic and symptomatic links between knowledge and art.
Attempting to categorise the ways in which Foucault engages with art, literature and music is no easy task, one which cannot hope to adequately describe the extraordinary range or depth of his work with and about literature. However, we suggest here that Foucauit values aesthetic work, firstly, because of what we have called its diagnostic power; and secondly, for its capacity not just to argue for, but to instantiate dissent or radical critique.
The first or diagnostic role is best illustrated in "The Order of Things" (1998e), a role which we hope to show is integral to the archaeological enterprise itself. In this diagnostic role artworks can elucidate the paradigmatic organisation of discourses and epistemes. It is this role that three key threshold texts ("texts" in the broader sense) assume in Foucault's "Archaeology of the Human Sciences"--Cervantes's Don Quixote, Velazquez's Las Meninas, and the writings of the Marquis de Sade. But more importantly, in their exemplary status, these texts reveal not that which is at the heart of each episteme, but the cracks, instabilities, and tectonic shifts within and between them--in the periods between the Renaissance, the Classical Age, and Modernity,--exposing their limits and transformations. …