From thermodynamics and rocket technology to the deep web, Thomas Pynchon's novels and stories have often juxtaposed science and technology with unusual, not to say downright implausible happenings. This is perhaps the result of a fascination with contorting scientific knowledge into strange applications, whether as metaphors for social mores or to see how far its logics can be pushed toward the breaking point, but it is assuredly grounded in the relationship between the human and the technological and how American society deals with its contemporary technological environment. For example, Bleeding Edge explores the growth of the internet and the dot-com boom, Vineland focuses on television and film, and Gravity's Rainbow deals with the V2 rocket program. Obviously, such reductive statements omit the complexities of Pynchon's inclusions of and allusions to competing paradigms and conspiracy theories, but in each case what is foregrounded is how individuals understand and relate to the world. As such, it is possible to assert that Pynchon's fictions have always been involved in representing and articulating of mind. Such states might differ across his fictions in terms of their setting and context, but whether concerned with the 1893 Chicago World's Fair (Against the Day), the 9/11 attacks (Bleeding Edge), California at various points (The Crying of Lot 49, Vineland, Inherent Vice), World War Two and its aftermath (V, Gravity's Rainbow), or even colonial America (Mason & Dixon), Pynchon's works are invariably concerned with seeing things differently than established histories might otherwise imply and, moreover, foregrounding the relativism and partiality of any individual perspective or overly simplified way of perceiving the world. His protagonists search for answers to make sense of their experiences as they are cast adrift from meaning; in the case of Slothrop from Gravity's Rainbow, he is literally lost as he disappears from the narrative part way through. Within this framework, a recurrent trope of Pynchon's fictions is negative psychological responses to the environment (paranoia, uncertainty, emotional and epistemological insecurity) as a result of a failure to reconcile individual experiences with something defined as normal or normative. Pynchon's characters neither grow nor find answers, but this is precisely the point: they accumulate data, clues, and/or experiences, but no single answer suffices to define everything, and no individual's answer corresponds to any other's. As a result of this, one of the disciplines/discourses most often referenced in his fictions is psychiatry, for even when not directly connected to the narrative arc, psychological and psychiatric terminology and characters are nonetheless present and serve to lead the reader to the perception that reality is contested, not a given, and that perception is not straightforwardly schematic. More specifically, this article examines the ways in which perceptions of hallucinations--as psychiatric symptoms--have been represented in Pynchon's works and, more importantly, how they have augmented and shifted the territory upon which distinctions between hallucination and reality are founded. Within his work is a suspicion of the modes of psychiatric classifications and an attendant concern with the problems of control in the creation of such classifications, and we see this as broadly emblematic of a particular perspective evident within postmodern literature and theory. In this interpretation, Jean-Francois Lyotard's much-vaunted incredulity toward metanarratives is foreshadowed within Pynchon's oeuvre as a suspicion towards those who would describe and define reality at the expense of other worldviews (xxiv). (1) After a brief examination of how theorists such as Fredric Jameson and Jean Baudrillard have represented postmodern society, this essay moves on to explore the problems of binary-based psychiatric definitions of hallucinations. …